Scientific Studies Database By Natural Foundation

We've collected over 1000 studies on the products we sell. We've compiled the most interesting studies on this page.

We stay on top of the latest scientific research to ensure our products are as effective and safe as possible.

Nattokinase Scientific Studies

Several studies have explored the effects of nattokinase, an enzyme derived from the fermented soybean cheese natto. We’ve compiled the most interesting findings on its impact on cholesterol levels, arterial plaque formation, the risk of cardiovascular mortality, and blood pressure.

Study 1

Study type: 

Randomised, double-blind, placebo-controlled trial 

Purpose:

To examine the effects of nattokinase on heart health indicators in people with dyslipidemia (abnormal levels of fats in the blood).

Dose:

5000 FU/day 

Participants:

113 men and women with an average age of 59 years

Duration:

120 days

Results:

The researchers observed a significant reduction in total cholesterol of −13.75 mmol/L in the nattokinase group after 120 days of treatment, while the placebo group saw a small decrease −4.16 mmol/L. Similarly, for LDL “bad” cholesterol, the nattokinase group demonstrated a significant decrease of −12.82 mmol/L, whereas the placebo group experienced an increase of 1.83 mmol/L. This suggests that this natural supplement could be a helpful addition to managing high cholesterol.

Year:

2023

Link:

https://doi.org/10.3390/nu15194239 

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial 

Purpose:

To investigate the effects of nattokinase combined with red yeast rice in patients with coronary artery disease.

Dose:

1. Nattokinase + Red Yeast Rice Group: 3661.8 FU/day nattokinase and 9mg monacolins

2. Nattokinase Only Group: 3615.0 FU/day

3. Red Yeast Rice Only Group: 9 mg monacolins (6 x 1.5 mg capsules)

4. Placebo Group

Participants:

178 men and women with an average age of 62 years

Duration:

90 days

Results:

The group taking nattokinase combined with red yeast rice showed the largest significant reductions in triglycerides (−0.39 mmol/L), total cholesterol (−0.66 mmol/L), and diastolic blood pressure (−7.39 mmHg), along with a significant increase in HDL “good” cholesterol (+0.195 mmol/L) compared to other groups. 

Year:

2024

Link:

https://doi.org/10.3389/fnut.2024.1380727  

Study 1

Study type: 

Randomised controlled trial 

Purpose:

To evaluate the effect of nattokinase in reducing carotid artery thickness and carotid plaque (fatty deposits) size. The carotid arteries are two major blood vessels on each side of the neck that supply oxygen-rich blood to the brain, face, and head. Plaque buildup in these artery walls can thicken them, leading to blockages and raising the risk of heart disease and stroke.

Dose:

6000 FU/day of nattokinase or 20 mg/day of simvastatin (common medication to lower bad cholesterol levels)

Participants:

86 men and women 

Duration:

26 weeks 

Results:

After 26 weeks of treatment, the nattokinase group demonstrated a significant reduction in plaque area and artery wall thickness. The plaque area decreased from 0.25 to 0.16 cm², and artery thickness dropped from 1.13 to 1.01 mm. This reduction was much greater than in the control group, with a decrease of -36.6% in the nattokinase  group compared to -11.5% in the control group. A reduction in plaque area and artery wall thickness means that the buildup of fatty deposits (plaque) within the artery walls has decreased, and the artery walls themselves have become thinner. This improvement increases blood flow, lowers the risk of blockages, and reduces the chances of heart attack and stroke.

Year:

2017

Link:

https://doi.org/10.3760/cma.j.issn.0376-2491.2017.26.005 

Study 2

Study type: 

Retrospective observational study

Purpose:

To evaluate the clinical effects of nattokinase on the management of atherosclerosis (a condition where fatty deposits build up inside the arteries) and hyperlipidemia (high levels of fats in the blood).

Dose:

3600/day FU or 10,800 FU/day of nattokinase 

Participants:

1,062 men and women with an average age of 68 years

Duration:

12 months

Results:

After 12 months of daily nattokinase supplementation, 95.4% of participants demonstrated significant improvement in total cholesterol, 85.2% in triglycerides, 84.3% in LDL “bad” cholesterol, and 89.1% in HDL “good” cholesterol.

Additionally, the researchers observed that the thickness of the carotid artery wall—the layer of the main neck artery supplying blood to the brain—and the size of artery plaque, a buildup of fats and cholesterol, were significantly reduced. The average artery wall thickness dropped from 1.33 mm to 1.04 mm, and plaque size decreased by up to 36%. These results suggest that nattokinase may be effective in keeping arteries clear by reducing plaque buildup, supporting better blood flow, heart health, and lowering the risk of heart attack and stroke.

Year:

2022

Link:

https://doi.org/10.3389/fcvm.2022.964977 

Study 1

Study type: 

Cohort observational study

Purpose:

To examine the association of cardiovascular disease mortality with the intake of natto, soy protein, and soy isoflavones.

Dose:

Approximately 0, 1.4, 2.7, or 7.3 g/day of natto (median values)

Participants:

13,355 male and 15,724 female participants with an average age of 55 years 

Duration:

16 years of follow-up 

Results:

The study found that higher intake of natto was significantly associated with a reduced risk of death from cardiovascular disease and stroke. Those in the highest natto intake had a 25% lower risk of  cardiovascular disease mortality compared to those with the lowest intake. Additionally, high intake of natto was associated with a 31% lower risk of death from all types of stroke. For ischemic stroke specifically, the highest natto consumers had a 33% lower risk of death.

Year:

2017

Link:

https://doi.org/10.3945/ajcn.116.137281 

Study 1

Study type: 

Randomised, double-blind, placebo-controlled trial 

Purpose:

To examine the effects of nattokinase supplementation on blood pressure

in subjects with borderline high blood pressure or early-stage high blood pressure.

Dose:

2000 FUs/day of nattokinase or placebo

Participants:

86 men and women with an average age of 47 years

Duration:

8 weeks 

Results:

The study found a significant association between 8 weeks of nattokinase supplementation and reduced blood pressure compared to the control group. In the nattokinase group, systolic blood pressure significantly decreased by an average of 13.26 mmHg, while the control group saw a smaller reduction of 7.7 mmHg. Diastolic blood pressure also dropped significantly in the nattokinase group by 5.67 mmHg, compared to 2.82 mmHg in the control group. These findings suggest that nattokinase could be beneficial for lowering blood pressure,

Year:

2008

Link:

https://doi.org/10.1291/hypres.31.1583 

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial 

Purpose:

To explore the effects of nattokinase on blood pressure and other cardiovascular risk markers in adults with high blood pressure.

Dose:

100 mg/2000 FUs/day nattokinase or placebo

Participants:

79 hypertensive men and women with an average age of 53 years

Duration:

8 weeks 

Results:

The study found that 8 weeks of nattokinase supplementation significantly reduced diastolic blood pressure, especially in males. Overall, diastolic blood pressure decreased from 87 mmHg to 84 mmHg in the nattokinase group, and from 86 mmHg to 81 mmHg in males. Notably, among participants with low blood renin levels—an enzyme that helps regulate blood pressure by controlling the balance of salt and water in the body—66% showed improvement with nattokinase, compared to only 8% in the placebo group. These findings suggest that nattokinase may be a useful alternative for managing high blood pressure.

Year:

2016

Link:

https://doi.org/10.2147/IBPC.S99553   

Study 1

Study type: 

Cellular study

Purpose:

To examine the effect of nattokinase on COVID-19 virus

Results:

The researchers found that nattokinase could break down a key protein on the surface of the COVID-19 virus, which the virus needs to enter human cells. By breaking down this protein, nattokinase could reduce the virus's ability to infect cells. Importantly, the enzyme was effective at safe levels and did not harm healthy cells, and the effectiveness of nattokinase increased as the dosage increased.

These results suggest that nattokinase could have potential as a natural way to help prevent COVID-19 infections.

Year:

2022

Link:

https://doi.org/10.3390/molecules27175405 

PRODUCTS CONTAINING NATTOKINASE

Blood Pressure Support Scientific Studies

Our Blood Pressure Support product is designed with key ingredients backed by scientific studies. It includes high-nitrate beetroot, potassium, and magnesium, which are known to support healthy blood pressure levels. Research indicates that these nutrients, in effective doses, can promote cardiovascular health safely and naturally. We have summarised the most interesting scientific studies.

Study 1

Study type: 

Randomised, double-blind, placebo-controlled feasibility trial 

Dose

Participants were randomly assigned to consume either:

1. High-nitrate beetroot juice (∼400 mg nitrate) and folic acid (∼5 mg folic acid) (N+F)

2. High-nitrate beetroot juice and placebo (N+P)

3. Nitrate-depleted beetroot juice and placebo (P+P)

Participants:

47 men and women aged 50 to 70 with BMIs between 26 and 29

Duration:

60 days

Results:

The study found an association between drinking beetroot juice, which contains dietary nitrate, and significantly lowered blood pressure. By the end of the study, those in the group that combined nitrate and folic aacid had the biggest drop in 24-hour systolic blood pressure (−10.8 mmHg) and a significant decrease in diastolic blood pressure (−5.4 mmHg). The other groups, nitrate with fruit and just a placebo, showed smaller or no significant changes.

Year:

2020

Link:

https://doi.org/10.1093/jn/nxaa170  

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

250 mL/day of beetroot juice (containing ~6.4mmol of nitrate) or a placebo (250 mL of nitrate-depleted beetroot juice)

Participants:

64 hypertensive men and women aged 18 to 85 

Duration:

4 weeks 

Results:

The researchers observed that daily supplementation with beetroot juice, which is high in dietary nitrate, significantly reduced blood pressure. The reduction in blood pressure was similar to what is typically seen with a standard dose of blood pressure medication. These significant results suggest that dietary nitrate from beetroot juice may be used as an additional therapy for managing high blood pressure..

