Why it matters

60% of UK adults don't get enough magnesium.

Magnesium is involved in over 300 enzymatic processes in the body — from energy production to nerve function to cardiovascular health. But most of us aren't eating the vegetables, seeds and whole grains that used to supply it. So we reach for a supplement. The problem is what happens next.

  • Sleep & relaxation
  • Muscle cramps
  • Heart rhythm
  • Bone health
  • Energy production
  • Nervous system
  • Blood sugar
  • Stress response
60%
of UK adults have a suboptimal magnesium intake
300+
enzymatic reactions in the body require magnesium
The absorption problem

The form matters more than the number.

Not all magnesium is equal. The body can only use what it can actually absorb — and absorption varies wildly between forms. Here's the difference between the two most common forms on UK shelves.

Cheap form

Magnesium Oxide

The form hidden inside most “premium” blends.

Elemental magnesium on label63%
Actually absorbed by the body~4%
Looks impressive on the label. Prints a big number on the front of the bottle. But your body flushes most of it out. It's the cheapest magnesium you can buy.
Our form

Magnesium Glycinate

100% pure. No oxide mixed in.

Elemental magnesium on label13%
Actually absorbed by the body40–50%
Smaller number on the label. Ten times more of it makes it into your system. Also gentler on the stomach than most other forms.

Absorption rates based on published bioavailability studies (e.g. Walker et al., Magnes Res 2003).

Us vs Them

What's on the label. And what's really in the bottle.

We ran the maths on the top-selling magnesium supplement in the UK. Their elemental claim is mathematically impossible from the ingredients they list — the only way to make the numbers work is by adding cheap magnesium oxide that never made it onto the label. Here's the maths.

The top UK brand
384MG ELEMENTAL CLAIM
MISLEADING
Generic UK magnesium supplement bottle
2-capsule serving

Glycinate + malate + citrate blend (per label)

1Maths from the declared blend Doesn't add up
1,000mg glycinate × 13%= 130mg
400mg malate × 15%= 60mg
400mg citrate × 16%= 64mg
What the label adds up to= 254mg
Missing to hit their claim= 130mg
2Reconciled with hidden oxide Buffered
Declared blend (above)= 254mg
~217mg undeclared oxide × 60%= 130mg
Real total to hit 384mg claim= 384mg
34% of the magnesium in this bottle is from a cheap form they didn't declare — the form with ~4% absorption. The premium ingredients on the label are doing less than half the work.
vs
NF Supplements
338MG ELEMENTAL ACTUAL
VERIFIED
NF Magnesium Glycinate bottle
4-capsule serving · 650mg per cap

100% pure magnesium glycinate. Nothing else.

1Maths from the declared blend Adds up
2,600mg glycinate × 13%= 338mg
No malate= 0mg
No citrate= 0mg
What the label adds up to= 338mg
Missing to hit our claim= 0mg
2Reconciled with hidden oxide Not needed
Declared blend (above)= 338mg
Undeclared oxide= 0mg
Eurofins-verified actual= 338mg
0% gap. 100% pure magnesium glycinate, third-party verified by Eurofins. Every milligram in the bottle is on the label. Nothing buffered. Nothing hidden.

"If it's in the bottle, it's on the label."

Pure glycinate · Zero hidden fillers · Third-party verified
NF Magnesium Glycinate bottle with QR code
Close-up of the QR code printed on the NF Magnesium Glycinate bottle Zoom
Scan this
Independent proof

Scan your bottle. See your batch.

Every bottle has a QR code on the front. Scan it when your order arrives and you'll see the actual Eurofins lab report for your exact batch — not a generic certificate, not last year's test, not a marketing PDF. Your batch. Tested before it shipped.

1

Your bottle ships with a QR code

Printed on the front label. Every bottle. Every batch. No exceptions.

2

Open your phone camera. Scan it.

Takes you straight to the Eurofins certificate — ISO 17025:2017 accredited, ICP-MS method. No login, no paywall.

3

Verify the label matches the lab

338mg elemental magnesium. If the result doesn't match what's on the bottle, it never left our facility.

Side by side

The full comparison.

Six honest comparisons. Form, dose, absorption, tolerance, testing, manufacturing — all in one place, with nothing hidden in the small print.

