Magnesium Benefits: What It Does, Who Needs More and How to Take It (UK)

What are the benefits of taking magnesium?

Taking magnesium helps your body do ten jobs that are officially recognised in Great Britain. Magnesium contributes to a reduction of tiredness and fatigue, to normal energy-yielding metabolism, to normal muscle function and to normal psychological function, among others. Most adults can get enough from food; a supplement tops up a diet that falls short.

These are the only magnesium health claims allowed on foods and supplements sold in Great Britain. Here they are word for word from the GB nutrition and health claims register, with what each means day to day.

The NHS describes magnesium in similar terms: it helps turn food into energy and helps the parathyroid glands, which make hormones important for bone health, work normally. If you feel low on energy, our guide to magnesium for energy goes further, and there are separate guides on magnesium for women and magnesium for men.

What the research shows beyond the authorised claims

Beyond the ten authorised claims, magnesium has been studied for blood pressure, sleep, cramps, migraines and anxiety. Results range from small but real effects to no clear benefit, and none of these is an authorised claim. Treat them as research findings, not reasons to replace advice from your GP.

iThe pattern is that people who are low in magnesium, or who already have a condition, tend to show the clearest changes. If you have high blood pressure, migraines or anxiety, keep to the treatment your GP has agreed and ask before adding anything.

Magnesium bisglycinate benefits

Magnesium bisglycinate gives the same authorised benefits as any other form, because the claims belong to the magnesium, not the compound. Its practical advantage is comfort: it is magnesium bound to two molecules of the amino acid glycine, and it tends to be gentler on the stomach than oxide or citrate at the same dose.

The catch is that bisglycinate is only about 14% magnesium by weight, so a “1,000mg magnesium bisglycinate” label gives roughly 141mg of magnesium. Always read the “Magnesium” line in the nutrition table rather than the compound weight.

On absorption, a small 1994 crossover trial in 12 people who had part of their bowel removed found glycinate and oxide were absorbed about equally overall, but glycinate was absorbed better by the four people who absorbed oxide worst, and it was better tolerated by everyone. That is a narrow group, so don’t read it as proof for healthy adults. Glycinate and bisglycinate are the same thing, as our glycinate vs bisglycinate guide explains, and the magnesium glycinate guide covers dosing and timing in detail.

How much magnesium do you need a day?

The NHS says adults aged 19 to 64 need 300mg of magnesium a day (men) or 270mg (women), and most people can get this from a varied diet. Taking 400mg or less a day from supplements is unlikely to cause harm. Taking more than 400mg in a short time can cause diarrhoea.

Food comes first: nuts, seeds, beans, wholegrains and leafy greens are the best sources, ranked in our list of foods high in magnesium. For amounts by age and goal, see how much magnesium per day.

Who may need more magnesium?

Most healthy adults eating a varied diet get enough. You are more likely to run low if you:

• are older, because you tend to eat less and absorb less (see magnesium for older adults)
• take a proton pump inhibitor such as omeprazole or lansoprazole long term: the MHRA has warned these can cause low magnesium
• take a loop or thiazide diuretic, which makes the kidneys pass more magnesium
• have type 2 diabetes, a gut condition such as Crohn’s or coeliac disease, or drink a lot of alcohol
• eat few nuts, seeds, wholegrains or greens

Low magnesium can cause tiredness, muscle cramps or twitches and loss of appetite, but these have many other causes too. Our page on the signs of magnesium deficiency explains the symptoms and why a blood test can miss it. If you are always tired, see a GP before reaching for a supplement: our guide to why you might always be tired lists the common causes.

Which form of magnesium is best?

The best form of magnesium is the one you tolerate and will take every day. Glycinate (bisglycinate) is usually gentlest on the stomach, citrate is well absorbed but can loosen stools, and oxide packs the most magnesium per tablet but is more likely to cause diarrhoea.

All 12 common forms are compared in our types of magnesium chart, and glycinate vs citrate vs threonate goes head to head on the three most asked about. If you want to compare brands, see the best magnesium glycinate supplements in the UK.

How to take magnesium

• Read the magnesium line. Add up the elemental magnesium from every product you take, including multivitamins and antacids.
• Take it with food if it upsets your stomach, or split it into two smaller doses.
• Pick a time you’ll stick to. Morning or evening both work; many people find an evening drink easiest to remember. See the best time to take magnesium.
• Give it time. Topping up magnesium is gradual, usually weeks rather than days, as our guide to how long magnesium takes to work explains.
• Stay at 400mg or less a day from supplements unless a doctor advises otherwise.

Is magnesium safe? Side effects and medicines

Magnesium is safe for most adults at 400mg a day or less from supplements. The commonest side effects are diarrhoea, stomach cramps and nausea, usually from high doses or from oxide and citrate. Healthy kidneys clear any extra, so dangerously high blood magnesium is rare.

• Kidney disease: don’t take a magnesium supplement unless your kidney team or GP has advised it, because magnesium can build up.
• Medicines: magnesium can stop some medicines being absorbed properly, including some antibiotics such as doxycycline and ciprofloxacin, levothyroxine and bisphosphonates such as alendronic acid. Ask a pharmacist how far apart to take them.
• Pregnancy and breastfeeding: talk to your midwife or GP before taking any supplement. We don’t recommend our products during pregnancy or breastfeeding.
• Get help: call 999 for weakness with drowsiness, a slow heartbeat or trouble breathing after taking magnesium.

The full list of side effects, symptoms of too much magnesium and medicine interactions is in our magnesium side effects guide.

Where Evopure fits

Evopure makes one magnesium product. The Magnesium Glycinate Sleep Complex is a berry-flavoured drink powder with 290mg of magnesium (77% NRV) per 4.75g serving, from 1,000mg magnesium bisglycinate and 900mg magnesium citrate. It also contains 500mg glycine, 100mg L-theanine, oat straw, hops, chamomile and passionflower, which are listed as ingredients only. It contains no melatonin, is vegan and is made in the UK.

Magnesium contributes to a reduction of tiredness and fatigue, to normal psychological function and to normal muscle function. At 290mg it sits inside the NHS 400mg guide for supplements, so check the labels of anything else you take that contains magnesium.

The Reishi Mushroom Adaptogenic Complex is a reishi hot chocolate with 0.5g reishi, 0.5g maca and 0.3g cinnamon per 8g, and contains a little natural caffeine from the cocoa. The Broad Spectrum CBD Capsules give one 10mg capsule of CBD, so there is nothing to measure. They are for adults only. If you take any regular medicines, check with a GP or pharmacist first.

The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.

Next step

Magnesium Glycinate Sleep Complex

If you want a magnesium top-up you’ll actually take, the Magnesium Glycinate Sleep Complex gives 290mg of magnesium per serving as a berry drink rather than another tablet.

Add Magnesium Glycinate Sleep Complex to bag See ingredients and reviews

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