Which Magnesium Is Best? Glycinate, Citrate, Oxide and Malate Compared

The best magnesium is the one that gives you a useful dose of the mineral without upsetting your stomach, and for most people that means glycinate for daily use, citrate if constipation is part of why you want it, and oxide for nothing except a cheap laxative. The forms differ in three things: how much magnesium they carry by weight, how well that magnesium is absorbed, and how much they loosen the bowels.^{1, 2} They do not differ in what the magnesium does once it is in you, so claims that one form is "for sleep", another "for anxiety" and a third "for the brain" are marketing built on the compound the magnesium is attached to, not on trials. The table below gives the elemental content of each common form so you can compare labels, and the rest of the page answers the questions people actually search: which for sleep, cramps, tiredness, women, migraine, and whether you can mix them.

• Glycinate (bisglycinate): about 10 to 14% magnesium; well absorbed; gentlest on the bowels; the daily-use choice
• Citrate: about 11 to 16%; well absorbed; laxative at useful doses; the constipation choice
• Oxide: about 60%; poorly absorbed; most laxative; cheap
• Malate: about 15%; well tolerated; a glycinate alternative
• Taurate, threonate, orotate, chloride, sulphate, sprays: niche, thin human evidence, or not absorbed through skin

What "best" can and cannot mean

Magnesium is one element. Whatever it is bound to, the magnesium ion that reaches your blood is identical and does the same things: it contributes to normal muscle function, normal functioning of the nervous system, normal energy-yielding metabolism, normal psychological function, the maintenance of normal bones and a reduction of tiredness and fatigue.³ So "best" can only mean best absorbed, best tolerated or best value, and the answer changes with the person. A form that gives you diarrhoea is not best for you however well it absorbs in a study. The compound it is bound to, glycine, citrate, malate, taurine, matters for tolerability and for how much of the capsule is magnesium; it does not add a separate benefit at the doses involved. Our hub on what magnesium is good for covers the mineral itself.

The forms compared

Elemental percentages are from the chemistry of each compound; real products vary with hydration and fillers, so the nutrition panel's "magnesium ... mg (...% NRV)" is the number to trust. Absorption studies are few and small. The best known found citrate more bioavailable than oxide and than an amino-acid chelate over 60 days; a 2024 study compared several forms and again found oxide the poorest.^{1, 2} The differences between the well-absorbed forms are smaller than the marketing suggests, and the dose and your tolerance matter more than the form.

Is magnesium glycinate the same as bisglycinate?

Yes. Each magnesium ion is bound to two glycine molecules, so bisglycinate is the precise name and glycinate the common one. The thing to check is whether the product is "buffered", which means magnesium oxide has been added; the label will list both. What is magnesium glycinate covers the form in full.

Which magnesium is best for sleep?

None is proven for sleep, and no UK product may claim it. The small trials that exist used magnesium oxide or unspecified forms in older adults who were short of magnesium and found a modest effect on falling asleep.⁴ Glycinate is recommended online for sleep because it is the form you can take at night without being up with cramps or the bathroom, which is a tolerability argument, not a sleep argument. If you want to try magnesium for sleep, glycinate or malate at 100 to 300 mg of elemental magnesium in the evening for four weeks is the sensible version; does magnesium help you sleep sets out what to expect.

Which magnesium is best for cramps and restless legs?

Any well-absorbed form, if low magnesium is the cause, which it often is not. Night cramps have many causes and the trials of magnesium for them are mixed, with the clearest signal in pregnancy and in people who were deficient; for restless legs, low iron is the better-established cause and a ferritin test is the first step.⁵ If you try magnesium, glycinate or citrate at a modest dose for a month is reasonable, and if nothing changes, the cause lies elsewhere. There is no authorised claim for either.

Which magnesium is best for tiredness?

Any form that corrects a shortfall. Magnesium contributes to a reduction of tiredness and fatigue, which is an authorised claim describing what happens when a deficient person gets enough; it is not an energy supplement for people who are not short. Glycinate or malate for daily use. Tiredness that persists deserves a GP blood test for iron, B12, folate, vitamin D and thyroid before any mineral.

Which magnesium is best for women?

The same forms as for anyone. Women's reference intake is 270 mg a day against 300 mg for men, pregnancy and breastfeeding add little in UK guidance, and the questions women ask about magnesium, period pain, PMS, menopause symptoms and bone health, have no authorised claims and mixed evidence. Magnesium contributes to the maintenance of normal bones, which matters after the menopause as part of a diet with enough calcium, protein and vitamin D. For period pain, small trials of magnesium exist and a GP or pharmacist can advise on evidence-based options; for menopause symptoms, which menopause supplements have evidence reviews what the trials show.