What's Actually Inside
NF Glycinate
"Buffered" Brands
Magnesium form
100% glycinate
Glycinate + hidden oxide
Real elemental Mg
338mg, honest
384mg Claimed
254mg Without oxide
Absorption rate
~45% absorbed
~4% (oxide portion)
Easy on your stomach
Gentle, no upset
Oxide = laxative effect
Lab tested every batch
Yes, every single batch
Once, then never again
Made in
Our own Oxford facility
Mystery contract factory

What you see. Is what you get.

Every ingredient. On the label.
0mg
Undeclared fillers
~130mg
Hidden oxide in their bottle

Customer Reviews

Based on 31 reviews
74%
(23)
23%
(7)
3%
(1)
0%
(0)
0%
(0)
R
RC
Migraine frequency down

Ive had chronic migraines for over 15 years. tried loads of preventatives, some work some dont. neurologist mentioned magnesium glycinate ages ago but i never got round to it properly. ordered this after seeing the detailed info on dosing. been on it nearly 3 weeks. ive had 2 migraines in that time vs my usual 5 or 6. too early to call it conclusive but the trend is good. the dose is what matters with magnesium for migraine apparently, most brands underdose massively. NF get it right. sleep is also noticeably better which helps in itself.

R
Rachel
Nice one

works for sleep. recommend

J
J.W.
Great for shift workers

Im a nurse on a rotating shift pattern and my sleep has always been chaos. magnesium glycinate on the advice of a colleague. genuinely helping me get to sleep when my body clock is all over the place. 2 weeks in. i think the combination of calming the nervous system and helping muscle relaxation is whats working. good product.

E
Emma
Didnt do much for me

Ive given it 18 days and honestly havent noticed a big difference. sleep about the same, general mood about the same. maybe im not deficient? not knocking the product as it seems well made and the brand info is good, just didnt do what i hoped for me personally. will finish the bottle

C
Connor
Good

Works. 3 caps is a lot tho.

Common questions

Everything you're actually wondering.

We've answered every question we've ever been asked about magnesium — the science, the maths, the sneaky label tricks, the dosing, and everything in between. If we missed one, email us and we'll add it.

About the product

Because we're only using pure magnesium glycinate, which is naturally 13% elemental magnesium. That's a chemistry fact, not a formulation choice — glycinate molecules are big, and most of the weight is the glycine (the amino acid), not the magnesium itself.

The brands showing 384mg, 400mg, 500mg+ of elemental magnesium "from glycinate" on a 2-capsule serving are either mathematically wrong or mixing in cheap magnesium oxide (63% elemental magnesium) without declaring it on the label. We checked the maths on the top sellers — in every case, the number on the front of the bottle can't be reached from the ingredients listed on the back.

We'd rather show an honest number than a misleading one. Our 338mg is verified by Eurofins, comes from pure glycinate, and every milligram is on the label.

Pure magnesium bisglycinate (2,600mg per 4-capsule serving, providing 338mg elemental magnesium), a rice-based flow agent at trace levels to keep the powder flowing through the capsule-filling machine, and a plant-based HPMC capsule shell. Every ingredient listed on the label is in the bottle. Every ingredient in the bottle is on the label.

No magnesium oxide. No magnesium carbonate. No "proprietary blends" that let us hide cheaper fillers behind a single umbrella ingredient. No titanium dioxide. No artificial colours. No lactose, no gluten, no nuts, no soy.

Because magnesium glycinate is bulky. Each capsule physically holds about 650mg of powder, so to fit a meaningful elemental dose of pure glycinate (without the oxide shortcut other brands use), you need four capsules per serving.

Most brands squeeze it into 2 capsules by mixing in oxide, which is denser and has a higher elemental percentage but terrible absorption. We made the choice to prioritise form over capsule count.

The science

Magnesium is involved in over 300 enzymatic reactions — it's one of the most essential minerals in human biology. The main functions include:

  • Muscle & nerve function — regulates muscle contraction and nerve signalling.
  • Sleep & relaxation — modulates GABA and melatonin production.
  • Energy production — every molecule of ATP needs magnesium to function.
  • Cardiovascular health — supports normal heart rhythm and healthy blood pressure.
  • Bone health — ~60% of the body's magnesium is stored in bone.
  • Stress response — depleted by chronic stress; low magnesium makes stress response worse.

Three reasons:

  • Absorption. Glycinate is chelated — bonded to the amino acid glycine — which the gut absorbs through amino-acid pathways. 40–50% bioavailability vs ~4% for oxide.
  • Tolerance. Doesn't cause the laxative effect that other forms (especially citrate and oxide) are known for.
  • Calming. The glycine half is itself a precursor to GABA. Some people report better sleep from glycinate specifically.

