Best Magnesium for Sleep UK (2026): Glycinate vs Citrate, Dose and Research

Picks at a glance

Prices are one-off prices on brand and UK retailer pages in October 2026; Heights is priced as a monthly subscription. "Promising" here means a glycinate or well-absorbed form at a sensible dose with a clean label; "Early" means a low dose, added oxide, a lower-evidence form, or unclear labelling.

Does magnesium help you sleep?

Grade: Early. Magnesium may help a little, especially in older adults or people whose diet is low in magnesium, but the trials are small and the effects modest.

• A 2021 meta-analysis of three randomised trials in 151 older adults found people fell asleep about 17 minutes faster on magnesium than placebo, but total sleep time did not improve significantly. The authors rated the evidence low to very low quality.
• An 8-week trial in 46 older adults found 500mg of magnesium a day improved several sleep measures. That dose is above the level the NHS suggests for supplements.
• The best recent trial (Schuster et al., 2025) gave 155 adults with poor sleep 250mg of magnesium as bisglycinate or placebo for four weeks. Insomnia scores improved by 3.9 points with magnesium and 2.3 with placebo: a real but small difference. It was independently funded, but the capsules also delivered about 1.5g of glycine, which may itself aid sleep.

In plain terms: magnesium is not a sleeping pill. It may take the edge off for some people, and it is unlikely to help if your sleep problems come from stress, shift work, caffeine, alcohol, pain or a sleep disorder.

Which form is best for sleep?

No head-to-head trial shows one form is best for sleep. Glycinate is the sensible default because it is well absorbed, gentle on the gut and is the form used in the most recent positive trial.

Glycinate vs citrate for sleep

Both are well absorbed. Glycinate is gentler on the stomach and adds glycine, an amino acid that has been studied for sleep on its own at around 3g a night; most glycinate supplements give much less than that. Citrate is cheaper and well absorbed, but is more likely to loosen stools, which is why it is also used for constipation.

Our view: for sleep, choose glycinate. If you also want help with constipation, citrate may suit you better.

Buffered vs non-buffered glycinate

A "buffered" glycinate mixes magnesium glycinate with cheaper magnesium oxide. Oxide is more concentrated, so buffering raises the milligrams on the label and lowers the cost, but oxide is less well absorbed and more likely to upset the gut.

• Non-buffered (fully reacted): Viridian says its bisglycinate is fully reacted with no other forms.
• Buffered: Bare Biology states 85% bisglycinate and 15% oxide; VitaBright and Holland & Barrett also list oxide.
• Not stated: many brands do not say. "No oxide listed" is a good sign but not proof.

Buffered products are not useless, but if you are paying glycinate prices for gentleness and absorption, choose one that does not add oxide.

How much to take and when

The NHS says adults aged 19 to 64 need about 300mg a day (men) and 270mg a day (women), and that most people can get this from food. It advises that taking 400mg or less a day from supplements is unlikely to cause harm; more can cause diarrhoea.

• Check the elemental dose. "Magnesium glycinate 1,500mg" may contain only about 200 to 300mg of actual magnesium. Our table shows elemental magnesium.
• Start low. 100 to 200mg in the evening is a reasonable start; the 2025 trial used 250mg.
• Take it 30 to 60 minutes before bed, with or without food. Some people prefer to split the dose.
• Count all sources. Add magnesium from multivitamins, electrolyte drinks and sleep blends.
• Give it four weeks, then judge whether it helps.

Magnesium for sleep and anxiety

A 2017 systematic review found suggestive benefits of magnesium for mild anxiety in some vulnerable groups, but the studies were poor quality. Grade: Early. Magnesium is not a treatment for anxiety disorders. If anxiety is keeping you awake, NHS talking therapies and cognitive behavioural therapy for insomnia (CBT-I) have far stronger evidence.

Magnesium and sleep apnoea

People with obstructive sleep apnoea may have lower blood magnesium on average (Al Wadee et al., 2022), but that is an association, and no good trial shows magnesium treats apnoea. Grade: No direct evidence. If you snore loudly, someone has seen you stop breathing in your sleep, or you are very sleepy in the day, see your GP. Apnoea needs proper assessment and treatment, often with a CPAP machine.

How we chose

We checked each product on a live UK brand or major retailer page in October 2026 and compared:

• Elemental magnesium per daily dose, not the compound weight.
• Form, favouring glycinate for sleep.
• Buffering, noting any added oxide.
• Additives, such as magnesium stearate, colourings and gelatine capsules.
• Third-party testing, such as Informed Sport.
• Price per day at the full adult dose.

