Buffered vs Unbuffered Magnesium Glycinate: What's Actually in Your Capsule?

Two tubs can both say "Magnesium Glycinate" on the front and contain quite different things inside. The difference usually comes down to one word you rarely see on the label: buffered.

In this guide we explain what buffered and unbuffered magnesium glycinate are, why the elemental magnesium figure tells you which one you are holding, and what to look for before you buy.

What is magnesium glycinate (bisglycinate)?

Magnesium glycinate is magnesium bound to the amino acid glycine. In the most common form, one magnesium atom is bound to two glycine molecules, which is why you will also see it called magnesium bisglycinate. The two names are used interchangeably on labels.

This bonded structure is known as a chelate. Chelated minerals are popular because the mineral is carried by an amino acid, and many people choose glycinate as their everyday form of magnesium for that reason.

Because glycine is a relatively large molecule, magnesium makes up only a small share of the compound's total weight. That detail is the key to the whole buffered vs unbuffered question.

What is buffered magnesium glycinate?

Buffered magnesium glycinate is magnesium glycinate blended with a cheaper, denser magnesium salt, most often magnesium oxide. Magnesium oxide is around 60% magnesium by weight, so adding even a portion of it pushes up the total magnesium per capsule.

Manufacturers buffer for practical reasons:

• Higher numbers on the label. A buffered powder can show 18–20% elemental magnesium or more, so fewer capsules reach a headline dose.
• Lower cost. Magnesium oxide costs far less than pure glycinate.
• Easier handling. Pure glycinate can be bulky and harder to fill, and blending can help with flow and capsule fill weight.

The catch is that a buffered product is no longer just magnesium glycinate. Part of the magnesium you are paying for comes from magnesium oxide, and labels do not always make that clear.

What is unbuffered magnesium glycinate?

Unbuffered magnesium glycinate is magnesium glycinate on its own, with no magnesium oxide or other magnesium salts blended in. All of the magnesium in the capsule comes from the glycinate form.

You may also see it described as "fully reacted" or "100% chelated". Those terms point in the same direction: the magnesium is bound to glycine rather than mixed in as a separate, cheaper salt.

The trade-off is honest arithmetic. Because glycine is heavy, a pure product carries less magnesium per gram, so the elemental figure on the label is lower. Here, a lower number is a sign of purity.

Elemental magnesium: why 11% signals a pure product

Elemental magnesium is the amount of actual magnesium in a compound, as opposed to the total weight of the compound. It is the figure that matters, and it is the easiest way to spot buffering.

Pure anhydrous magnesium bisglycinate is about 14.1% magnesium by weight, based on its molecular structure. Commercial glycinate usually contains some bound water, which brings it down to around 11–12%. So a genuine, unbuffered magnesium glycinate should sit at roughly 11–14%.

If a product sold as magnesium glycinate claims 18%, 20% or more, the extra magnesium has to come from somewhere. In almost every case that is magnesium oxide.

How to tell if your magnesium glycinate is buffered

You can usually spot a buffered product from the label in under a minute.

1. Check the ingredients list. Magnesium oxide, magnesium citrate or magnesium carbonate listed alongside magnesium glycinate means it is a blend.
2. Work out the elemental percentage. Divide the elemental magnesium per capsule by the weight of magnesium glycinate per capsule. Above about 14%, other magnesium salts are present.
3. Look at the capsule count per dose. A pure glycinate needs more capsules to reach a given amount of magnesium. A suspiciously low capsule count for a high magnesium figure is a clue.
4. Look for the word "unbuffered". Brands selling a pure product usually say so, because it costs more to make.
5. Ask the brand. A reputable supplier will tell you exactly which magnesium salts are in the formula.

Our Unbuffered Magnesium Glycinate

Our Unbuffered Magnesium Glycinate contains magnesium glycinate and nothing blended in to inflate the magnesium figure. Both strengths use the same 11% elemental material, with no magnesium oxide or other magnesium salts, and are made in the UK.

150 mg capsules

• 150 mg magnesium glycinate per capsule
• 11% elemental magnesium, giving 16.5 mg of magnesium per capsule

Shop Unbuffered Magnesium Glycinate 150 mg →

500 mg capsules (coming soon)

• 500 mg magnesium glycinate per capsule
• 11% elemental magnesium, giving 55 mg of magnesium per capsule

Magnesium contributes to a reduction of tiredness and fatigue, normal muscle function and normal functioning of the nervous system.

Frequently asked questions

What is the difference between buffered and unbuffered magnesium glycinate?

Buffered magnesium glycinate is blended with another magnesium salt, usually magnesium oxide, to raise the magnesium content. Unbuffered magnesium glycinate contains magnesium glycinate only.

Is magnesium bisglycinate the same as magnesium glycinate?

Yes. Bisglycinate describes one magnesium atom bound to two glycine molecules, which is the standard form sold as magnesium glycinate.

Why does unbuffered magnesium glycinate have less elemental magnesium?

Glycine is a heavy molecule, so pure magnesium glycinate is only around 11–14% magnesium by weight. Buffered products reach higher figures by adding magnesium oxide, which is about 60% magnesium.

How much magnesium is in a magnesium glycinate capsule?

It depends on the capsule size and the elemental percentage. At 11%, a 150 mg capsule provides 16.5 mg of magnesium and a 500 mg capsule provides 55 mg. Always check the elemental magnesium figure on the label rather than the compound weight.

How can I tell if a magnesium glycinate is buffered?

Check the ingredients for magnesium oxide or other magnesium salts, and divide the elemental magnesium by the glycinate weight. A result above about 14% means other salts are present.

How much magnesium do I need?

The UK and EU Nutrient Reference Value (NRV) for magnesium is 375 mg per day for adults. Food supplements should not be used as a substitute for a varied, balanced diet.