Nothing's "wrong" with it — it's just the worst-absorbed form of magnesium commonly sold. Published studies put its absorption at around 4% of the elemental dose. That means if a pill contains 300mg of elemental magnesium from oxide, your body absorbs roughly 12mg.

The reason brands use it anyway: oxide is the cheapest form to produce, and it has the highest elemental percentage by weight (~63%). That combination lets brands print a big number on the front of the bottle at a tiny ingredient cost.

"Buffered" is an industry euphemism. It means the brand has mixed in cheap magnesium oxide with the more premium form (like glycinate) to inflate the elemental magnesium number on the label while keeping ingredient costs down.

If you see the word "buffered" anywhere on a magnesium product — or if you do the maths on the ingredient list and the elemental number doesn't add up — there's almost certainly oxide in there. That's the trick.

Taking it

Most people take it in the evening, 30–60 minutes before bed, because magnesium has a mild calming effect. Glycinate is particularly good for this because of the glycine component.

Consistency matters more than timing. Whatever time makes it easiest for you to remember is the right time.

Yes, and it slightly improves total uptake. Glycinate is gentle enough to take on an empty stomach without issues.

Avoid taking magnesium at the exact same time as very high-calcium foods or calcium supplements, because they compete for the same absorption pathways.

Magnesium isn't a stimulant — it won't give you an immediate hit like caffeine. It builds up in tissues over time.

Most people report the clearest changes (sleep quality, muscle tension, a calmer baseline) somewhere between 2 and 4 weeks of consistent daily use.

From supplements alone, excess elemental magnesium typically causes loose stools well before anything more serious — your body flushes it out. The NHS-recognised upper limit for supplemental magnesium in healthy adults is 400mg of elemental magnesium per day.

Our serving is 338mg elemental, leaving comfortable headroom under the 400mg upper limit. If you have kidney problems, are pregnant, or take prescription medication, check with your doctor before supplementing.

Generally yes. Magnesium plays well with most supplements including B vitamins, vitamin D, zinc, and omega-3s. Common combinations like magnesium + vitamin D3 + K2 are actively helpful.

Watch out for: high-dose calcium and high-dose iron compete with magnesium for absorption. If you're taking more than 500mg of either, space them at least an hour apart from your magnesium.

Testing & trust

Yes — scan the QR code on the front of your bottle. It links directly to the Eurofins Certificate of Analysis for the exact batch you're holding. No paywall, no login, no chasing us for a PDF.

Each report shows: batch number, elemental magnesium content, heavy metals testing (lead, arsenic, cadmium, mercury), and microbial testing. If any result fails, the batch doesn't leave our facility.

ISO 17025:2017 is the international standard for testing and calibration laboratories. An ISO 17025-accredited lab has been independently audited for technical competence — their methods, equipment, staff, and quality control.

In practice, it means their results are recognised as accurate and defensible in legal and regulatory contexts. A non-accredited lab's result is a guess with a letterhead.

Eurofins is one of the largest and most respected testing networks in the world — they're used by regulators, pharma companies, and food safety authorities across Europe. They're not cheap, and they don't negotiate on results.

We could save money by using a smaller, less-rigorous lab. We don't, because the whole point of third-party testing is that the lab has no incentive to tell us what we want to hear.

Three things:

  • Form. We use only magnesium glycinate. No oxide hiding in the formula.
  • Testing. Every batch tested by Eurofins before it ships. Most brands test once, if ever.
  • Manufacturing. We make it ourselves at our Oxford GMP facility — we're not outsourcing to a contract facility we've never visited.
Ordering & delivery

Subscribe and save up to 40% on every order. Your bottles ship automatically on your chosen frequency (monthly or every 3 months). You can pause, skip, change frequency, or cancel anytime from your account dashboard — no phone calls, no retention guilt-trips.

If you're not happy with your order for any reason, we'll refund you — no questions, no hoops. We'd rather lose a sale than keep someone on a supplement they don't believe in.

We ship across the UK with free tracked delivery on subscriptions (2–4 working days). Standard UK delivery on one-time orders is £3.99. We also ship to the EU and US from dedicated facilities — delivery times and pricing shown at checkout.

NF Magnesium Glycinate
£59.97 £29.99 for 3 months