Year:

2014

Link:

https://doi.org/10.1161/HYPERTENSIONAHA.114.04675 

Study 3

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

314 mM of nitrate tablets or a placebo (nitrate-free tablets). The nitrate tablets consisted of nitrate-rich beetroot extract 20mg, thiamine mononitrate 90mg, potassium nitrate 480mg, ascorbic acid 150mg, folic acid 200mcg, methylcobalamin 200mcg, calcium 115mg, pomegranate fruit extract 5mg and green coffee bean extract 115mg. Ascorbic acid was added to facilitate NO bioavailability.

Participants:

67 hypertensive men and women with a mean age of 59

Duration:

12 weeks

Results:

The study found that nitrate tablets significantly reduced blood pressure, more so than a placebo. The upper number (systolic) dropped by 12.5 mmHg, while the lower number (diastolic) dropped by 4.7 mmHg. In contrast, the placebo group saw smaller or no significant changes. Additionally, the nitrate tablets improved endothelial function, which helps blood vessels work better. The researchers concluded that nitrate tablets effectively lower blood pressure and improve blood vessel health in people with high blood pressure.

Year:

2020

Link:

https://doi.org/10.1016/j.clnesp.2020.08.007 

Study 4

Study type: 

Randomised, single-blind, cross-over postprandial trial (pilot study)

Dose:

In study 1, participants were randomly assigned to consume either 0, 100, 250 or 500mL of beetroot juice (each having a nitrate concentration of <0.5, 2.3, 5.7 and 11.4 mmol respectively). In study 2, participants were randomly assigned to consume either 200g of unfortified bread (<0.5 mmol of nitrate) or 200g of bread fortified with white or red beetroot (1.6 and 1.8 mmol of nitrate respectively). All participants consumed a low-nitrate/nitrite diet for 1 day before each study.

Participants:

18 healthy normotensive males in study 1 and 14 healthy normotensive males in study 2.  

Duration:

Acute: blood pressure was measured over a 24h period following the consumption of beetroot juice, beetroot-fortified bread and the controls.

Results:

Supplementation with beetroot juice or beetroot-fortified bread was associated with larger reductions in blood pressure than the control. The peak reduction in blood pressure occurred after 2-3 hours:

- 100mL of beetroot juice was associated with a 13.1/16.6 mmHg reduction in blood pressure. 

- 250mL of beetroot juice was associated with a 20.5/14.6 mmHg reduction in blood pressure.

- 500mL of beetroot juice was associated with a 22.2/18.3 mmHg reduction in blood pressure.

- Bread fortified with white beetroot was associated with a 19.3/16.5 mmHg reduction in blood pressure.

  • Bread fortified with red beetroot was associated with a 23.6/23.2 mmHg reduction in blood pressure.

These results suggest that nitrate in beetroot may significantly help to reduce blood pressure. The reductions in blood pressure after the consumption of fortified bread suggest that processed beetroot may lower blood pressure to a similar degree as unprocessed beetroot. Thus, beetroot supplements may help to reduce overall blood pressure.

Year:

2015

Link:

https://doi.org/10.1017/S0007114512000190

Study 5

Study type: 

Randomised non-blinded postprandial trial

Dose:

The experimental group consumed 500mL of beetroot juice with a mean nitrate concentration of 45.0±2.6 mMol/L (2.79g/L). The control group consumed water.

Participants:

14 healthy subjects  

Duration:

Acute: blood pressure was measured over a 24h period following the consumption of beetroot juice. 

Results:

Beetroot juice supplementation (dietary nitrate) was associated with larger reductions in blood pressure than the control. Specifically, blood pressure dropped by 10.4/8 mmHg after 2.5 hours compared to the control. The drop in blood pressure was correlated with increases in plasma nitrite concentration. This suggests that dietary nitrate may underlie the beneficial effects of beetroot. After 24 hours, systolic blood pressure was 4.4 mmHg lower with beetroot juice than water.

Year:

2008

Link:

https://doi.org/10.1161/HYPERTENSIONAHA.107.103523 

Study 6

Study type: 

Randomised non-blinded crossover trial

Dose

250mL of beetroot juice (containing 5.5 mmol of nitrate) or placebo (250mL of water)

Participants:

9 healthy men and women.

Duration:

Acute (less than 24 hours)

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a 5.4 mmHg reduction in systolic blood pressure. The authors suggested that a dietary nitrate approach to cardiovascular disease may have therapeutic use.

Year:

2010

Link:

https://doi.org/10.1161/HYPERTENSIONAHA.110.153536  

Study 7

Study type: 

Randomised, double-blind, crossover trial

Dose

2 x 70 mL/day of organic beetroot juice (each containing 4.8 mmol of nitrate). The placebo consumed nitrate-depleted beetroot juice.

Participants:

12 healthy, normotensive, non-smoking, older adults (6 males and 6 female)

Duration:

2.5 days

Results:

2.5 days of dietary nitrate supplementation was associated with a four-fold increase in plasma nitrite concentration and significant reductions in resting blood pressure. More specifically, plasma nitrite increased to 418% of the placebo value, and blood pressure decreased by 5/3 mmHg relative to the placebo (115/70 vs 120/73 mmHg). The authors suggested that nitrate supplementation could potentially reduce the risk of hypertension and cardiovascular disease in older adults.

Year:

2013

Link:

https://doi.org/10.1152/ajpregu.00406.2012  

Study 8

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

Nitrate-rich beetroot juice (12.9 mmol of nitrate) or a placebo (nitrate-depleted beetroot juice (0.5 mmol of nitrate)

Participants:

20 men and women (mean age: 62.5) with uncontrolled hypertension 

Duration:

7 days

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a significant reduction in systolic and diastolic blood pressure compared to the placebo. Beetroot juice supplementation was also significantly associated with increased plasma nitrite. Significant decreases in 24h (−8/−4 mmHg) and day blood pressure (−9/−4 mmHg) profiles were observed.

Year:

2018

Link:

https://doi.org/10.1017/S0007114518000144   

Study 9

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

150 mL of nitrate-rich beetroot juice (10.5 mmol of nitrate) or a placebo (1 mmol nitrate) 2.25 hours prior to a 30-min treadmill walk

Participants:

13 younger (18–30) and 11 older (50–70) normotensive adults

Duration:

Acute (3.5 hours)

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a significant reduction in systolic blood pressure in both age groups and diastolic blood pressure in older adults. Beetroot juice was also associated with increased plasma nitrate and nitrite concentrations.

The authors concluded that acute supplementation with beetroot may reduce blood pressure.

Year:

2019

Link:

https://doi.org/10.3390/nu11071683 

Study 10

Study type: 

Randomised, placebo-controlled, single-blind crossover trial

Dose:

140 mL of beetroot juice (containing 7.58 millimoles of nitrate) or a placebo (163 ml of prune juice with less than 0.01 millimoles of nitrate)

Participants:

15 patients with chronic obstructive pulmonary disease (11 males and 3 females)

Duration:

48 hours

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a significant reduction in resting systolic blood pressure (-8 mmHg), end-of-exercise diastolic blood pressure (-5 mmHg) and a trend for a decrease in resting diastolic blood pressure (−3 mmHg). Beetroot juice was also associated with increased plasma nitrate (+938%) and nitrite (+379%) relative to the placebo.

The authors concluded that dietary nitrate supplementation may reduce blood pressure and elevate plasma nitrate and nitrite concentrations. 

Year:

2015

Link:

https://doi.org/10.1016/j.niox.2014.10.007 

Study 11

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

Nitrate-rich beetroot juice (500mg/8.1mmol of nitrate) or a placebo (nitrate-depleted beetroot juice with less than 0.08 mmol of nitrate) 

Participants:

18 untreated hypertensives aged 44 on average.

Duration:

Acute (8 hours)

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a larger reduction in ambulatory systolic and diastolic blood pressure (-6.7/-5.2 mmHg) compared to the placebo (-0.8/-1.7 mmHg) after 8 hours.

Year:

2018

Link:

https://doi.org/10.1111/micc.12525 

Study 12

Study type: 

Randomised controlled trial

Dose:

∼5.76 mmol of nitrate in the form of a concentrated beetroot juice drink (55 mL), a non-concentrated beetroot juice drink (456 mL) and a solid beetroot flapjack (60 g). A drink containing soluble beetroot crystals (∼1.40 mmol of nitrate) and a control drink (70mL of deionised water) were also ingested.

Participants:

10 healthy males

Duration:

Acute (24 hours)

Results:

Beetroot juice (dietary nitrate) was associated with lower blood pressure and higher concentrations of nitric oxide metabolites. All nitrate-rich vehicles in the study were associated with elevated plasma, salivary and urinary nitric oxide metabolites compared with baseline and the control.

Year:

2018

Link:

https://doi.org/10.1016/j.niox.2017.12.001 

Study 13

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

70mL of beetroot juice (400 mg of nitrate) or a placebo (nitrate-depleted beetroot juice)

Participants:

14 healthy males (aged 22 on average) 

Duration:

15 days

Results:

Compared with the placebo, beetroot juice (dietary nitrate) was associated with reductions in systolic and diastolic blood pressure, mean arterial pressure and total peripheral resistance at rest and during exercise.

Beetroot juice was also associated with significant increases in baseline concentrations of plasma nitrate and nitrite compared to the placebo.

Year:

2015

Link:

https://doi.org/10.1152/ajpregu.00099.2015 

Study 14

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

500 mL/day of beetroot juice (containing ∼6.2 mmol of nitrate) or a placebo (500 mL/day of nitrate-depleted beetroot juice)

Participants:

9 normotensive, physically active males

Duration:

6 days

Results:

Short-term supplementation with beetroot juice (dietary nitrate) was associated with significant increases in plasma nitrite (+105%) and reductions in systolic blood pressure (-5 mmHg) in normotensive young men consuming a normal, balanced diet. The placebo had no effect on systolic, diastolic or mean arterial blood pressure.

Year:

2011

Link:

https://doi.org/10.1152/japplphysiol.01070.2010 

Study 15

Study type: 

Randomised double-blind crossover trial

Dose

24 mmol of potassium nitrate (1488mg of nitrate) in capsules or a placebo (24 mmol of potassium chloride)

Participants:

21 healthy men and women

Duration:

Acute (less than 24 hours)

Results:

Potassium nitrate supplementation was associated with substantial reductions in systolic and diastolic blood pressure over 24 hours, whereas a similar dose of potassium chloride did not alter blood pressure over the same time period. These findings suggest that the changes in blood pressure were not attributable to the potassium content. Instead, the changes were likely dependent on the endogenous conversion to nitrite and, thereupon, to nitric oxide: the changes in plasma nitrite correlated closely with reductions in blood pressure.