Which magnesium is best for migraine, anxiety, blood pressure or tremor?

These are medical questions, and none has an authorised claim. Magnesium is studied in migraine prevention and some neurologists recommend it; it is sometimes used in hospital for blood pressure emergencies in pregnancy; and low magnesium can contribute to tremor and palpitations. In every case the person to ask is your GP or specialist, who may suggest magnesium or may not, and the form matters less than the dose and your kidneys. Anxiety and mood are covered in the signs of low magnesium, with the evidence described honestly.

Can you take magnesium citrate and glycinate together?

Yes, and many blends do. Add the elemental figures from both and keep the total at or below the UK supplement guidance of 400 mg a day; expect the citrate share to decide the bowel effect.⁶ Taking two forms does not absorb better than one; it is a way to balance tolerability against cost.

What is the downside of magnesium citrate?

Loose stools at the doses needed to top up intake, which is why it is sold as a laxative as well as a supplement. Taken for constipation that is useful; taken for daily top-up it is often the reason people conclude "magnesium doesn't agree with me". It is well absorbed and inexpensive, and a good choice when constipation and low intake go together.

How to choose

Decide the elemental dose you want, usually 100 to 300 mg a day to close the gap between food and the reference intake; which foods contain magnesium shows how far food gets you. Pick glycinate or malate unless constipation is part of the picture, in which case citrate. Avoid oxide for topping up, avoid buffered glycinate if you want the gentle form, and treat sprays and bath flakes as pleasant rather than nutritional. Check the nutrition panel for the elemental figure, not the headline. Stay within 400 mg a day and check is it OK to take magnesium every day for who should not. Wellgard's Mag 1200 magnesium bisglycinate is a pure, unbuffered glycinate with the elemental magnesium stated per serving; magnesium contributes to normal muscle function, normal functioning of the nervous system and a reduction of tiredness and fatigue.

What we don't know

• Head-to-head absorption of glycinate against citrate in healthy adults. Studies are small and use different measures.^{1, 2}
• Whether threonate reaches the brain in people at supplement doses. The evidence is in rodents.
• Whether any form helps sleep, cramps or mood in people with normal magnesium status. No authorised claim; trials mixed.^{4, 5}

Frequently asked questions

What is the most effective magnesium to take?

Glycinate or citrate, both well absorbed; glycinate if you want the gentlest on the bowels, citrate if constipation is part of the picture. Oxide is poorly absorbed.^{1, 2}

Which is better for sleep, magnesium citrate or glycinate?

Neither has sleep evidence of its own. Glycinate is the practical night-time choice because it does not loosen the bowels; the sleep trials are small and in deficient older adults.⁴

Which magnesium is best for cramps?

Any well-absorbed form, if low magnesium is the cause. For restless legs, check iron first. There is no authorised claim for either.⁵

Can I take magnesium citrate and glycinate together?

Yes. Add the elemental doses and stay at or below 400 mg a day from supplements.⁶

Is magnesium oxide useless?

As a daily top-up, nearly: little is absorbed and most of its effect is laxative. As an occasional laxative it works. Forum claims that it is "4% absorbed" overstate the case, but it is the poorest form.

Sources

1. Walker AF, et al. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnesium Research, 2003. PubMed 14596323.
2. Pajuelo D, et al. Comparative clinical study on magnesium absorption and side effects after oral intake of microencapsulated magnesium and other forms. Nutrients, 2024. PubMed 39770988.
3. NHS. Vitamins and minerals: others, including magnesium. nhs.uk; Great Britain nutrition and health claims register.
4. Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis. BMC Complementary Medicine and Therapies, 2021. PubMed 33865376.
5. Liu J, et al. Effect of oral magnesium supplementation for relieving leg cramps during pregnancy: a meta-analysis of randomized controlled trials. Taiwanese Journal of Obstetrics and Gynecology, 2021. PubMed 34247796.
6. Costello R, et al. Perspective: call for re-evaluation of the tolerable upper intake level for magnesium supplementation in adults. Advances in Nutrition, 2023. PubMed 37487817.

This article is general information, not medical advice. Migraine, palpitations, tremor and blood pressure are medical matters; people with kidney disease should not take magnesium supplements without medical advice.