Magnesium for sleep: what the research shows
Does magnesium help you sleep? What the trials show, which form to choose, how much to take and when, with NHS guidance on safe amounts.
- Written by
- Amy D
- Reviewed by
- Nooroots team
- Last updated
- Reading time
- 9 min read
Overview
Magnesium may help you sleep a little, especially if your diet is low in it. In a 2025 trial of 155 adults who slept poorly, 250 mg a day for 4 weeks improved sleep scores slightly more than a placebo, but other trials disagree. The NHS says 400 mg or less a day from supplements is unlikely to cause harm.
Key points
- Evidence: a few small trials, a slight benefit at best and mixed results overall.
- Who gains most: people who get too little magnesium from food.
- Form: glycinate has the newest positive sleep trial; citrate and threonate results are mixed.
- Dose: trials used 250 to 500 mg; the NHS guide is 400 mg or less from supplements.
- Timing: take it in the evening and give it 4 to 8 weeks.
Does magnesium help you sleep?
It may help a little, especially if your diet is low in magnesium. Trials of magnesium for sleep are small and their results are mixed, so think of it as one part of a good evening routine, not a sleeping pill.
Magnesium is a mineral your body needs every day. Adults need 270 to 300 mg a day, and most can get it from food [1]. Magnesium contributes to the normal functioning of the nervous system and to normal psychological function. These are authorised health claims in the UK [2].
Weighing it up against melatonin? Our guide to melatonin in the UK explains the rules and the options.
What do the sleep trials show?
A small effect at best. Some trials found a modest benefit and others found none. A 2026 review of 12 trials called the results inconsistent and rated the evidence low to very low [4].
Each finding has a label: Strong (several good trials agree), Moderate, Early (one or two small trials) or Mixed.
| Study | People | Dose a day | Length | Result | Evidence |
|---|---|---|---|---|---|
| Schuster 2025 [3] | 155 adults aged 18 to 65 who slept poorly | 250 mg magnesium (bisglycinate) | 4 weeks | Sleep scores improved by 3.9 points, vs 2.3 on placebo; a small effect | Early |
| Abbasi 2012 [5] | 46 older adults with insomnia | 500 mg magnesium | 8 weeks | Fell asleep sooner and slept more efficiently than on placebo | Early |
| Nielsen 2010 [6] | 100 adults aged 51 to 85 who slept poorly | 320 mg magnesium (citrate) | 7 weeks | Sleep improved, but just as much on placebo | Early |
| Mah 2021, review [7] | 3 trials, 151 older adults with insomnia | Various | Various | Fell asleep about 17 minutes sooner; low-quality trials | Early |
| Arab 2022, review [8] | 9 studies, 7,582 adults | Diet and supplements | Various | More magnesium linked with better sleep; trials disagree | Mixed |
| Lopresti 2026, review [4] | 12 trials in adults | Various | Various | Inconsistent results | Mixed |
Population studies link a higher magnesium intake with better sleep, but they can't show that magnesium is the cause [8]. In the 2025 trial, people who ate the least magnesium seemed to gain the most [3]. That fits the idea that magnesium helps most when you're not getting enough.
How does magnesium help you sleep?
No one knows for sure. Magnesium helps nerves send signals, and researchers think it may calm the nervous system by acting on GABA, a brain messenger that slows activity down [5]. This hasn't been proven in people.
Which magnesium is best for sleep?
Glycinate has the most recent positive sleep trial, but no study has compared forms head to head for sleep. Choose a well-absorbed form at a dose you can take every day.
| Form | Sleep research | Worth knowing |
|---|---|---|
| Glycinate (bisglycinate) | One 2025 trial: a small benefit [3] | Magnesium joined to the amino acid glycine |
| Citrate | One 2010 trial: no better than placebo [6] | Absorbed better than oxide in a 60-day trial [9] |
| L-threonate | Two trials: better on some measures, not others [10, 11] | Trials used 1 to 2 g of the compound a day |
| Malate | Little sleep research | Often combined with other forms |
| Oxide | Little sleep research | Absorbed no better than placebo in that 60-day trial [9] |
Magnesium L-threonate is often sold for sleep. In a 2024 trial of 80 adults aged 35 to 55 with sleep problems, 1 g a day for 21 days improved deep and REM sleep scores on a sleep-tracking ring compared with a placebo [10]. A 2026 trial of 100 adults aged 18 to 45 used 2 g a day for 6 weeks. Self-rated sleep-related impairment improved, but the ring showed no difference in sleep [11].
Read more in our magnesium glycinate guide and our guide to magnesium citrate.
How much magnesium for sleep?
Sleep trials used 250 to 500 mg of magnesium a day [3, 5, 6]. The NHS says adults need 270 to 300 mg a day in total, and that taking 400 mg or less a day from supplements is unlikely to cause harm [1].
- Read the magnesium figure. Labels often show the compound weight first. 1,000 mg of magnesium bisglycinate gives only about 140 mg of magnesium.