Kapil et al.’s findings also showed dose-dependent reductions in systolic blood pressure with incremental doses of inorganic nitrate (4mmol and 12mmol).

Year:

2010

Link:

https://doi.org/10.1161/HYPERTENSIONAHA.110.153536  

Study 16

Study type: 

Systematic review

Intervention under study:

Beetroot juice (dietary inorganic nitrate) supplementation

Studies reviewed:

11 randomised controlled trials published between 2008 and 2018 

Results:

The review concluded that supplementation with beetroot juice may reduce blood pressure in different populations, probably through the nitrate-nitrite/nitric oxide pathway and secondary metabolites found in beetroot. The review also concluded that beetroot juice may significantly decrease the risk of suffering cardiovascular events, and the authors believe that beetroot juice should be promoted as a key component of a healthy lifestyle to control blood pressure in healthy and hypertensive individuals.

Year:

2018

Link:

https://doi.org/10.3390/biom8040134 

Study 17

Study type: 

Systematic review and meta-analysis

Intervention under study:

Dietary nitrate supplementation

Outcome under study:

Medium-term effects of dietary nitrate supplementation on systolic and diastolic blood pressure.

Studies included:

13 randomised clinical trials with 7 to 65 participants per study. Most of the trials were placebo-controlled (75%). 

Results:

Overall, dietary nitrate supplementation for more than one week was associated with a significant decrease in systolic and diastolic blood pressure. The pooled effect for the two interventions showed a reduction in systolic blood pressure (-4.1 mmHg) and diastolic blood pressure (-2.0 mmHg). 

Year:

2017

Link:

https://doi.org/10.1097/HJH.0000000000001305 

Study 18

Study type: 

Systematic review and meta-analysis

Intervention under study:

Dietary nitrate supplementation. The intervention time ranged from 3 to 60 days with daily dosages of 70–250 mL of beetroot juice.

Outcome under study:

The role of dietary nitrate in lowering blood pressure in patients older than 18 with arterial hypertension ( > 130/80 mmHg).

Studies included:

7 single/double-blinded randomised controlled trials published between 2013 and 2020.

Results:

Inorganic nitrate derived from beetroot juice was associated with reductions in systolic blood pressure in patients with arterial hypertension. The authors concluded that dietary nitrate from beetroot juice may be an effective method to reduce the blood pressure of patients with arterial hypertension (in interventions up to 2 months duration).

Year:

2022

Link:

https://doi.org/10.3389/fnut.2022.823039 

Study 19

Study type: 

Systematic review and meta-analysis

Intervention under study:

Dietary inorganic nitrate/nitrite

Outcome under study:

Prevention and treatment of cardiovascular disease risk factors in humans

Studies included:

34 studies were included for qualitative synthesis, 23 of which were eligible for meta-analysis.

Results:

Inorganic nitrate intake was associated with significant reductions in resting blood pressure (systolic blood pressure: -4.80 mmHg; diastolic blood pressure: 1.74 mmHg).

Year:

2018

Link:

https://doi.org/10.1093/nutrit/nuy005 

Study 20

Study type: 

Randomised, double-blind, placebo-controlled trial 

Dose

Beetroot juice with 6.5–7.3 mmol of nitrate. The placebo group received nitrate-depleted beetroot juice(<0.06 mmol nitrate)

Participants:

15 healthy, normotensive men and women aged 22 to 40

Duration:

Acute: 24 hours on two occasions (crossover)

Results:

Supplementation with beetroot juice containing inorganic nitrate was associated with lower aortic systolic blood pressure after 30 minutes (-5.2 mmHg).

Year:

2019

Link:

https://doi.org/10.3389/fphys.2019.00047  

Study 21

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

70mL of beetroot juice (6.1 mmol nitrate). The placebo group consumed 70mL of nitrate-depleted beetroot juice.

Participants:

20 patients suffering from heart failure with preserved ejection fraction (aged 69 on average) 

Duration:

First phase: acute (24 hours)

Second phase: 1 week 

Results:

In both study phases, supplementation with nitrate-rich beetroot juice was associated with significant reductions in systolic blood pressure (resting) and increases in plasma nitrate and nitrite. After a single, acute dose of nitrate-rich beetroot juice, resting systolic blood pressure was significantly lower than the placebo (127 mmHg vs. 134 mmHg).

Compared to the placebo, plasma nitrite levels increased significantly after the nitrate-rich beetroot juice (38% after an acute dose and 129% after 1 week of daily doses).

The authors concluded that beetroot may significantly improve blood pressure in elderly patients with heart failure.

Year:

2016

Link:

https://doi.org/10.1016/j.jchf.2015.12.013   

Study 22

Study type: 

Randomised placebo-controlled crossover trial

Dose

500 mL/day of beetroot juice (5.2 mmol of nitrate/day) and placebo (500 mL/day of juice). Participants also engaged in moderate-intensity exercise after 2.5 hours and on day 5 and day 15. 

Participants:

8 healthy subjects (5 males and 3 females) with an average age of 29

Duration:

Acute (2.5 hours) and chronic (up to 15 days)

Results:

Nitrate-rich beetroot juice supplementation was associated with significantly lower systolic and diastolic blood pressure throughout the supplementation period (∼-4%). It was also associated with significantly elevated plasma nitrite concentration (+39% after 2.5 hours; +25% after 5 days; and +46% after 15 days).

The results indicate that dietary NO3− supplementation may acutely reduce blood pressure, and that this effect may be maintained for at least 15 days if supplementation is continued. 

Year:

2010

Link:

https://doi.org/10.1152/ajpregu.00206.2010 

Study 23

Study type: 

Randomised unblinded crossover trial

Dose:

Participants were assigned either:

1. 200mL of beetroot juice (with ~800mg of nitrate) and 40 minutes of moderate-intensity aerobic exercise

2. 200mL of low-nitrate fruit soda and the same exercise 

3. 200mL of water (insignificant nitrate) and no exercise.

Participants:

14 non-hypertensive obese males

Duration:

Acute (24 hours)

Results:

Compared to the control, supplementation with beetroot juice (dietary nitrate) was associated with a reduction in systolic ambulatory blood pressure (-5.3 mmHg) up to 6 hours after ingestion and moderate-intensity aerobic exercise. Beetroot juice supplementation was also associated with a significantly higher plasma nitric oxide concentration up to 1 hour after ingestion.

The authors concluded that inorganic nitrate may have important therapeutic applications to decrease the blood pressure response to exercise when individuals have an increased cardiovascular risk.

Year:

2019

Link:

https://pubmed.ncbi.nlm.nih.gov/30787659/ 

Study 24

Study type: 

Uncontrolled clinical trial

Intervention:

Beetroot juice concentrate and blackcurrant juice 

Participants:

21 men and women

Duration:

3 weeks 

Results:

Beetroot juice concentrate was associated with a ~7.3mmHg reduction in daily systolic blood pressure after 3 weeks. However, beetroot juice supplementation was not associated with significant changes in resting clinic blood pressure or 24h ambulatory blood pressure.

Year:

2016

Link:

https://doi.org/10.3945/ajcn.115.116244 

Study 25

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

500 mL/day of either nitrate-rich beetroot juice (containing 5.1 mmol of nitrate/day) or placebo (a drink with negligible nitrate content

Participants:

7 men aged 19 to 38

Duration:

6 days

Results:

Overall, systolic and diastolic was significantly lower after 6 days of nitrate supplementation (-7/7 mmHg). Relative to the placebo, nitrate supplementation was associated with reductions in systolic blood pressure (-5 mmHg), diastolic blood pressure (-2 mmHg) and mean arterial pressure (-2 mmHg).

Year:

2010

Link:

https://doi.org/10.1152/japplphysiol.00046.2010 

Study 26

Study type: 

Randomised, double-blind, placebo-controlled crossover trial

Dose:

0.11 mmol of nitrate per kg of body weight (a body mass-normalised moderate dose of nitrate) via beetroot juice.

Participants:

11 patients with peripheral artery disease

Duration:

Acute (∼1 hour)

Results:

Compared to the placebo, dietary nitrate supplementation was associated with reductions in peripheral and central systolic blood pressure (−4.7 mmHg and −8.2 mmHg, respectively) and significant increases in serum nitrate/nitrite level.

The authors concuded that acute, body mass-normalised, moderate doses of dietary nitrate may improve blood pressure and nitric oxide bioavailability.

Year:

2021

Link:

https://doi.org/10.1152/ajpregu.00121.2021 

Study 27

Study type: 

Randomised crossover trial

Dose:

∼400mg of nitrate at lunch, provided through nitrate-rich vegetables or beetroot juice supplementation

Participants:

15 healthy men and women (aged 24 on average)

Duration:

1 week

Results:

Nitrate-rich vegetables and beetroot juice supplementation were associated with increases in plasma nitrate concentrations and reductions in mean systolic and diastolic blood pressure throughout both intervention periods (∼2.5 hours after lunch).

Year:

2020

Link:

https://doi.org/10.1016/j.jand.2020.02.014 

Study 28

Study type: 

Systematic review and meta-analysis

Intervention under study:

Dietary inorganic nitrate (with doses ranging from 150 to 1000mg over a treatment range from 7 to 168 days).

Outcome under study:

Effect of repeated administrations of inorganic nitrate on blood pressure and arterial stiffness.

Studies included:

47 randomised controlled trials, including 1101 participants (including healthy, overweight, hypertensive, diabetic and hypercholesterolemic individuals, and patients with heart failure and peripheral artery disease).

Results:

The results found that inorganic nitrate supplementation was associated with an overall beneficial effect on blood pressure. Repeated (≥ 3 days) administrations of inorganic nitrates were associated with reductions in peripheral and central blood pressure.

