The supplement industry is lying to you.

Buffering is when a brand blends a cheap, highly concentrated form of magnesium — usually magnesium oxide — into a product sold as "magnesium glycinate." The front of the bottle still says glycinate, but a chunk of the magnesium inside isn't glycinate at all. It's a way to make the number on the label look bigger than the glycinate alone could ever produce.

Two reasons, both about money. Oxide is one of the cheapest forms of magnesium you can buy, so it cuts ingredient costs. And because oxide is around 60% magnesium by weight, a small amount inflates the elemental figure on the label — letting a brand print a big number from just two capsules instead of an honest one from four. Bigger number, smaller cost, same shelf price.

Magnesium can't sit in a capsule on its own — it has to be bonded to a carrier. Glycinate bonds it to glycine, which your body absorbs well (around 40–50%) and which has a calming effect, but it's bulky, so only about 14% of the compound is actual magnesium. Oxide is the opposite: roughly 60% magnesium by weight, but your body absorbs only about 4% of it. One looks impressive on paper; the other actually gets into you.

Because the label number is elemental magnesium — how much is in the capsule, not how much you absorb. A big number from oxide can leave you absorbing less than a smaller number from glycinate. A small amount you absorb beats a big amount you don't. The form is the whole story; the number on its own tells you very little.

Run one quick calculation, then check for the giveaways:

• The 14% rule. Take the compound weight on the label (e.g. "2,000mg magnesium bisglycinate") and multiply by 0.14. That's the maximum elemental magnesium pure glycinate can provide. If the label claims more, the extra is coming from something that isn't glycinate. Example: 2,000mg × 14% = 280mg max — so any product claiming 400mg "from glycinate" doesn't add up.
• The word "buffered" anywhere on the label or listing. It sounds technical; it means diluted with oxide.
• A big number from a small serving. Two capsules hold roughly 2,000mg of powder, so ~280mg elemental is the ceiling from glycinate. A 2-capsule product claiming 300mg+ "from glycinate" can't be pure.
• No compound weight shown. If it only says "Magnesium 375mg (as bisglycinate)" without the bisglycinate weight, you can't run the maths — which is often the point.
• Blend language like "complex," "3-in-1," or "glycinate blend." Multiple forms muddy the maths and give oxide a place to hide.

You can exceed 14% elemental magnesium — but not with glycinate. The 14% ceiling comes straight from atomic weights: magnesium is 24, two glycine molecules are about 148, so fully-reacted magnesium bisglycinate is 24 ÷ 172 = 14.1%. No manufacturing process changes that, because no process makes magnesium heavier or glycine lighter. Even a 1:1 mono-glycinate only reaches about 21%. So if a product claims, say, 29% elemental, roughly a third of that magnesium isn't bonded to glycine — it's bonded to something more concentrated. "Chelation technology" is a real thing, but it stabilises the bond; it doesn't break the laws of chemistry. The fair question to ask any brand making that claim: if the magnesium above 14% isn't glycine, what is it bonded to?

Largely, yes — which is the frustrating part. Magnesium oxide is a permitted source, so using it isn't illegal in itself. There's no rule forcing a brand to write the word "buffered" on the pack, and the label only has to declare the total amount of magnesium, not split it by form. What a brand can't legally do is leave oxide off the ingredients list if it's in the product, or front a label as "glycinate" in a way that misleads you about what's actually inside. The bigger issue is enforcement: almost nobody tests finished products on the shelf to check the label matches the capsule — so the maths is often your only protection.

It isn't poison, and it has its uses — it's commonly used as a laxative, precisely because so little is absorbed that it stays in the gut and draws in water. The problem is paying a premium for "glycinate" and unknowingly getting oxide your body can barely use, plus the digestive upset that often comes with it. Oxide isn't dangerous; it's just the wrong tool if you're buying magnesium to absorb it.

Because that's what an honest dose of pure glycinate actually takes. Glycine is bulky, so to give you a proper amount of absorbable magnesium without buffering, you genuinely need four capsules — there's no shortcut. Brands that hit a big number in two capsules are almost always making up the difference with oxide. We'd rather give you four honest capsules than two padded ones.

You get 338mg of elemental magnesium per four-capsule serving, all of it from pure magnesium glycinate — and because it's glycinate, it sits comfortably under the 14% ceiling we hold everyone else to. We don't inflate it. The number on our label is the number your body can actually work with, and you can confirm it against the test for your exact batch.

Fair challenge, and the honest answer is: don't take our word for it. Every batch we make is sent to an independent, accredited lab before it ships, and we publish the result. The maths on our label obeys the same 14% rule we use to catch everyone else — if we were buffering, you'd see it in the numbers, and you'd see it in the test. The whole point of the brand is that there's nowhere for us to hide it either.

It means every single production run is tested by an outside ISO 17025-accredited laboratory — not us, not a one-off test from years ago, but the actual batch in your hand. If a batch doesn't pass, it doesn't ship. Most brands rely on a single historic certificate or their supplier's word; we test each batch and put the results where you can read them.

There's a QR code on your bottle. Scan it and you'll see the third-party test for your specific batch — the form, the amount, the lab. No login, nothing hidden. If what you're holding doesn't match what the label promised, you'll know.

It's one of the gentlest forms of magnesium for exactly the reason it's worth paying for — it's well absorbed, so less of it lingers in the gut. The digestive upset people associate with magnesium usually comes from poorly absorbed forms like oxide, which is why buffered "glycinate" can still leave you uncomfortable. Pure glycinate is typically much easier on the stomach.

Four capsules a day, with water, at any time that suits you — with or without food. Many people prefer the evening because glycine has a calming effect, but there's no wrong time. Consistency matters more than timing.

Magnesium is involved in hundreds of processes in the body, and most people in the UK don't get enough from diet alone. Authorised health claims for magnesium include contributing to normal muscle function, to the reduction of tiredness and fatigue, to normal functioning of the nervous system, to normal psychological function, and to the maintenance of normal bones and teeth. It's a foundational mineral — which is exactly why it's worth getting a form you can absorb.