Magnesium glycinate for sleep and stress: popular, cheap, and weakly supported

Magnesium glycinate is magnesium bound to glycine, an amino acid, and it is sold as a gentler, better-absorbed form for sleep and calm. With 110,000 searches a month it is level with the Oura ring as the most searched item in this index.

Sleep

• A 2021 meta-analysis of older adults with insomnia found magnesium added about 16 minutes of sleep a night, but the difference was not statistically significant. All the trials were at moderate to high risk of bias. The authors added that, because magnesium is cheap and widely available, the evidence may still support trying it.
• A 2026 review of randomised trials in adults was firmer: the evidence does not support oral magnesium as a routine treatment for insomnia. Some people may get modest benefits on some measures, but the findings were inconsistent and the certainty low or very low.

Anxiety and depression

A 2017 review in Nutrients found the evidence suggestive of a benefit on anxiety in people prone to it, but of poor quality. A 2023 meta-analysis in Frontiers in Psychiatry found depression scores fell in adults with a diagnosed depressive disorder who took magnesium.

Restless legs and cramps

A 2019 review could not conclude whether magnesium helps restless legs, and a 2021 meta-analysis found it did not relieve leg cramps in pregnancy.

Yes, but

None of these reviews tested magnesium glycinate specifically; the trials used a range of forms. Claims that glycinate works better for sleep are about absorption and gut comfort, not about trial results. Very high doses of magnesium can cause diarrhoea and are risky with kidney disease.

When to talk to your GP

If you have kidney disease, take antibiotics, bisphosphonates or other regular medicines, or if poor sleep or low mood lasts more than a few weeks.

Sources

1. Magnesium supplementation for sleep in adults: a systematic review of randomized controlled trials, J Diet Suppl, 2026
2. Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis, BMC Complement Med Ther, 2021
3. The effects of magnesium supplementation on subjective anxiety and stress: a systematic review, Nutrients, 2017
4. Magnesium supplementation beneficially affects depression in adults with depressive disorder, Front Psychiatry, 2023
5. Magnesium supplementation for restless legs syndrome and periodic limb movement disorder, Sleep Med Rev, 2019

Checked 3 October 2026. Spotted something out of date? Tell us via the about page.

General information, not medical advice. Check with your GP first, especially if you are pregnant, have a heart condition or take medication.