Year:

2020

Link:

https://doi.org/10.1097/HJH.0000000000002524 

Study 29

Study type: 

Open-label randomised controlled trial

Dose:

70mL of beetroot concentrate (containing ~300 to 400mg of nitrate)

Participants:

21 overweight men and women between the ages of 55 and 70

Duration:

28 days 

Results:

Supplementation with beetroot juice (dietary nitrate) was associated with a 10.2/3.1 mmHg reduction in blood pressure after 3 weeks of supplementation. 

Year:

2015

Link:

https://doi.org/10.1038/jhh.2014.114 

Study 1

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effect of potassium citrate or potassium chloride on blood pressure in volunteers with normal blood pressure.

Dose:

30 mmol/day of potassium citrate or potassium chloride or placebo

Participants:

127 men and women with an average age of 36 years

Duration:

6 weeks

Results:

The researchers observed significantly lowered blood pressure after taking potassium citrate for 6 weeks by about 5.22 mmHg. This reduction was similar to the 4.70 mmHg drop seen with potassium chloride. In addition, both forms of potassium reduced the upper and lower numbers of blood pressure, showing that potassium may help manage blood pressure levels.

Year:

2008

Link:

https://doi.org/10.1017/S0007114507864853 

Study 2

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the long-term supplementation of potassium intake on blood pressure.

Dose:

7156.8 mg/day of potassium or placebo

Participants:

17 patients with essential hypertension (high blood pressure without any identifiable cause) with an average age of 29 years

Duration:

8 weeks

Results:

The study found an association between long-term potassium supplementation and significantly lowered blood pressure without changing salt intake. The average upper blood pressure value (systolic) significantly dropped from 152.2 mmHg to 137.4 mmHg, and the lower value (diastolic) significantly decreased from 99.6 mmHg to 89.1 mmHg. This effect was stronger in people with higher starting blood pressure and those who excreted more potassium. Lowering both systolic and diastolic blood pressure is important because it reduces the strain on your heart and arteries, lowering the risk of heart attacks, strokes, and other heart problems.

Year:

1985

Link:

https://doi.org/10.1007/BF01731654

Study 3

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effects of short-term potassium supplementation on blood pressure in women with normal blood pressure 

Dose:

3,128 mg/day of potassium or placebo 

Participants:

39 healthy women with an average age of 32 years 

Duration:

4 days

Results:

The researchers observed that potassium supplementation for 4 days significantly lowered systolic blood pressure by about 2 mmHg in normal blood pressure. 

Year:

1991

Link:

https://doi.org/10.1093/ajh/4.3.206 

Study 4

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effect of long term oral potassium supplement in patients with mild hypertension.

Dose:

1876.8 mg/day of potassium supplements or placebo

Participants:

37 patients who had mildly increased blood pressure with an average age of 45 years

Duration:

15 weeks

Results:

By the third week, the researchers observed a significant decrease in blood pressure in the potassium group compared to the placebo group, with the maximum decrease occurring after 15 weeks. A subgroup of 13 patients who continued for an additional nine weeks with oral potassium supplements at half the previous daily dosage showed a moderate increase in blood pressure during this period compared to the values at the end of the full-dose treatment. At the end of this second study period, their blood pressure was still significantly lower than the values at the start of the study but not compared to the placebo group.

Year:

1987

Link:

https://doi.org/10.1136/bmj.294.6585.1453 

Study 5

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effects of potassium chloride on blood pressure in older adults with hypertension

Dose:

4692 mg/day of potassium chloride or placebo

Additional interventions:

A balanced diet that maintains the same calorie count daily (isocaloric diet) containing 4598 mg/day of sodium, 2737 mg/day of potassium, and 500 mg/day of calcium

Participants:

22 patients aged 60 years and older with mild to moderate essential hypertension

Duration:

8 days

Results:

During the potassium chloride treatment, the researchers observed that the participants’ average systolic blood pressure (upper value of BP reading) significantly dropped by 8.6 mmHg and diastolic blood pressure (lower value of BP reading) significantly dropped by 4.0 mmHg. There was no significant change in blood pressure with the placebo. Lowering both systolic and diastolic blood pressure reduces heart strain, decreases the risk of heart disease, and improves overall cardiovascular health. 

Year:

1992

Link:

https://doi.org/10.1681/ASN.V281302 

Study 6

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To evaluate the effect of a lower dose of potassium aspartate salt on blood pressure in individuals with essential arterial hypertension, a condition where a person has high blood pressure in their arteries without any specific identifiable cause.

Dose:

1173 mg/day of potassium aspartate or placebo

Participants:

104 male and female patients with an average age of 53 years

Duration:

4 weeks 

Results:

The researchers observed that the control group showed no change in blood pressure, while the potassium supplementation group demonstrated significant reductions. For the potassium group, the average office blood pressure (measured at the doctor's office) significantly dropped from 154.4  mmHg to 142.2 mmHg, and the average 24-hour blood pressure (measured continuously over 24 hours using a portable monitor) significantly decreased from 142.7 mmHg to 134.8 mmHg. Overall, a relatively low dose of 1173 mg/day of potassium as aspartate may help lower blood pressure in people with mild to moderate high blood pressure.

Year:

2021

Link:

https://doi.org/10.1016/j.biopha.2004.11.002

Study 7

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To explore the effects of potassium supplementation on blood pressure in hypertensive individuals.

Dose:

60 mmol of potassium or 40 g of soybean protein

Participants:

150 hypertensive men and women with an average age 56 years

Duration:

12 weeks

Results:

The researchers observed that after 12 weeks of potassium supplementation, those who took potassium supplements demonstrated a significant drop in their systolic blood pressure (upper number of the blood pressure reading) and a decreasing trend in their diastolic blood pressure (lower number of the blood pressure reading). This could suggest that the supplement may be particularly effective in reducing the strain on the heart during active pumping. 

Year:

2001

Link:

https://doi.org/10.1097/00004872-200107000-00019  

Study 8

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To explore the effects of low-dose potassium supplementation on blood pressure in healthy volunteers.

Dose:

24 mmol/d of potassium or placebo

Participants:

59 male and female volunteers with an average age of 43 years

Duration:

6 weeks 

Results:

The researchers observed that taking a low-dose potassium supplement daily for six weeks significantly lowered overall, systolic, and diastolic blood pressure in healthy volunteers. The greatest reduction was observed in those with a higher sodium-to-potassium ratio in their urine. This is beneficial because potassium helps balance the negative effects of sodium (salt) in the body. Studies have shown that consuming salt is often linked to high blood pressure, especially in salt-sensitive individuals. Overall, the findings suggest that taking potassium supplementation even at a low dosage may help improve blood pressure and overall heart health.

Year:

2003

Link:

https://doi.org/10.1079/bjn2003861 

Study 9

Study type: 

Randomised crossover trial

Purpose:

To investigate the effects of potassium supplementation in patients with hypertension

Dose:

64 mmol/day of potassium

Participants:

55 patients with essential hypertension

Duration:

4 weeks

Results:

The study found an association between taking potassium supplements and significantly reduced blood pressure in people with high blood pressure. This reduction was observed in blood pressure readings taken at the doctor's office, at home, and over a full day while on potassium supplements compared to when they weren't taking the supplements.

Year:

1998

Link:

https://doi.org/10.1016/s0895-7061(98)00037-5 

Study 10

Study type: 

Clinical trial (Uncontrolled)

Purpose:

To investigate the effects of salt loading and potassium supplementation in individuals with normal blood pressure or mild hypertension.

Dose:

60 mmol /day of potassium

Additional interventions:

Low- and high-salt diet

Participants:

155 men and women with either normal blood pressure or mild hypertension.

Duration:

Around 4 weeks (1 week potassium supplementation at the final week)

Results:

The researchers observed that potassium supplements significantly reduced blood pressure and levels of endothelin-1 (a protein that tightens blood vessels) more in salt-sensitive people than in those who are not salt-sensitive. Salt-sensitive individuals have a greater increase in blood pressure when consuming salt, so dietary changes affect them more. Overall, the study highlights that potassium supplements can provide significant health benefits, especially for those sensitive to salt, who are more likely to have high blood pressure.

Year:

2013

Link:

https://doi.org/10.1111/jch.12109 

Study 1

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effects of magnesium supplementation on blood pressure in diabetic hypertensive adults with low magnesium levels.

Dose:

450 mg/day of magnesium, administered over a 4-month period.

Participants:

79 male and female diabetic hypertensive patients with an average age of 60 years old

Duration:

4 months

Results:

The study found an association between magnesium supplementation and significantly reduced blood pressure in diabetic hypertensive adults with low blood magnesium levels, compared to placebo. Additionally, the researchers also observed significantly increased HDL (good) cholesterol levels following magnesium supplementation. The study also found that people with lower magnesium levels in their blood are 2.8 times more likely to have high blood pressure compared to those with normal magnesium levels. Overall, magnesium may be a useful treatment for lowering blood pressure, especially in people with low magnesium levels.

Year:

2009

Link:

https://doi.org/10.1038/jhh.2008.129 

Study 2

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effect of oral magnesium supplementation on blood pressure, in clinically healthy volunteers, including those with slightly high blood pressure or mildly high cholesterol.

Dose:

411-548 mg/day of magnesium or placebo

Participants:

33 male and female subjects with normal blood pressure or have borderline hypertension

Duration:

4 weeks 

Results:

The group that took magnesium saw a significant decrease in their blood pressure, while the group that took a placebo did not. A decrease in both systolic (upper value of BP reading) and diastolic (lower value of BP reading) blood pressure means that the overall pressure in your blood vessels is lower, which is generally beneficial for heart health. 

Year:

1997

Link:

https://doi.org/10.1079/bjn19970191 

Study 3

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effect of oral magnesium supplementation on blood pressure in patients with mild hypertension

Dose:

1200 mg/day of magnesium (2 x 600 mg) or placebo

Participants:

28 mild hypertensive adults with an average age of 46 years

Duration:

12 weeks

Results:

The study found an association between oral magnesium supplementation and a significant reduction in 24-hour blood pressure. The researchers also observed that magnesium levels in the blood significantly increased in those taking the supplements, while no significant change in the control group.

