In a 24-hour society that prioritises connectivity and productivity, it’s no wonder so many people struggle to achieve regular restful sleep. It’s thought around two-thirds of adults in the western world fail to get the recommended eight hours a night – with women also rating their sleep quality as lower and reporting more fluctuations in sleep quality than men. Decades of research confirm the importance of sleep for every aspect of health. This doesn’t makesleeping any easier, though. Andwhere there is struggle, there are aggressively marketed ‘solutions’ – magnesium supps being the latest.
Meet the expert: Dr Sammie Gill is a registered dietitian specialising in nutritional immunology
Magnesium is an essential mineral involved in more than 300 bodily processes. Plant-based food sources include leafy green vegetables, nuts, seeds, legumes and whole grains. Animal products also contain magnesium, but in smaller amounts. In the UK, the daily magnesium target is 270mg for women, but the most recent National Diet and Nutrition Survey data found 17% of UK adults aged 19 to 64 have magnesium intakes well below the recommended level – and a review in the journal Nutrients found deficiency was more commonly noted in women than in men.
It’s thought that magnesium can support sleep by: influencing levels of neurotransmitters that switch the brain ‘off’, such as gamma-aminobutyric acid (GABA); supporting the production of hormones involved in the sleep-wake cycle, such as melatonin; dampening the stress response and lowering stress hormones, such as cortisol; and acting as a timekeeper by helping to regulate the internal ‘clocks’ of every cell in the body.
The combined effect of these mechanisms is believed to calm the central nervous system (brain and spinal cord) and decrease feelings of anxiety while promoting muscle relaxation and supporting maintenance of normal sleep-wake cycles. But while observational studies indicate sleep-promoting effects, limited gold-standard trials report mixed results.
Supplementation’s effectiveness can also depend on the type of magnesium used. It needs to be able to cross the blood-brain barrier in a form usable by brain cells and some kinds are more brain bioavailable than others. One promising type is magnesium threonate – a recent trial showed daily supplementation for three weeks improved sleep quality and daytime alertness in people with self-reported sleep problems.
So, should everyone turn to magnesium for sleep? No. If you eat a diverse, plant-first diet and consider yourself a healthy sleeper, magnesium supplementation is unnecessary. If you struggle to sleep despite eating well, try (free!) sleep strategies backed by more robust science first, focusing on regularity, timing, temperature and lighting.
That said, if you suspect you’re not getting enough magnesium from your diet – or tests of your nutrient levels reveal this to be the case – and you also have difficulty sleeping, it’s worth giving it a shot.
But remember, health is individual and multifactorial; just because it worked for your favourite wellness TikTok-er doesn’t mean the same is guaranteed for you – and there are risks involved with over-consuming magnesium, too. Consult your doctor if you’re taking other medications or have an existing health condition; shop smartly (see my picks below) and measure success to see if you get ROI. Record your baseline sleep, then try one month with magnesium followed by a month without.
2 snooze-worthy supplements you can trust
Uses a patented form of the mineral that is widely used in clinical studies.
This contains chelated magnesium, which is easier to absorb.
Third-party tested and has no artificial ingredients or preservatives.
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