- Count every supplement. Add up magnesium from multivitamins and other products too.
- Look at your plate. Spinach, nuts and wholemeal bread are good sources [1].
- Ask before going higher. The 500 mg used in one trial is above the NHS guide, so ask your GP before taking that much.
When should you take magnesium?
For sleep, take it in the evening. No trial has compared timings, so the best time is one you'll stick to every day.
Pair it with good sleep habits. The NHS suggests getting up at the same time every day, relaxing for at least an hour before bed, and having no alcohol, tea or coffee for at least 6 hours before bed [12].
How long does magnesium take to work?
Give it 4 to 8 weeks of daily use. Trials measured their results after 3 to 8 weeks of taking it, not after a single dose [3, 5, 10].
Does magnesium make you sleepy?
Not in the way a sleeping pill does. Magnesium isn't a sedative, and the trials measured sleep quality over weeks, not drowsiness after a dose.
If anything, magnesium contributes to the reduction of tiredness and fatigue, another authorised claim [2]. In one trial, people taking magnesium L-threonate reported more daytime energy and alertness than those on a placebo [10].
Can you take magnesium every night?
Yes, for most adults, as long as magnesium from all your supplements stays at 400 mg a day or less [1].
- Kidney problems. Ask your GP first, because your kidneys clear the extra magnesium.
- Medicines or pregnancy. Some antibiotics and bone medicines need to be taken a few hours apart from magnesium. If you take regular medicines, or you're pregnant or breastfeeding, ask your GP or pharmacist first.
- Long-term poor sleep. See your GP if you've had trouble sleeping for months, or it's making daily life hard to cope with [12].
Where Nooroots fits
Nooroots Triple Magnesium combines glycinate, citrate and malate to give 301 mg of magnesium in three capsules a day. It's made for the evening, as part of your wind-down.
Magnesium helps reduce tiredness and fatigue, and contributes to the normal functioning of the nervous system and to normal psychological function.
Coming soon. Triple Magnesium isn't on sale yet.
Many people pair magnesium with ashwagandha. Read ashwagandha and magnesium: can you take them together?
Frequently asked questions
Does magnesium glycinate help you sleep?
It may help a little. In a 2025 trial of 155 adults who slept poorly, magnesium bisglycinate giving 250 mg of magnesium a day improved sleep scores slightly more than a placebo after 4 weeks [3].
Should I take magnesium right before bed?
It doesn't need to be right before bed. Many people take it an hour or two before, but no study has tested the best gap, and taking it every day for several weeks matters more than the exact time.
Can I take glycinate in the morning?
Yes. No trial has compared morning and evening doses, so take it when you'll remember. For sleep, most people choose the evening.
Does magnesium citrate help you sleep?
There's little evidence that it does. In a 2010 trial of 100 adults aged 51 to 85 who slept poorly, 320 mg of magnesium as citrate for 7 weeks improved sleep no more than a placebo [6].
Does magnesium cause next-day tiredness?
It isn't known to. In a 2024 trial, adults taking magnesium L-threonate reported more daytime energy and alertness than those on a placebo [10].
Is magnesium glycinate the same as bisglycinate?
Usually, yes. "Bisglycinate" spells out that each magnesium is paired with two glycines. Check the ingredients for magnesium oxide, which some "buffered" products add.
References
Every study here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We review it when new research is published.
- NHS. Vitamins and minerals: others (magnesium section). Page last reviewed 3 August 2020. Accessed 17 October 2026. nhs.uk/conditions/vitamins-and-minerals/others
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register
- Schuster J et al. (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and Science of Sleep 17: 2027–2040. doi:10.2147/NSS.S524348
- Lopresti AL et al. (2026). Magnesium supplementation for sleep in adults: a systematic review of randomized controlled trials. Journal of Dietary Supplements 23(5): 553–581. doi:10.1080/19390211.2026.2719670
- Abbasi B et al. (2012). The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences 17(12): 1161–1169. PMID 23853635
- Nielsen FH et al. (2010). Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleep. Magnesium Research 23(4): 158–168. PMID 21199787
- Mah J, Pitre T (2021). Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis. BMC Complementary Medicine and Therapies 21: 125. doi:10.1186/s12906-021-03297-z
- Arab A et al. (2022; in print 2023). The role of magnesium in sleep health: a systematic review of available literature. Biological Trace Element Research 201(1): 121–128. doi:10.1007/s12011-022-03162-1
- Walker AF et al. (2003). Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnesium Research 16(3): 183–191. PMID 14596323
- Hausenblas HA et al. (2024). Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: a randomized controlled trial. Sleep Medicine: X 8: 100121. doi:10.1016/j.sleepx.2024.100121
- Lopresti AL, Smith SJ (2026). The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Frontiers in Nutrition 12: 1729164. doi:10.3389/fnut.2025.1729164
- NHS. Insomnia. Page last reviewed 19 March 2024. nhs.uk/conditions/insomnia