The picks

Viridian High Potency Magnesium Bisglycinate: best overall

Fully reacted bisglycinate with no other magnesium forms, 200mg of elemental magnesium in two plant capsules, from an ethical UK brand. A sensible dose within NHS guidance. Caveat: no third-party testing is published, and at about 53p a day it is not the cheapest.

DR.VEGAN Magnesium Glycinate: best value glycinate

300mg of elemental magnesium as glycinate in two capsules, about 43p a day, with a plain label. Caveat: no testing is published, and the brand does not say whether it is buffered, though no oxide is listed.

Heights Magnesium+: best for a clean label

300mg of elemental magnesium as glycinate in two capsules with no other additives listed, and the brand says every batch is third-party tested. Caveat: the lab is not named, and the £20 price is for a monthly subscription.

Nutrition Geeks Magnesium Glycinate 3-in-1: cheapest per day

Glycinate, citrate and malate giving 384mg in two capsules, about 22p a day. Caveat: 384mg is close to the 400mg NHS level, so do not stack it with other magnesium, and it contains magnesium stearate. Not a pure glycinate.

VitaBright Magnesium Glycinate: budget glycinate

300mg in two capsules for about 22p a day, with 180 capsules per pot. Caveat: it contains magnesium oxide, so it is a buffered product.

Holland & Barrett Magnesium Bisglycinate 375mg: high-street option

Easy to buy in store. Caveat: "375mg" is the compound weight; it gives only 85mg of elemental magnesium per capsule and contains oxide.

Bare Biology Ready & Rested: premium buffered glycinate

375mg in three capsules, clearly labelled as 85% bisglycinate and 15% oxide, from a brand that tests its products. Caveat: 375mg is near the top of the NHS supplement range, and it is buffered.

Puresport Ultra Magnesium: best tested option

Citrate, bisglycinate and taurate, 225mg in three capsules, with Informed Sport certification for athletes. Caveat: at about 83p a day it is expensive, and the full excipient list was not published on the page we checked.

BetterYou Magnesium Max 3-in-1 Powder: best powder

Citrate, glycinate and malate in a lemon and lime powder giving 375mg per teaspoon, about 33p a day. A good choice if you dislike capsules. Caveat: contains citrate, which can loosen stools, and stevia.

Cytoplan Magtein Magnesium L-Threonate: threonate option

144mg of elemental magnesium as Magtein L-threonate in three capsules. A 2024 trial of 80 adults found small improvements in wearable-tracked sleep scores and daytime functioning over three weeks. Caveat: the trial was short, small and industry-linked, and at about £1.67 a day this is by far the most expensive per milligram.

Who should be careful

• Kidney disease: your kidneys clear excess magnesium. Do not take supplements unless your kidney team agrees, as levels can build up (NHS SPS).
• Bisphosphonates for osteoporosis: take them at least two hours apart from magnesium (NIH).
• Tetracycline or quinolone antibiotics: take the antibiotic at least two hours before or four to six hours after magnesium.
• Long-term proton pump inhibitors (such as omeprazole): these can lower magnesium; ask your GP rather than self-treating.
• Heart or blood pressure medicines: check with a pharmacist.
• Pregnancy: stick to food sources unless your midwife or GP advises otherwise.

If in doubt, ask your pharmacist. Persistent insomnia is worth discussing with your GP, who can refer you for CBT-I.

Food first

You can usually meet your magnesium needs from food. Good sources, according to the NHS, include green leafy vegetables such as spinach, nuts, brown rice, wholemeal bread, fish, meat and dairy. A handful of almonds, a portion of spinach and a slice of wholemeal toast go a long way. Good sleep habits matter more: a regular wake-up time, daylight in the morning, less caffeine after midday, and less alcohol in the evening.

What to avoid

• Doses above 400mg a day from supplements, unless a doctor advises it.
• Labels showing only the compound weight. Look for "elemental magnesium" or "providing X mg magnesium".
• "Sleep blends" that hide doses inside proprietary mixes, especially with melatonin, which is prescription-only in the UK.
• Magnesium sprays and bath flakes sold for sleep: there is little evidence that much magnesium is absorbed through the skin.
• Relying on magnesium for apnoea or severe insomnia. See your GP.

Bottom line

Magnesium may help you fall asleep a little faster, but the evidence is small and the effect modest. If you want to try it, choose a glycinate giving 100 to 300mg of elemental magnesium in the evening, keep total supplements under 400mg a day, and judge it after four weeks. Viridian is our top pick for a fully reacted glycinate; DR.VEGAN and Heights are strong alternatives. For more on choosing a magnesium supplement for other reasons, see our best magnesium supplement guide.