Everyone’s taking this mineral for their sleep; a nutritionist explains how to make magnesium work for you

What do the Sleepy Girl Mocktail and Epsom bath salts have in common? They’re both supposed to help you peacefully drift off for the perfect night’s sleep, and they both contain the same ‘super mineral’: magnesium.

Sales of magnesium supplements have skyrocketed, as it’s promoted everywhere as the hot new wellness aid. As a nutritionist, I can tell you that magnesium is an essential mineral that we need daily, and it’s involved in over 300 processes in the body. These include bone health, muscle and nerve function, stress regulation and heart rhythm – as well as sleep and relaxation. It does this in a number of ways, such as helping calm the nervous system, relaxing muscles, potentially supporting melatonin regulation, and playing a role in stress management.

Next, read how to sleep better, find out the importance of a morning routine and why you're always tired.

There is evidence that magnesium really can improve sleep, including a trial of the type that we scientists love: a randomised, placebo-controlled study. UK adults, aged 18-65 and suffering poor sleep, measured their sleep quality, mood and related health outcomes. Results showed improvements in all three areas with magnesium compared to placebo. (Though we’d always like to see more longer-term clinical trials looking at different populations and settings to back this up.)

However, where it gets complicated is the fact that there are multiple different types of magnesium and ways of getting it into your body, and it can be a minefield out there. Different forms can target digestion, energy, muscle function or sleep, so it’s important to select the right type for your needs. What’s more, Epsom salts (magnesium sulfate) are often used in baths to help relax muscles. While they can feel soothing, evidence that magnesium is absorbed through the skin or corrects deficiency is limited.

Here are the different types of magnesium that can help different sleep problems.

Sleep issue: stress and a racing mind before bed

What to take? Magnesium glycinate

Nutritionist know-how: Stress is one of the most common causes of sleep problems, and we all know how frustrating it can be when your mind won’t switch off due to excessive thoughts. Magnesium glycinate contains the amino acid glycine, which has calming properties. The magnesium regulates GABA (a calming neurotransmitter) and can lower stress and anxiety levels. A dose of 150-300mg elemental magnesium taken 1-2 hours before bedtime is usually recommended, with some studies showing quicker sleep onset. (However there are mixed results overall and more research in to this area is needed.)

Sleep issue: trouble dropping off to sleep

What to take? Magnesium L-threonate

Nutritionist know-how: If you are frequently finding it difficult to fall asleep, this could be due to an imbalance in melatonin, GABA and nervous system activation. Magnesium L-threonate is a compound known to cross the blood-brain barrier, supporting the nervous system. In turn, higher magnesium levels in the brain may support deep sleep and mental calmness. You can take this supplement in powder or capsule form and the usual dose is ~1 g/day, taken in the evening. A recent study found Mg L-threonate improved sleep quality, including deeper sleep stages and good daytime functioning.

Sleep issue: restlessness

What to take? Magnesium glycinate

Nutritionist know-how: We’ve all experienced tossing and turning all night, where your legs are restless. This could be due to neuromuscular excitability or minor imbalances in magnesium and calcium. Magnesium glycinate may help due to its calming effects, allowing your body to enter the parasympathetic nervous system pathway (rest and digest) which can help reduce nighttime restlessness. Again, the dose would be between 150-300mg in the evening.

Sleep issue: waking up during the night

What to take? Either magnesium glycinate or L-threonate

Nutritionist know-how: Disrupted nights can lead to severe fatigue as you’re not getting enough good quality deep sleep. The effect that magnesium has on GABA, melatonin (the sleep hormone) and your nervous system may help reduce the number of nighttime wakings, especially in those who have low magnesium levels. Research suggests a 150-300mg dose 1 hour before bed may help you fall asleep more quickly, but there’s still inconsistent evidence on sleep duration.

Do you need to take a magnesium supplement?

Many of us are deficient in magnesium and this can be due to increased ultra-processed food consumption, food grown in soil that’s depleted in minerals, food processing, or high stress levels. National nutrition surveys suggest that we aren’t eating enough magnesium-containing foods and, as a nutritionist, I am all about a food-first approach. I’d recommend eating nuts and seeds (almonds and pumpkin seeds), green leafy vegetables (spinach and broccoli), wholegrains, legumes, cereals, bananas and dates – and even dark chocolate.

So, can magnesium improve your sleep?

There is no magic pill for sleep, not even a magnesium one. Better rest usually comes from a combination of good nutrition, consistent routines, stress management and healthy lifestyle habits.

Start by assessing your diet and whether you regularly eat magnesium-rich foods, such as those above. For some people, improving diet may be enough. If sleep problems persist, a magnesium supplement may be worth trying, but there is no guarantee it will help.

If your problem is severe insomnia, sleep apnoea or major hormone or thyroid disorders, then magnesium will not help, and you should get medical advice.

Despite social media claims, magnesium is not a guaranteed sleep cure. It may help those who are deficient, but evidence is mixed, and more UK-based research is needed before firm conclusions can be drawn. So, the jury is still out.

While generally safe for healthy adults, magnesium may be unsuitable for people with certain conditions, such as kidney disease, and should only be taken with professional guidance.

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