Magnesium for Sleep: What the Research Says

November 2, 2026

Magnesium is one of the most popular supplements for sleep, and many people take it as part of their evening routine. The research is promising but small: a 2021 review of three trials in older adults found people taking magnesium fell asleep about 17 minutes faster than those on a placebo, though the evidence was rated low quality. Good sleep habits matter more than any supplement.

Why people take magnesium in the evening

Magnesium contributes to the normal functioning of the nervous system and to normal psychological function. Many people find a magnesium drink or supplement a useful signal to start winding down, alongside switching off screens and keeping a regular bedtime.

What the research shows

2021 systematic review (Mah and Pitre): three randomised trials, 151 older adults with sleep problems. Those taking magnesium fell asleep 17 minutes faster on average than those taking a placebo. Total sleep time rose by about 16 minutes, but that was not statistically significant. The authors rated the evidence low to very low quality and called for better trials.
What we do not know yet: most studies are small, in older adults, and use different forms and doses. There is little research in younger, healthy adults.

Which form of magnesium?

Magnesium bisglycinate (also called glycinate) is a popular evening choice because it is gentle on the stomach. Citrate and oxide are more likely to have a laxative effect. Compare them in magnesium bisglycinate, explained.

How much and when?

Studies have used a range of doses. The NHS advises that 400mg or less a day from supplements is unlikely to cause harm. Many people take magnesium 30 to 60 minutes before bed. See the best time to take magnesium.

Habits that matter more than any supplement

Go to bed and get up at the same time every day, including weekends.
Keep your bedroom dark, quiet and cool.
Stop caffeine by early afternoon and go easy on alcohol in the evening.
Put screens away for the last half hour before bed.
Get daylight in the morning to set your body clock.

If poor sleep is affecting your daily life, or lasts more than a few weeks, talk to your GP.

Where Absorble fits

The Absorble Evening Shot is made for your wind-down: one 7.5ml spoonful of pineapple-flavoured liposomal magnesium bisglycinate, 30 to 60 minutes before bed. Each serving contains 75mg of magnesium (20% NRV).

Keep reading

Sources

This guide is for general information and is not medical advice. Food supplements should not replace a varied, balanced diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak to your GP or pharmacist before taking a new supplement.

Back to blog