Does magnesium help you sleep?

Magnesium is one of the most popular sleep supplements. It plays a role in hundreds of enzyme reactions, including those involved in nerve and muscle function. But does taking it improve sleep?

What the research shows

A 2021 systematic review and meta-analysis looked for randomized trials of oral magnesium for insomnia in older adults. It found only three small trials with 151 participants. Magnesium was associated with falling asleep about 17 minutes faster compared with placebo, but the reviewers rated the overall evidence as low quality, and total sleep time didn't clearly improve.

In short: a modest benefit is possible, particularly in older adults, but it isn't well proven.

Who may benefit most

The NIH Office of Dietary Supplements notes that many Americans get less magnesium from food than recommended. People most likely to have low intake include older adults, people with type 2 diabetes or gastrointestinal conditions, and people with alcohol use disorder. If your intake is low, correcting it may help sleep more than it would for someone who already gets enough.

Food first

Good sources include:

• Pumpkin seeds, almonds and cashews
• Spinach and other leafy greens
• Black beans, edamame and other legumes
• Whole grains and dark chocolate

Adult RDAs are about 310–420 mg a day depending on age and sex. Not sure you are sleeping enough? Start with how much sleep adults need.

If you supplement

The upper limit for supplemental magnesium is 350 mg per day for adults. Higher doses can cause digestive upset. People with kidney disease should avoid supplements unless a clinician recommends them.

Bigger levers

Consistent sleep timing, a cool dark room, less late caffeine and alcohol, and daytime activity have stronger evidence. See the best room temperature for sleep and our sleep optimization hub.