Magnesium for sleep: what does the research say?

Lots of people take magnesium to help them sleep, and scientists are taking a closer look at it too.¹ Some early studies have found positive results, mostly in older adults.^2,3 But the studies are small, so we can't say for sure yet that it helps.^2,3

In the UK, supplement brands aren't allowed to say magnesium helps you sleep. There's no approved health claim for it yet.⁴ If you've slept badly for months, or it's making daily life hard, see a GP.⁵

Why are scientists interested in magnesium and sleep?

Magnesium is one of the most common minerals in your body. It's needed for more than 300 reactions that keep your cells working.¹

Scientists think magnesium may affect brain chemicals linked to sleep, such as GABA and melatonin. They've also found that magnesium levels inside cells rise and fall over the day, in time with your body clock.¹ A lot of this research is in animals or cells in a lab. So we don't know yet if it works the same way in people.¹

Does magnesium help you sleep?

The early signs are interesting, but the research isn't strong enough yet to say for sure.

In 2022, a team of researchers looked at all the studies they could find on magnesium and sleep in adults. They found nine.² Some looked at what people already eat. Others gave people magnesium or a dummy pill (called a placebo) to compare.

Studies of what people eat

These studies can show a link between two things. They can't show that one thing causes the other.

• 2011, Japan: in 3,304 young women, those who ate more magnesium tended to sleep at earlier times.⁶

• 2015, China: in 98 people having kidney dialysis, those with more magnesium in their blood felt sleepier in the day.⁷

• 2018, China: in 1,487 adults, women who ate more magnesium were less likely to fall asleep in the day. There was no link in men.⁸

• 2020, Turkey: in 3,262 adults, people who slept better tended to eat more magnesium. There was no link with how long they slept.⁹

Studies that gave people magnesium

Five studies gave people magnesium or a placebo. They were all small, and most were in older adults.

• 1999: 45 people with leg cramps at night. There was no clear difference from the placebo.¹⁰

• 2002: 12 older adults. Those taking magnesium had more deep sleep, measured in a sleep lab.¹¹ 

• 2010: 100 adults over 51 who slept badly. Sleep got better in both groups, including the people taking the placebo. So it's hard to say magnesium made the difference.¹²

• 2012: 46 older adults with insomnia (trouble sleeping). People taking magnesium slept longer and fell asleep faster than people taking the placebo.¹³ 

• 2016: 44 adults aged 50 to 70. There was no clear difference in sleep.¹⁴

What the reviews say

A 2021 review combined three of these kinds of studies, with 151 older adults in total. People taking magnesium fell asleep a little faster than people taking a placebo. But the review rated the evidence as low quality, so it couldn't give firm advice.³ 

A 2025 review looked at this research and more. It found links between low magnesium and poor sleep. It said we now need better studies to find out if one causes the other.¹

So the early signs are worth watching. But they're not strong enough yet to say magnesium will change how you sleep.

What does magnesium do in the body?

Magnesium contributes to normal functioning of the nervous system. Magnesium contributes to normal psychological function. Magnesium contributes to normal muscle function.⁴

You get magnesium from food like spinach, nuts and wholemeal bread. Most adults need 270mg to 300mg a day.¹⁵ A varied, balanced diet is the best place to start.

Is one type of magnesium better for sleep?

No type of magnesium has been shown to work better than another for sleep.^2,3 These are the types you'll see most:

When should you take magnesium?

There's no best time backed by research. Try to take it at the same time each day. If it upsets your stomach, take it with food.

How much magnesium is safe?

The NHS says taking 400mg or less a day from supplements is unlikely to cause harm. Taking more than 400mg for a short time can give you diarrhoea. We don't know enough yet about high doses over a long time.¹⁵ 

Who should check before taking magnesium

Talk to a pharmacist or doctor first if any of these apply to you. 

• You have kidney disease: Your kidneys get rid of extra magnesium. If they don't work well, it can build up in your body.

• You take other medicines: Magnesium can stop your body taking in some medicines properly. These include some antibiotics (like ciprofloxacin), some bone medicines (like alendronic acid) and levothyroxine for your thyroid.¹⁶

• You're pregnant or breastfeeding: Ask your midwife, GP, or pharmacist.

• Buy from a seller you trust: In August 2025, the UK medicines regulator told parents to stop using a brand of children's magnesium gummies. The gummies had melatonin in them, but it wasn't on the label. In the UK, melatonin is a medicine you need a prescription for.¹⁷ Buy supplements from a registered UK pharmacy or a seller you trust.

The numan take

Good sleep matters for your health. Big studies have linked sleeping too little or too much with obesity, diabetes, high blood pressure and heart disease.¹⁸

The NHS suggests you:⁵

• Get up at the same time every day.

• Relax for at least an hour before bed.

• Keep your bedroom dark and quiet.

• Exercise in the day, but not in the 4 hours before bed.

• Don't have alcohol, tea or coffee in the 6 hours before bed.

• Put your phone away before bed.