Year:

2009

Link:

https://doi.org/10.1038/ajh.2009.126 

Study 4

Study type: 

Single-arm non-blinded intervention study

Purpose:

To examine the effects of oral magnesium supplementation on blood pressure in patients with essential hypertension, a condition where a person has high blood pressure in their arteries without any specific identifiable cause.

Dose:

300 mg/day of oral magnesium-oxide supplementation

Participants:

48 men and women with essential hypertension

Duration:

1 month

Results:

The study found an association between magnesium supplements and significant decrease in blood pressure. On average, systolic pressure significantly dropped from 139.7 to 130.8 mmHg, and diastolic pressure significantly decreased from 88.0 to 82.2 mmHg.

Year:

2018

Link:

https://doi.org/10.3390/nu10050581 

Study 5

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To observe the effects of oral magnesium-potassium supplementation on arterial compliance in essential hypertension. Arterial compliance refers to the ability of arteries to expand and contract with blood flow. High compliance means flexibility, while low compliance indicates stiffness, which can lead to high blood pressure and cardiovascular issues.

Dose:

70.8 mg/day of magnesium and 217.2 mg/day of potassium or control  (lacidipine, a common antihypertensive medication)

Participants:

Treatment group: 35 male and female hypertensive patients with an average age  of 58 years 

Positive control group: 32 male and female hypertensive patients with an average age  of 56 years
Control group: 147 healthy male and females with an average age of 54 years

Duration:

4 weeks

Results:

Patients taking magnesium and potassium supplements demonstrated an average significant decrease in their blood pressure levels. However, this decrease was less than what was observed in patients taking lacidipine, a common antihypertensive medication.

The researchers also observed that those taking magnesium and potassium supplements showed significantly improved flexibility of smaller arteries (arteries farther from the heart), while those taking lacidipine showed significantly improved flexibility of larger arteries (arteries closer to the heart). 

Overall, magnesium and potassium mainly improved small artery flexibility, whereas lacidipine significantly improved large artery flexibility, suggesting that these two interventions may have different effects on arterial compliance based on the size of the arteries they target. 

Year:

2006

Link:

https://doi.org/10.1080/10641960600798705 

Study 6

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effects of magnesium supplementation in women with mild to moderate hypertension.

Dose:

485 mg of magnesium/day (485 mg) as magnesium aspartate-HCI or placebo

Participants:

91 women, with an average age of 57 years old

Duration:

6 months

Results:

By the end of the study, researchers observed that the group taking magnesium supplements had a significantly larger decrease in diastolic blood pressure (the pressure in your arteries when your heart is resting between beats), which was 3.4 mm Hg more compared to the placebo group. There was also a trend toward reduced systolic blood pressure (the pressure in your arteries when your heart beats).

Year:

1994

Link:

https://doi.org/10.1093/ajcn/60.1.129 

Study 7

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effects of magnesium supplementation on blood pressure in Brazilian hypertensive patients.

Dose:

600 mg of magnesium/day (3 x 200 mg) or placebo

Participants:

15 male and female adults aged 35-65 years

Duration:

3 weeks 

Results:

The study found that oral magnesium supplementation lowers blood pressure. The effect was stronger in patients with a shorter duration of high blood pressure, with around 40% reported a significant reduction of more than 10 mmHg. Magnesium supplements may be particularly effective for those with recent high blood pressure.

Year:

1995

Link:

https://doi.org/10.1016/0167-5273(96)02716-7 

Study 8

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To evaluate the effects of oral magnesium supplementation in individuals with metabolic syndrome and who have low levels of magnesium in the blood

Dose:

382 mg/day of elemental magnesium (30 mL of magnesium chloride

5% solution) or a placebo solution

Participants:

198 men and women with an average age of 40 years 

Duration:

16 weeks 

Results:

Researchers observed significant improvements in participants who received magnesium supplementation. These included a significant drop in systolic blood pressure (the top number) by 3.6 mmHg and diastolic blood pressure (the bottom number) by 5.5 mmHg compared to placebo. In addition, the researchers also observed a significant decrease in fasting blood sugar levels, significant reduction in triglyceride levels, and a significant increase in the amount of magnesium in the blood.

Year:

2017

Link:

https://doi.org/10.1053/j.ackd.2018.02.011 

Study 9

Study type: 

Randomised, double-blinded, placebo-controlled clinical trial

Purpose:

To investigate the effect of magnesium treatment on blood pressure in patients with mild essential hypertension

Dose:

1-3 weeks: 15 mmol/day of magnesium or placebo

4-6 weeks: 30 mmol/day of magnesium or placebo

7-9 weeks: 40 mmol/day of magnesium or placebo

Participants:

17 mild hypertensive men and women with an average age of 50 years 

Duration:

9 weeks

Results:

The study found an association between magnesium supplementation and a significant dose-dependent reduction in blood pressure in patients with mild essential hypertension. In other words, the more magnesium they took, the greater the decrease in their blood pressure. Meanwhile, the placebo group did not show any significant changes in their blood pressure.

Year:

1993

Link:

https://doi.org/10.1093/ajh/6.1.41 

Study 10

Study type: 

Pilot study

Purpose:

To evaluate the effects of magnesium in individuals with metabolic syndrome and have normal magnesium levels.

Dose:

400 mg/day of magnesium in the form of magnesium citrate or placebo

Participants:

42 men and women with metabolic syndrome and have an average age of 66 years (24 completed the study)

Duration:

12 weeks 

Results:

The researchers observed a significant drop in both the top and bottom blood pressure numbers in the group taking magnesium for 12 weeks compared to their blood pressure at the beginning of the study. The top number, which shows the pressure when the heart beats, decreased from 145 to 120.8 mmHg, and the bottom number, which shows the pressure when the heart rests, went down from 85.4 to 78.5 mmHg. They also noticed a significant decrease in blood sugar levels after taking magnesium compared to the placebo group. These findings suggest that magnesium supplementation might help manage certain aspects of metabolic syndrome, especially blood pressure and blood sugar.

Year:

2021

Link:

https://doi.org/10.1684/mrh.2021.0489 

PRODUCTS CONTAINING BLOOD PRESSURE SUPPORT

Easy Sleep Scientific Studies

The effects of our Easy Sleep product have been thoroughly studied through various clinical trials and research. We've highlighted some of the most interesting scientific findings on key ingredients like lemon balm, Sensoril® ashwagandha extract, chamomile, apigenin, magnesium bisglycinate, L-theanine, and tart cherry powder.

Study 1

Study type: 

Randomised, double-blind, placebo controlled trial

Purpose:

To assess the effects of lemon balm on sleep quality of postmenopausal women. Research has shown that sleep disorder is one of the most common problems in menopausal women. 

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called the Pittsburgh Sleep Quality Index, which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Dose:

500 mg/day lemon balm extract (2 x 250 mg capsules) or placebo

Participants:

110 postmenopausal women with an average age of 53 years 

Duration:

1 month

Results:

The researchers observed a significant improvement in sleep quality in the lemon balm group compared to the control group after 1 month of intervention. These results suggest that lemon balm may be a beneficial, natural option for enhancing sleep quality over a relatively short period of time.

Year:

2020

Link:

https://www.scholarsresearchlibrary.com/articles/evaluation-of-extract-efficacy-of-lemon-balm-on-sleep-quality-score-in-postmenopausal-women-a-doubleblinded-randomized-c.pdf 

Study 2

Study type: 

Randomised, double-blind, placebo controlled trial

Purpose:

To determine the effects of lemon balm supplementation on depression, anxiety, stress, and sleep disturbances in patients with chronic stable angina, a type of chest pain that happens during physical activity or stress due to reduced blood flow to the heart.

Method of evaluation:

Sleep quality was assessed before and after the intervention using the Pittsburgh Sleep Quality Index, a self-reported questionnaire which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Dose:

3,000 mg/day of lemon balm (3 x 1,000 mg capsules) or placebo 

Participants:

73 men and women with an average age of 58 years

Duration:

8 weeks

Results:

The researchers observed a significant decrease in the total sleep disorder score in the intervention group compared to the control group after treatment. Specifically, the intervention group demonstrated better sleep quality, longer sleep duration, and improved sleep efficiency compared to the control group. 

Year:

2018

Link:

https://doi.org/10.1016/j.clnesp.2018.04.015 

Study 3

Study type: 

Randomised, double-blind, placebo controlled trial

Purpose:

To evaluate the effects of lemon balm on anxiety and sleep quality in patients undergoing coronary artery bypass surgery. Studies have shown that anxiety and sleep disorders are common following surgery, often affecting recovery and overall well-being.

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called St. Mary’s Hospital Sleep Questionnaire, which measures the severity of sleep disorder. 

Dose:

1500 mg/day lemon balm (3 x 500 mg capsules) or placebo 

Participants:

80 men and women with an average age of 58 years

Duration:

7 days

Results:

The participants in the lemon balm group showed a significantly greater improvement in sleep quality and lower anxiety scores compared to the placebo group. Overall, the researchers observed that lemon balm improved sleep quality by 54% and reduced anxiety by 49% in patients after coronary artery bypass surgery.

Year:

2019

Link:

https://doi.org/10.1016/j.eujim.2019.01.010 

Study 1

Study type: 

Randomised, placebo-controlled, crossover, and double-blind trial

Purpose:

To examine the effects of L-theanine on cognitive functions and stress-related symptoms, including sleep disorders, in healthy adults.

Method of evaluation:

Stress-related symptoms were assessed using self-reported questionnaires, including the Self-rating Depression Scale for depression, the State-Trait Anxiety Inventory for anxiety, and the Pittsburgh Sleep Quality Index for sleep quality and disturbances. The study also utilised several cognitive assessments to evaluate the effects of L-theanine on cognitive functions.

Dose:

200 mg/day of L-theanine or placebo 

Participants:

30 men and women with an average age of 48 years

Duration:

4 weeks

Results:

Participants who took L-theanine demonstrated significant improvements in overall sleep quality, with less trouble falling asleep, fewer disturbances, and less need for sleep medication compared to the placebo. Additionally, cognitive skills improved, and stress-related symptoms like depression and anxiety decreased. Overall, the study suggests that L-theanine may enhance both sleep and mental performance more effectively than the placebo.

