Awaiting clinical review. This entry is sourced but has not yet been signed off by a pharmacist or clinician.

Magnesium bisglycinate (mineral chelate)

Magnesium glycinate

Magnesium glycinate has limited evidence for sleep and anxiety: the one placebo-controlled trial of the glycinate form found a small improvement in insomnia scores after four weeks, and the wider magnesium research is low quality. It is generally well tolerated, but supplemental magnesium can cause loose stools, and people with severely reduced kidney function should ask a doctor first. Nobody has shown that glycinate works better than other magnesium forms for either use.

Written by

Healthy and Herbal editorial team

Updated

29 September 2026

White capsules in a small dish with a glass of water

At a glance

Last reviewed 29 September 2026

Evidence

Limited

Best for

Poor sleep

Typical form & use

Bisglycinate, 250 mg elemental Mg

Onset

4+ weeks

Safety

Loose stools above about 250–350 mg supplemental Mg. No interactions in our data.

Check with your medications →

What it's used for

Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.

Use	Evidence	What the research shows
Poor sleep / insomnia symptoms	Limited	In one 4-week placebo-controlled trial of 153 adults with self-reported poor sleep, 250 mg elemental magnesium as bisglycinate cut Insomnia Severity Index scores by 3.9 points versus 2.3 on placebo (p = 0.049; effect size small, d = 0.2), using self-reported outcomes only. A meta-analysis in older adults (three trials, 151 people, oxide or citrate rather than glycinate) found about 17 minutes shorter time to fall asleep, but all trials had moderate-to-high risk of bias and the evidence was graded low to very low.^1,2
Anxiety and stress	Limited	A systematic review of 18 studies (doses 46.4–600 mg, mostly lactate and oxide, often combined with vitamin B6 or herbs) found suggestive benefit in people prone to anxiety, but the authors called the quality of the evidence poor. A later review of 15 trials found improvement in at least one sleep or anxiety measure in most, but the studies were small and varied widely. None of this is specific to glycinate.^3,4

How much

Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.

Studied range (glycinate)

250 mg elemental Mg daily¹

The only glycinate sleep trial used 250 mg elemental magnesium (with about 1.5 g glycine) for 4 weeks. Product labels often quote the whole compound weight, so check the elemental figure.

Studied range (magnesium generally)

About 46–730 mg elemental Mg daily^2,3

Sleep trials in older adults used 320–729 mg daily as oxide or citrate; anxiety trials ranged from 46.4 to 600 mg. These are other magnesium forms.

Upper limit (EU)

250 mg supplemental Mg per day⁵

The EU Scientific Committee on Food set this from mild diarrhoea appearing at about 360–365 mg. It excludes magnesium in food, and the opinion names salts such as chloride, sulphate, aspartate, lactate and oxide; glycinate is not named.

Upper limit (US)

350 mg supplemental Mg per day⁶

Set by the US Institute of Medicine in 1997 with diarrhoea as the limiting effect; a 2023 review argues it is too conservative, but it remains the published figure.

Timing · The glycinate sleep trial ran daily for 4 weeks; the sources do not say what time of day gave the best results.With food? · One review of the upper-limit evidence suggests splitting doses through the day and taking them with food to reduce diarrhoea; the glycinate trial did not test this.How long to trial · The glycinate trial judged sleep at 4 weeks, so give it about that long. If nothing has changed, it is unlikely to help you.

How people take it

Capsule or tablet (bisglycinate)250 mg elemental MgThe form and dose used in the one glycinate sleep trial. Check the elemental magnesium per serving, not the compound weight.

Powder (bisglycinate)Same elemental doseNo trial data on powders specifically; the dose logic is the same.

Safety

Who should avoid

Severe kidney impairment — magnesium can build up (hypermagnesaemia)
Pregnancy and breastfeeding — ask a clinician about dose first
Children — the EU sets no upper limit for ages 1–3 and 250 mg only from age 4
On regular medicines — check with a pharmacist first

Known interactions

No interactions in our data. Absence of a flag is not clearance.

Questions people ask

Does magnesium glycinate help you sleep?

Possibly, modestly. One placebo-controlled trial of the glycinate form found a small improvement in self-reported insomnia severity after four weeks. Reviews of other magnesium forms rate the evidence low to very low quality.

Is magnesium glycinate better absorbed than other forms?

It is often marketed that way, but we did not find a reliable independent study showing it, so we make no claim either way. The trials that exist for sleep and anxiety have not compared forms head to head.

How much magnesium glycinate is too much?

The EU upper limit for supplemental magnesium is 250 mg a day and the US figure is 350 mg, both based on loose stools rather than serious harm in people with healthy kidneys. Food magnesium does not count towards these limits.

Sources

Last reviewed 29 September 2026 · Next review March 2027 · How we rate evidence