See a GP if changing your habits hasn't helped, you've had trouble sleeping for months, or it's making daily life hard to cope with.⁵

Frequently asked questions

Does magnesium help you sleep? Some early studies have found positive results, mostly in older adults. But they're small, and there's no approved UK health claim that magnesium helps sleep.^2-4 

Which magnesium is best for sleep? No type has been shown to work better than another for sleep.^2,3 Glycinate and citrate tend to be gentler on the stomach than oxide. 

Does the NHS recommend magnesium for sleep? No. The NHS advice on insomnia doesn't mention magnesium. It says to check with your doctor before taking anything for sleep problems.⁵

Is it OK to take magnesium every night? For most adults, yes, if you keep to the NHS advice of 400mg or less a day from supplements.¹⁵ Ask a pharmacist first if you have kidney disease or take a medicine that can be affected by it.

Does magnesium make you sleepy? Magnesium isn't a sleeping pill. It isn't licensed as a sleep medicine in the UK. [Confirm with Clinical and Regulatory.]

How long does magnesium take to work for sleep? We can't say. The studies so far are too small to give a clear answer.^2,3

References

^{1 He C, Wang B, Chen X, Xu J, Yang Y, Yuan M. The mechanisms of magnesium in sleep disorders. Nat Sci Sleep. 2025;17:2639-56. doi:10.2147/NSS.S552646.}

^{2 Arab A, Rafie N, Amani R, Shirani F. The role of magnesium in sleep health: a systematic review of available literature. Biol Trace Elem Res. 2023;201(1):121-8. doi:10.1007/s12011-022-03162-1. PMID: 35184264.}

^{3 Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review & meta-analysis. BMC Complement Med Ther. 2021;21(1):125. doi:10.1186/s12906-021-03297-z. PMID: 33865376. Correction in: BMC Complement Med Ther. 2024;24:418. doi:10.1186/s12906-024-04721-w.}

^{4 Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register [Internet]. London: DHSC; [date if shown] [cited 2026 Oct 26]. Available from: https://www.gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register}

^{5 NHS. Insomnia [Internet]. London: NHS; [date if shown] [cited 2026 Oct 26]. Available from: https://www.nhs.uk/conditions/insomnia/}

^{6 Sato-Mito N, Sasaki S, Murakami K, Okubo H, Takahashi Y, Shibata S, et al. The midpoint of sleep is associated with dietary intake and dietary behavior among young Japanese women. Sleep Med. 2011;12(3):289-94.}

^{7 Lai X, Chen W, Bian X, Wang T, Li J, Wang H, et al. Predictors of poor sleep quality and excessive daytime sleepiness in peritoneal dialysis patients. Ren Fail. 2015;37(1):61-5.}

^{8 Cao Y, Zhen S, Taylor AW, Appleton S, Atlantis E, Shi Z. Magnesium intake and sleep disorder symptoms: findings from the Jiangsu Nutrition Study of Chinese adults at five-year follow-up. Nutrients. 2018;10(10):1354.}

^{9 Çakir B, Kılınç FN, Uyar GÖ, Özenir Ç, Ekici EM, Karaismailoğlu E. The relationship between sleep duration, sleep quality and dietary intake in adults. Sleep Biol Rhythms. 2020;18(1):49-57.}

^{10 Frusso R, Zárate M, Augustovski F, Rubinstein A. Magnesium for the treatment of nocturnal leg cramps: a crossover randomized trial. J Fam Pract. 1999;48(11):868-71.}

^{11 Held K, Antonijevic IA, Künzel H, Uhr M, Wetter TC, Golly IC, et al. Oral Mg(2+) supplementation reverses age-related neuroendocrine and sleep EEG changes in humans. Pharmacopsychiatry. 2002;35(4):135-43.}

^{12 Nielsen FH, Johnson LK, Zeng H. Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleep. Magnes Res. 2010;23(4):158-68.}

^{13 Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161-9.}

^{14 Liu G, Weinger JG, Lu ZL, Xue F, Sadeghpour S. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults: a randomized, double-blind, placebo-controlled trial. J Alzheimers Dis. 2016;49(4):971-90.}

^{15 NHS. Vitamins and minerals: others [Internet]. London: NHS; [cited 2026 Oct 26]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/others/}

^{16 Joint Formulary Committee. British National Formulary: magnesium interactions [Internet]. London: BMJ Group and Pharmaceutical Press; [cited 2026 Oct 26]. Available from: https://bnf.nice.org.uk/interactions/magnesium/} 

^{17 Medicines and Healthcare products Regulatory Agency. Parents and caregivers advised to stop all use of specific brand of kids' magnesium gummies due to the presence of an undeclared prescription-only medicine [Internet]. London: MHRA; 2025 Aug 18 [cited 2026 Oct 26]. Available from: https://www.gov.uk/government/news/parents-and-caregivers-advised-to-stop-all-use-of-specific-brand-of-kids-magnesium-gummies-due-to-the-presence-of-an-undeclared-prescription-only-med}

^{18 Buxton OM, Marcelli E. Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States. Soc Sci Med. 2010;71(5):1027-36.}