Year:

2019

Link:

https://doi.org/10.3390/nu11102362 

Study 2

Study type: 

Open, randomised, crossover intervention trial

Purpose:

To investigate the effects of known sleep-support supplements, including L-theanine, on life habits, sleep conditions, and sleep problems.

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called the Pittsburgh Sleep Quality Index, which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Dose:

Treatment 1: 200 mg/day of L-theanine

Treatment 2: 111.1 mg/day of GABA

Treatment 3: 50 mg/day of Apocynum venetum leaf extract

Treatment 4: 300 mg/day of L-serine

Treatment 5: Mindfulness video

Treatment 6: Placebo 

Participants:

106 male and female participants with an average age 46 years

Duration:

7 days of intervention per group

Results:

The researchers observed that L-theanine significantly improved sleep quality, especially for individuals struggling to fall asleep, stay asleep, or feel refreshed in the morning. People with good habits, such as less screen time and regular exercise, showed significantly better results. This suggests that combining physical activity and healthy lifestyle habits with L-theanine may lead to better sleep.

Year:

2023

Link:

https://doi.org/10.3390/nu15102377 

Study 3

Study type: 

Randomised, double-blind, placebo controlled, crossover trial

Purpose:

To investigate the effects of L-theanine in combination with alpha-s1-casein tryptic hydrolysate (a protein derived from cow's milk) on sleep quality in working adults with sleep disorders/insomnia. 

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called the Pittsburgh Sleep Quality Index, which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Dose:

50 mg/day of L-theanine with 150 mg/day of alpha-s1-casein tryptic hydrolysate (CTH) or placebo 

Participants:

39 men and women with an average age of 37 years 

Duration:

4 weeks 

Results:

The study found a significant association between L-theanine combined with alpha-s1-casein and improved sleep quality. The participants in the L-theanine group reported falling asleep faster, sleeping longer, and having better-quality sleep, while also feeling more alert during the day. In addition, those who took the supplement slept 45 minutes longer than those who took a placebo, with the biggest improvements seen in both sleep duration and sleep quality. 

Year:

2021

Link:

https://doi.org/10.3390/nu14030652 

Study 4

Study type: 

Clinical trial (uncontrolled)

Purpose:

To examine the effects of L-theanine on depressive symptoms, anxiety, sleep disturbance, and cognitive impairments in patients with major depressive disorders

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called the Pittsburgh Sleep Quality Index, which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Dose:

250 mg/day L theanine tablets

Participants:

20 male and female patients with an average age of 43 years

Duration:

8 weeks

Results:

The study found that L-theanine administration is associated with a significant improvement in sleep disturbance among patients with major depressive disorder. The study also noted that some patients reported increased sleep duration and slightly increased dream activity, suggesting a positive impact on sleep patterns. 

Year:

2016

Link:

https://doi.org/10.1017/neu.2016.33   

Study 5

Study type: 

Randomised, placebo-controlled, double-blind, crossover trial

Purpose:

To explore the sleep-improving effects of a lower dose L-theanine (100 mg/day) in middle-aged and older men.

Method of evaluation:

Sleep quality was assessed using a portable electroencephalogram (EEG) monitoring device, which measures brain activity during sleep. Participants placed sensors on their forehead and behind their ears, which tracked how long they slept, how quickly they fell asleep, time spent in deep and light sleep, and how often they woke up.

Dose:

100 mg/day of L-theanine or placebo

Participants:

24 men with an average age of 47 years

Duration:

1 week 

Results:

Overall, there was no significant difference in sleep quality between the theanine and placebo groups. However, for those under 50 and participants who drank green tea less than 3-4 times a week, the researchers observed that theanine significantly improved stage 2 non-REM sleep. Stage 2 non-REM sleep helps lower heart rate, cool the body, and rest the brain, leading to more refreshing and higher-quality sleep. 

Year:

2022

Link:

https://doi.org/10.33425/2641-4295.1051 

Study 6

Study type: 

Randomised, single-blind, placebo-controlled trial 

Purpose:

To evaluate the effects of a combination of magnesium, vitamins B6, B9, B12, rhodiola, and L-theanine (Mg-Teadiola) on stress and stress-related quality of life parameters, including sleep and pain perception, in chronically stressed individuals.

Method of evaluation:

Sleep quality was assessed before and after the intervention using the Pittsburgh Sleep Quality Index, a self-reported questionnaire which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction.

Dose:

125 mg/d L-theanine with 150 mg/day of magnesium, 222 mg/d rhodiola, 0.7 mg vit B6, 0.1 mg of vit B9, and 1.25 mcg vit B12, or placebo

Participants:

100  chronically stressed, bu otherwise healthy men and women aged 18-65 years

Duration:

28 days

Results:

Mg-Teadiola showed potential for improving sleep-related quality of life, particularly in significantly reducing daytime dysfunction due to sleepiness in the longer term. The study also found an association between Mg-Teadiola supplementation and significant decreases in stress scores. 

Year:

2022

Link:

https://doi.org/10.3390/nu14091863 

Study 1

Study type: 

Randomised, double-blind, placebo-controlled clinical trial 

Purpose:

To investigate the effects of ashwagandha (Sensorill®) in chronically stressed adults

Method of Evaluation:

Sleep quality and related parameters were assessed using three different measurement tools which collectively measure a comprehensive assessment of sleep quality , sleep disturbances, and overall well-being. 

Dose:

125, 250, and 500 mg/d of ashwagandha (Sensorill®) capsules or placebo 

Participants:

97 chronically stressed men and women with an average age of 35 years 

Duration:

8 weeks

Results:

The researcher observed that participants consuming the standardised Withania somnifera extract (Sensoril) experienced positive effects on sleep quality. This improvement is linked to the extract's ability to reduce stress levels, which is known to affect sleep negatively

Year:

2024

Link:

https://doi.org/10.3390/nu16091293 

Study 1

Study type: 

Randomised controlled clinical trial 

Purpose:

To investigate the effects of chamomile extract on melatonin levels in subjects suffering from insomnia and anxiety.

Dose:

15 ml/day of chamomile extract

Participants:

50 male and female participants, aged 18-60 years

Duration:

60 days

Results:

The researchers observed a significant increase in melatonin levels after treatment with chamomile extract compared to those not taking it (0.55 vs. 0.17 ng/mL). The researchers also observed significant decreases in triglyceride (a type of fat found in the blood) and cholesterol levels.

Year:

2022

Link:

https://doi.org/10.51248/.v42i6.2269 

Study 2

Study type: 

Single-blind, randomised, controlled clinical trial 

Purpose:

To evaluate the effects of chamomile extract on sleep quality among elderly people. Research has shown that insomnia tends to be more common as people age.

Method of evaluation:

Sleep quality was assessed by interviewing participants at four time points: before the treatment started, two weeks into it, right after it finished, and two weeks after it ended. 

Dose:

400 mg/day of chamomile extract (2 x 200 mg capsules) or placebo (wheat flour capsules)

Participants:

60 men and women with an average age of 70 years 

Duration:

28 days

Results:

At the beginning of the study, participants in both the treatment and placebo groups had poor sleep quality. However, after 28 days of treatment, those taking chamomile extract capsules reported a significant improvement in their sleep quality compared to the placebo group. Given that sleep problems are common in older adults and many sleep medications may have harmful side effects, the authors recommended chamomile extract as a safe way to help improve sleep in the elderly.

Year:

2017

Link:

https://doi.org/10.1016/j.ctim.2017.09.010  

Study 3

Study type: 

Quasi-experimental clinical trial

Purpose:

To determine the effect of chamomile extract on sleep quality in elderly people admitted to nursing homes

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire which measures subjective sleep quality.

Dose:

400 mg/day of chamomile extract (2 x 200 mg capsules) or control (no intervention)

Participants:

77 men and women with an average age of 74 years

Duration:

4 weeks

Results:

Results of this study showed an association between 4 weeks consumption of chamomile extract and significant improvements in sleep quality. 

Year:

2017

Link:

https://doi.org/10.4103/jehp.jehp_109_15 

Study 4

Study type: 

Single-blind, randomised, controlled clinical trial 

Purpose:

To evaluate the effects of chamomile tea on sleep quality, fatigue, and depression in postpartum women

Method of evaluation:

Sleep quality, fatigue, and depression were assessed using standardised self-reported questionnaires that measured subjective sleep quality, postpartum depression, and perceived fatigue.

Dose:

2 g/day of chamomile dried flowers (in one tea bag steeped in 300 ml hot water for 10-15 minutes)

Participants:

80 postnatal women with an average age of 33 years (72 completed the study)

Duration:

2 weeks

Results:

Postnatal women who drank chamomile tea for 2 weeks saw a noticeable improvement in their sleep problems and symptoms of depression. These benefits were limited to the immediate term meaning, the effects only lasted while they were drinking the tea and did not continue once they stopped.

Year:

2015

Link:

https://doi.org/10.1111/jan.12836 

Study 1

Study type: 

Observational studies

Purpose:

To explore the association between sleep quality and specific dietary polyphenols (natural compounds found in plants that act as antioxidants) including apigenin in Italian adults. 

Method of evaluation:

Sleep quality was assessed using a self-reported questionnaire called the Pittsburgh Sleep Quality Index, which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. 

Participants:

1936 men and women with an average age of 50 years

Results:

The study found a significant association between apigenin and sleep quality. The researchers observed that people who consumed more apigenin were less likely to experience poor sleep. This suggests that a higher intake of apigenin may improve sleep quality. While other polyphenols were also studied, such as flavonoids and lignans, apigenin showed a more pronounced effect on sleep quality, indicating that apigenin may be more effective than its polyphenol counterparts in promoting better sleep

Year:

2020

Link:

https://doi.org/10.3390/nu12051226 

Study 1

Study type: 

Randomised, double-blind, placebo-controlled, crossover clinical trial 

Purpose:

To investigate the effects of tart cherry juice for the treatment of insomnia in older adults. 

