Magnesium Glycinate vs Bisglycinate: Is There a Difference?

In practice, magnesium glycinate and magnesium bisglycinate are the same thing. 'Bisglycinate' is the more precise chemical name, because each magnesium atom is bound to two glycine molecules. 'Glycinate' is the shorter everyday name. The more useful questions are how much elemental magnesium you get per serving and whether the product is buffered with another form.

Where the two names come from

'Bis' means two. Magnesium bisglycinate describes one magnesium atom bound to two molecules of the amino acid glycine. Because the glycine wraps around the magnesium in a ring-like structure, this is called a chelate, which is why you will also see it sold as chelated magnesium.

Brands and retailers often shorten the name to magnesium glycinate because it is easier to say and easier to search for. Ingredient lists more often use the longer name because it is the precise description of the compound.

So if a product says glycinate on the front and bisglycinate in the ingredients, that is normal. It does not mean the product contains two different ingredients.

Is one stronger than the other?

No. Strength is not about the name. It is about how much elemental magnesium the product delivers in its daily serving, which is the figure shown with a %NRV on a UK label. The adult NRV is 375 mg.

Anhydrous magnesium bisglycinate is about 14% magnesium by weight, calculated from its molecular weight. So 1,000 mg of the compound provides roughly 140 mg of magnesium, whichever name is on the front.

What actually differs between products

Elemental magnesium per serving varies a lot between brands. Compare this figure, not the compound weight.

Buffered or fully reacted. Some products blend magnesium oxide into the glycinate to raise the magnesium per capsule. Labels may call this buffered. A fully reacted product contains only the chelate. Neither label is a claim of quality, but they are different products.

Serving size. One product may state its figure for one capsule and another for three. Check the line that tells you how many capsules make the daily amount.

Other ingredients. The capsule shell, any bulking agents and anti-caking agents appear in the ingredients. If you avoid animal products, check whether the shell is plant-based.

Our post on single-source versus blended magnesium goes into this in more detail.

Read: single-source vs blended magnesium.

Which name should I search for?

Either works. Search engines treat the two as closely related terms, and most UK products appear under both. Online discussions and reviews about glycinate and bisglycinate are almost always about the same compound.

If a product only says 'magnesium' with no form named, look in the ingredients to see which compound is used. A label that names the form is easier to compare.

Glycinate compared with other common forms

Magnesium glycinate is one of several forms sold in the UK. Others you will see include citrate, oxide, malate, taurate and chloride. Each is magnesium bound to a different partner molecule, and the partner changes how much magnesium sits in each gram and how the powder behaves.

The US National Institutes of Health notes that forms which dissolve well in liquid tend to be absorbed more completely than less soluble forms, and that labels there declare elemental magnesium rather than compound weight: NIH ODS. The same principle of comparing elemental amounts applies to UK labels.

Glycinate is often chosen by people who want a single, named form. If you are switching from another form, compare the elemental amount per serving rather than the number of capsules.

How much is sensible?

The NHS says that 400 mg or less a day of magnesium from supplements is unlikely to cause any harm, and that higher doses taken for a short time can cause diarrhoea: NHS. Follow the dose on your product's label and do not combine several magnesium products without checking the total.

People with kidney problems should speak to their GP before taking magnesium. Magnesium can also affect how some medicines are absorbed, including certain antibiotics and osteoporosis medicines, so ask a pharmacist about spacing them.

Hyoomen's figures

Hyoomen Magnesium Glycinate uses magnesium bisglycinate and states 225 mg of elemental magnesium per 3 capsules.

See Hyoomen Magnesium Glycinate.

If you want to know what goes into the capsule itself, see our post on vegan magnesium capsules.

Read: vegan magnesium capsules.

Frequently asked questions

Is bisglycinate better than glycinate?

They are names for the same compound. Compare the elemental magnesium per serving instead.

What does chelated mean?

The magnesium is bound to an amino acid, here glycine, rather than to a mineral salt such as oxide.

What is buffered magnesium glycinate?

A glycinate product with another form, usually magnesium oxide, blended in. The ingredients should say so.

Is magnesium glycinate the same as magnesium glycerophosphate?

No. Glycerophosphate is a different compound with a different name on the label.

Important

This article is general information, not medical advice. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking any medication or under medical supervision, speak to your GP or pharmacist before taking a supplement. Do not exceed the stated recommended daily dose.