Comparison
Magnesium glycinate vs citrate vs bisglycinate
Magnesium glycinate and magnesium bisglycinate are the same thing: magnesium bound to the amino acid glycine. Magnesium citrate is magnesium bound to citric acid. In small studies, citrate was absorbed better than magnesium oxide, the form with the most magnesium by weight. We found no human trial that compares glycinate with citrate, so the claim that glycinate is gentler on the stomach is not proven. This is information, not medical advice.
At a glance
| Form | What it is | What the studies show | What to check |
|---|---|---|---|
| Glycinate (bisglycinate) | Magnesium bound to the amino acid glycine. Glycinate and bisglycinate are two names for the same compound. | Often sold as gentle on the stomach. We found no human trial comparing it with citrate, so treat that as a sales claim, not a proven difference. | Compare the elemental magnesium per serving, not the weight of the whole compound. |
| Citrate | Magnesium bound to citric acid. | In a small 1990 study it dissolved better than oxide and more of it was absorbed. | Of the three, it has the most direct comparison with oxide. |
| Oxide | Magnesium combined with oxygen. It holds a lot of magnesium by weight. | Poorly absorbed in two small studies: about 4% was absorbed in one of them. | A high mg figure on the label does not mean more magnesium gets into your body. |
Glycinate and bisglycinate: the same form
Glycinate and bisglycinate describe the same compound: magnesium bound to the amino acid glycine. PubChem, the US government chemistry database, lists magnesium bisglycinate as another name for magnesium glycinate. Labels use either name.
Where the table comes from
We read these sources on 1 November 2026.
Citrate and oxide: a 1990 study in the Journal of the American College of Nutrition found magnesium citrate dissolved better than magnesium oxide, and more of it was absorbed, in healthy volunteers. A 2001 study in Magnesium Research found only about 4% of magnesium oxide was absorbed, against more for the chloride, lactate and aspartate forms. Both studies were small.
Glycinate: we searched PubMed and found no human trial that compares it with citrate for absorption or stomach upset.
How much: the NHS page on magnesium says women aged 19 to 64 need 270mg a day and should be able to get it from a varied diet. It says 400mg or less a day from supplements is unlikely to cause harm, and that more than 400mg for a short time can cause diarrhoea. This applies whichever form you take.
How we compared
Our methodology is simple and disclosed. We describe each form factually on what it is, how well tolerated and absorbed it tends to be, and who it suits, without claiming any form treats a condition. We do not rank by affiliate commission. Where a buying link is not yet live, the link is marked as pending rather than guessed.
Named UK brands by form
For the full background read our guide to magnesium for women, see the best magnesium for women roundup, or the practical question of when to take magnesium. It comes up most through perimenopause and the senior years.
Frequently asked questions
Is glycinate the same as bisglycinate?
Yes. Both names mean magnesium bound to the amino acid glycine, and labels use either one.
Which is gentler on the stomach, glycinate or citrate?
Glycinate is often sold as the gentler one, but we found no human trial that compares the two. The NHS says more than 400mg of magnesium a day can cause diarrhoea, whatever the form. Ask your pharmacist if you are unsure.
Is citrate better absorbed than oxide?
In small studies, yes. Citrate was absorbed better than oxide in a 1990 study, and only about 4% of oxide was absorbed in a 2001 study (both linked above). None of these forms is a treatment for any condition.
Which magnesium form should I choose?
There is no single right answer. Read the label for the elemental magnesium per serving, not the weight of the whole compound, and keep supplements to 400mg a day or less, as the NHS advises. If you take other medication or have kidney problems, speak to your GP or pharmacist first.
This is information, not medical advice, and is not a substitute for a registered clinician. Always read product labels and speak to your GP or pharmacist before starting a supplement.
We sell this in our store
Magnesium Glycinate
Her Vitals' own magnesium uses the glycinate (bisglycinate) form discussed above: 275 mg of elemental magnesium from 2,500 mg of magnesium glycinate per three-capsule serving, within the NHS's 400 mg supplemental guidance.
Sold by us directly from our own Shopify store, disclosed here as our own product like any other. This is a direct sale by us. It does not win our roundups or calculators automatically. Check our price against any other product with the cost-per-effective-dose calculator.
Editor, Her Vitals
Oliver leads Her Vitals's editorial coverage of women's life-stage health and supplements. He curates and reviews existing branded products across trying to conceive, pregnancy, postnatal, perimenopause, menopause and the senior years, weighing what the evidence supports against guidance from bodies such as EFSA, the NHS and NICE, and is clear that the content is information rather than medical advice.
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