Method of evaluation:

Sleep quality was measured using self-reported health questionnaires and other validated questionnaires (the Insomnia Severity Index, the Epworth Sleepiness Scale, and the Pittsburgh Sleep Quality Index), which assess insomnia severity, sleepiness, and overall sleep quality.

After two weeks of drinking either cherry juice or a placebo, participants had an overnight polysomnography sleep study, which also assesses sleep quality and identifies any sleep disorders. 

Dose:

480 mL/day of tart cherry juice (2 x 240 mL) or placebo

Participants:

8 men and women with an average age of 68 years

Duration:

2 weeks per treatment

Results:

The researchers observed that participants who consumed tart cherry juice experienced an increase in sleep time by 84 minutes, as measured by polysomnographic sleep study, which is a reliable method for assessing sleep quality. Sleep efficiency, or the percentage of time spent actually sleeping while in bed, also improved significantly based on the Pittsburgh Sleep Quality Index. While the study utilised other validated questionnaires to assess sleep quality, other questionnaires did not show significant differences. Overall, tart cherry juice appears to positively affect sleep quality, as evidenced by both polysomnography and the Pittsburgh Sleep Quality Index questionnaire. 

Year:

2018

Link:

https://doi.org/10.1097/MJT.0000000000000584 

Study 2

Study type: 

Open label clinical trial (uncontrolled)

Purpose:

To investigate the effects of a compound containing Montmorency tart cherry extract and Apocynum venetum on sleep and anxiety in adults with insomnia 

Method of evaluation:

Insomnia was assessed using a self-assessed questionnaire (Insomnia Sleep Index), which measures the severity of insomnia. 

Dose:

553 mg/day of tart cherry extract with 25 mg/day of Apocynum venetum

Participants:

46 men and women with an average age of 36 years

Duration:

4 weeks 

Results:

The researchers observed that bedtime consumption of tart cherry extract and Apocynum venetum significantly reduced insomnia severity and anxiety scores while also improving self-reported sleep quality and daytime alertness. Furthermore, sleep quality and alertness continued to improve week by week throughout the study. 

Year:

2024

Link:

https://doi.org/10.17605/OSF.IO/F8YV9 

Study 3

Study type: 

Randomised, double-blind, placebo-controlled,  crossover pilot study

Purpose:

To investigate the effects of a tart cherry juice beverage on sleep in older adults with insomnia.

Method of evaluation:

Insomnia was assessed using the Insomnia Severity Index (ISI), a validated seven-item questionnaire that measures difficulty falling asleep, staying asleep, daytime impacts, concerns about sleep, and overall satisfaction with sleep quality. In addition, participants maintained daily sleep diaries throughout the study period.

Dose:

16-ounce tart cherry juice (2 x 8 ounce) or placebo beverage 

Participants:

15 men and women with insomnia, with an average age of 72 years

Duration:

8 weeks

Results:

The study found an association between a special tart cherry juice blend and significant improvements on sleep in older adults with insomnia. Specifically, the study showed a significant decrease in the time spent awake after falling asleep, and participants reported better overall sleep quality after drinking the juice compared to a placebo. Overall, the findings suggest that tart cherries may have promising benefits for improving sleep.

Year:

2010

Link:

https://doi.org/10.1089/jmf.2009.0096   

Study 1

Study type: 

Randomised, double-blind, placebo-controlled trial 

Purpose:

To investigate the effect of magnesium supplementation on insomnia in elderly.

Method of evaluation:

Insomnia was assessed using the Insomnia Severity Index (ISI), a seven-item questionnaire measuring sleep difficulties and satisfaction. Participants also kept daily sleep logs to track their sleep time.

Dose:

500 mg/d elemental magnesium (2 x 250 mg tablets) or placebo 

Participants:

43 men and women with an average age of 65 years

Duration:

8 weeks

Results:

The researchers observed that participants who took magnesium supplements had significant improvements compared to the placebo group. These included significantly longer sleep time, better sleep efficiency, higher levels of serum renin and melatonin, and a significant decrease in insomnia severity, time to fall asleep, and stress levels. They also observed trends in reduced early morning awakenings and increased magnesium levels.

Year:

2012

Link:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3703169/ 

Study 2

Study type: 

Randomised, single-blind, placebo-controlled trial 

Purpose:

To evaluate the effects of a combination of magnesium, vitamins B6, B9, B12, rhodiola, and L-theanine (Mg-Teadiola) on stress and stress-related quality of life parameters, including sleep and pain perception, in chronically stressed individuals.

Method of evaluation:

Sleep quality was assessed before and after the intervention using the Pittsburgh Sleep Quality Index, a self-reported questionnaire which measures seven areas: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction.

Dose:

150 mg/day of magnesium with 125 mg/d L-theanine, 222 mg/d rhodiola, 0.7 mg vit B6, 0.1 mg of vit B9, and 1.25 mcg vit B12, or placebo

Participants:

100  chronically stressed, bu otherwise healthy men and women aged 18-65 years

Duration:

28 days

Results:

Mg-Teadiola showed potential for improving sleep-related quality of life, particularly in significantly reducing daytime dysfunction due to sleepiness with longer use. The study also found an association between Mg-Teadiola supplementation and significant decreases in stress scores. 

Year:

2022

Link:

https://doi.org/10.3390/nu14091863 

Study 3

Study type: 

Case histories (Case #1)

Purpose:

To determine the effects of magnesium supplementation in individuals with major depressive disorder

Dose:

300 mg/d of magnesium as glycinate and later as taurinate

Participant:

A 59-year-old male with a history of mild depression, previously managed with antidepressants, suddenly developed severe anxiety, insomnia, muscle spasms, and suicidal depression after a year of intense stress and poor dietary habits.

Results:

The subject reported that after the first night of starting magnesium, his sleep returned to near normal. Over the next four days, depression was significantly reduced for 4-6 hours after each dose, anxiety gradually faded, and headaches quickly disappeared. In the months that followed, normalcy was maintained only by frequent magnesium ingestion.

Year:

2006

Link:

https://doi.org/10.1016/j.mehy.2006.01.047 

PRODUCTS CONTAINING BLOOD PRESSURE SUPPORT

Tongkat Ali Scientific Studies

Numerous clinical trials have investigated the effects of tongkat ali in humans over the past 20 years. We have summarised some of the most important studies related to testosterone, sexual function, stress and energy.

Study 1

Study type: 

Clinical trial (double-blind, placebo-controlled)

Dose:

600 mg/day of Tongkat Ali with 1.45% eurycomanone

Participants:

32 men aged from 20 to 30  

Duration:

2 weeks

Results:

The researchers observed steroidogenic effects after Tongkat Ali supplementation. No adverse side effects were observed. 

600mg/day was correlated with significant increases in testosterone (15%), free testosterone (34%) and estrogen (30%) levels. The testosterone level was raised slightly above the normal human range. The authors concluded that 600mg/day of Tongkat Ali could have a positive impact on sports performance.

Link:

https://doi.org/10.1111/and.14001

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

50mg of Tongkat Ali per day

Additional interventions:

Multivitamin mix

Participants:

95 men and women aged from 25 to 65

Duration:

24 weeks

Results:

Tongkat Ali supplementation was associated with significant increases in free testosterone. Males experienced a 682% average increase in free testosterone. Females experienced a 700% average increase in free testosterone.

Year:

2018

Link:

https://doi.org/10.29219/fnr.v62.1374  

Study 3

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

100mg or 200mg of Tongkat Ali per day

Participants:

106 males aged from 50 to 70 with low testosterone

Duration:

12 weeks

Results:

Tongkat ali supplementation was associated with significant increases in total testosterone. A dose of 200mg per day was associated with a 12.2% increase in total testosterone and a 16.9% increase in free testosterone. 

Year:

2021

Link:

https://doi.org/10.29219/fnr.v65.5647 

Study 4

Study type: 

Randomised double-blind placebo-controlled trial

Dose:

200mg of Tongkat Ali per day 

Additional interventions:

3 hour-long training sessions per week

Participants:

45 middle-aged, androgen-deficient males

Duration:

6 months (the longest trial of tongkat ali supplementation to date)

Results:

Tongkat Ali supplementation was associated with increases in total testosterone levels and improvements in erectile function.

Year:

2020

Link:

https://doi.org/10.1016/j.maturitas.2020.12.002 

Study 5

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

200mg of Tongkat Ali per day

Participants:

26 men aged from 45 to 60 with mild erectile dysfunction

Duration:

12 weeks

Results:

Tongkat Ali supplementation was associated with a 36% increase in total testosterone. No adverse effects were observed; liver and kidney values showed no significant changes from baseline.

Link:

https://doi.org/10.1155/2014/179529

Study 6

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

200mg of Tongkat Ali per day

Participants:

32 men and 31 women experiencing moderate stress

Duration:

4 weeks

Results:

Tongkat Ali supplementation was associated with a 37% increase in testosterone and an improved cortisol:testosterone ratio.

Link:

https://doi.org/10.1186/1550-2783-10-28

STUDY 7

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

200mg, 400mg and 600mg of Tongkat Ali per day

Participants:

20 healthy males aged from 38 to 58  

Duration:

2 months

Results:

Testosterone levels increased after 3 weeks of Tongkat Ali supplementation. The high dose of 600mg/d did not adversely affect liver function, renal function, blood profiles, electrolytes, cancer markers and the immune system.

Link:

https://www.researchgate.net/publication/295384337_Standardized_watersoluble_extract_of_eurycoma_longifolia_LJ100_on_men's_health 

Study 8

Study type: 

Systematic review and meta-analysis

Studies:

9 studies in the systematic review and 5 studies in the meta-analysis

Results:

The systematic review revealed that most studies reported a significant improvement in total testosterone levels after Tongkat Ali supplementation. The meta-analysis suggested that Tongkat Ali could improve testosterone production.

Link:

https://doi.org/10.3390/medicina58081047

Study 9

Study type: 

Uncontrolled trial

Dose:

200mg of Tongkat Ali per day

Participants:

76 men with hypogonadism

Duration:

4 weeks

Results:

Tongkat Ali supplementation was associated with a 46.6% average increase in serum testosterone concentrations (from 5.66 nM to 8.3 nM). The participants also experienced improvements in erectile function and libido.

Link:

https://doi.org/10.1111/j.1439-0272.2011.01168.x

Study 10

Study type: 

Uncontrolled trial

Dose:

200mg of Tongkat Ali per day

Participants:

13 physically active males and 12 physically active females aged 57 to 72

Duration:

5 weeks

Results:

Tongkat Ali was associated with significant increases in total and free testosterone concentrations and muscular force. Males experienced a 61% increase in free testosterone and a 15.1% increase in total testosterone. Females experienced a 122% increase in free testosterone and a 48.6% increase in total testosterone.

Link:

https://doi.org/10.1002/ptr.5017

Study 11

Study type: 

Animal study (male rats)

Dose:

4 fractions of Tongkat Ali at a dosage of 25 mg/kg body weight

Results:

Tongkat ali (F2) and eurycomanone significantly increased the testosterone level from the Leydig cells. The plasma luteinizing hormone and follicle stimulating hormone were also higher than the control group.

Link:

https://doi.org/10.1016/j.jep.2012.11.013

Study 12

Study type: 

Cellular study (testicular interstitial cells)

Dose:

100μL solution of Eurycomanone at 0.1, 1.0 and 10μM

Results:

Eurycomanone significantly increased testosterone production dose-dependently at 0.1, 1.0 and 10.0 μM.

Link:

https://doi.org/10.1016/j.jep.2013.06.023

Study 1

Study type: 

Placebo-controlled clinical trial

Dose:

100mg per day

Additional interventions:

Intense strength training on alternate days

Participants:

14 healthy men

Duration:

5 weeks

Results:

Tongkat Ali supplementation was associated with:

• 4.1% Increase in lean body mass (from 52.26kg to 54.39kg) 

• 2.86% reduction in body fat (from 31.3% to 28.44%)

• 6.8% increase in strength

• 1.8cm increase in mean arm circumference (from 30.87cm to 32.67cm)

Link:

https://www.researchgate.net/publication/341998425_The_Ergogenic_Effect_of_Eurycoma_longifolia_Jack_A_Pilot_Study 

Study 2

Study type: 

Randomised placebo-controlled trial

Dose:

250mg of Tongkat Ali per day

Additional interventions:

High-intensity resistance training; 2500mg of branched-chain amino acids; 1020mg of beta-alanine. 

Participants:

32 young males with at least 1 year of experience in squatting, bench pressing and deadlifting.

Duration:

4 weeks

Results:

Tongkat Ali supplementation was associated with large strength increases in bench pressing (102kg to 108kg), squatting (120kg to 133kg) and deadlifting (158kg to 172kg), corresponding to an overall strength increase of 33kg. The placebo group experienced a much lower overall strength increase (24kg).

Year: 

2015

Link:

https://www.doi.org/10.1519/JSC.0000000000000995     

Study 3

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

300mg

Participants:

40 men aged 30 to 35

Duration:

12 weeks

Results:

Tongkat Ali supplementation was associated with a strength increase of around 14kg in the back and leg muscles compared to the placebo group.

Year: 

2013

Link:

https://doi.org/10.4172/2161-0673.1000127 

Study 4

Study type: 

Clinical trial (uncontrolled)

Dose:

200mg per day

Participants:

13 physically active males and 12 physically active females aged 57 to 72

Duration:

5 weeks

Results:

Tongkat Ali supplementation was associated with a strength increase of 16.6% in men and 13.7% in women after 5 weeks. These increases in muscle strength indirectly reflected an increase in muscle mass.
* Strength was measured with a hand dynamometer. 

Year:

2013

Link:

https://doi.org/10.1002/ptr.5017  

Study 1

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

300mg of Tongkat Ali per day

Participants:

109 healthy men aged from 30 to 55

Duration:

12 weeks

Results:

Tongkat Ali was associated with significant improvements in erectile function, sexual libido and overall sexual satisfaction scores. Tongkat Ali was also associated with higher sperm motility and semen volume. The study also indicated that healthy, younger males may require doses higher than 300mg per day to increase testosterone levels. 

Year: 

2012

Link:

https://doi.org/10.1155/2012/429268  

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

200mg per day

Participants:

26 men aged from 45 to 60 with mild erectile dysfunction 

Duration:

12 weeks

Results:

Tongkat Ali supplementation was associated with significant improvements in the frequency of sexual performance, sexual satisfaction, penile erection and hardness, and overall sexual wellbeing. Participants also experienced an average increase in total testosterone by 36%. No adverse effects were observed; liver and kidney values showed no significant changes from baseline.

Year: 

2014

Link:

https://doi.org/10.1155/2014/179529 

Study 3

Study type: 

Clinical trial (uncontrolled)

Dose:

200mg per day

Participants:

75 males (aged 33 on average) with idiopathic infertility

Duration:

3 months

Results:

Tongkat Ali supplementation was associated with significantly improved sperm quality (higher semen concentration, sperm motility and sperm concentration) and 11 spontaneous pregnancies. 

Link:

https://doi.org/10.1038/aja.2010.7  

Study 1

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

50mg of Tongkat Ali per day

Additional interventions:

Multivitamin mix

Participants:

95 men and women aged from 25 to 65

Duration:

24 weeks

Results:

Tongkat Ali supplementation was associated with significant improvements in reported stress levels, quality-of-life, mood, vigour, emotional well-being and cognition.

Year:

2018

Link:

https://doi.org/10.29219/fnr.v62.1374  

Study 2

Study type: 

Randomised, double-blind, placebo-controlled trial

Dose:

200mg per day

Participants:

32 men and 31 women experiencing moderate stress

Duration:

4 weeks

Results:

Tongkat Ali supplementation was associated with significant improvements in tension (-11%), confusion (-15%) and anger (-21%). Tongkat Ali was also associated with a reduction in cortisol (−16%) and increased testosterone (+37%). Note that cortisol levels generally increase in response to stress.

Year: 

2022

Link:

https://doi.org/10.1186/1550-2783-10-28 

TURKESTERONE SCIENTIFIC STUDIES

Several studies have investigated the effects of turkesterone. We have summarised the most interesting results.

Study 1: Turkesterone outperforms anabolic steroids

Study type: 

Rodent study (male rats)

Purpose

To compare the anabolic activity of phytoecdysteroids and steranabols (anabolic steroids). Specifically, turkesterone and ecdysterone were compared with methyandrostenediol (Anabol) and nerobol (Dianabol). The effect of phytoecdysteroids upon protein-anabolic processes were judged by changes in body weight and the weight of internal organs and skeletal muscles. 

Dose:

5 mg/kg/day of phytoecdysteroids for 10 days or 10 mg/kg/day of Dianabol/Anabol for 10 days.

Results:

The results showed that the anabolic activity of turkesterone outperformed anabolic steroids. 

As visible in the table pictured, puberal and intact impuberal rodents experienced greater weight gain from turkesterone than from nerabol (Dianabol) and methylandrostenediol (Anabol).

These results are remarkable for several reasons:

1. Dianabol and Anabol are potent anabolic steroids that bodybuilders have used for decades.

2. Anabol and Dianabol generally lead to artificial weight gain due to water retention, unlike turkesterone and ecdysterone. 

3. Turkesterone and ecdysterone stimulated protein synthesis without adverse effects on the endocrine system.

Link:

https://doi.org/10.1007/BF02524596

Study 2

Study type: 

Non-randomised placebo-controlled clinical trial

Purpose:

To measure the effects of ecdysteroids (ecdysterone) on sports performance and body composition.

Interventions:

Ecdysterone supplement and 3 sessions of resistance training per week

Participants:

46 young men with at least 1 year of experience in weight-lifting (bench press, deadlift and squat)

Duration:

10 weeks

Results:

Compared to the placebo group, ecdysterone was correlated with significantly larger increases in muscle mass. The placebo group actually lost muscle mass.

Ecdysterone supplementation was also correlated with a significant increase in bench press and squat performance compared to the placebo group.

Importantly, biomarkers for liver or kidney toxicity did not increase after ecdysterone supplementation.

Year:

2019

Study sponsor:

WADA

Link:

https://doi.org/10.1007/s00204-019-02490-x   

Study 3

Study type: 

Animal & cellular study

Purpose

To elucidate the anabolic potency of ecdysterone (an ecdysteroid similar to turkesterone) in comparison to other known anabolic agents and to support the hypothesis of ERβ mediated action by in-silico modelling.

Dose:

5 mg/kg/day of phytoecdysteroids for 10 days or 10 mg/kg/day of methylandrostenediol (Anabol) or nerobol (Dianabol) for 10 days.

Results:

In the rodent study, ecdysterone exhibited a strong hypertrophic effect on the fibre size of the soleus muscle that was found to be even stronger than dianabol (metandienone), trenbolox (estradienedione), and SARMS1, all administered with the same dose (5 mg/kg for 21 days). 

In the cellular study, ecdysterone (1 µM) induced a significant increase of the diameter of myotubes (a cell found in muscle fibres) comparable to dihydrotestosterone (1 µM) and IGF1 (Insulin-Like Growth Factor, 1.3 nM). 

Conclusion:

The anabolic potency of ecdysterone was comparable or even higher than the anabolic androgenic steroids, SARMs or IGF-1. 

Year

2015

Link:

https://doi.org/10.5604/20831862.1144420 

Study 4

Study type: 

Cellular study

Purpose

To study the mechanism of action of phytoecdysteroids in mammalian tissue.

Results:

In human primary myotubes (cells found in muscle fibres), phytoecdysteroids increased protein synthesis by up to 20%.

Year

2008

Link:

https://doi.org/10.1021/jf073059z 

Study 5

Study type: 

Cellular study

Purpose

To evaluate whether phytoecdysteroids increase protein synthesis.

Results:

20-hydroxyecdysone (ecdysterone), a common phytoecdysteroid in both insects and plants, increased protein synthesis in myotubes (cells found in muscle fibres) by up to 16%.

Year

2010

Link:

https://doi.org/10.1016/j.steroids.2010.03.008 

Products Containing Turkesterone