Magnesium for anxiety and stress: is there evidence?

What does the best review say about magnesium for anxiety?

In 2017, researchers at the University of Leeds reviewed 18 studies of magnesium, alone or with other ingredients, for anxiety and stress. Every study recruited people already prone to anxiety: mildly anxious adults, women with premenstrual syndrome, women after giving birth, and people with high blood pressure.

• In anxious people, four of eight studies found a benefit.
• In premenstrual syndrome, four of seven did.
• After giving birth, magnesium made no difference.

The reviewers concluded the evidence is “suggestive” but of poor quality, and that proper trials are needed. No study used a validated measure of stress as its main result.

Does magnesium help with stress?

A 2018 French trial gave 264 stressed adults with low-normal blood magnesium either magnesium with vitamin B6 or magnesium alone for eight weeks. Stress scores fell by more than 40% in both groups. Because there was no placebo group, we cannot tell how much of that was magnesium. The trial was funded by the company that makes both products.

Does magnesium help low mood or depression?

A 2017 trial in Vermont gave 126 adults with mild to moderate depression six weeks of magnesium chloride (248 mg of magnesium a day) and six weeks of no treatment, in random order. Depression scores improved by six points more on magnesium, and anxiety scores by four and a half, which is a large effect. But participants knew when they were taking magnesium, and there was no placebo, so expectation could explain much of the result. It needs repeating with a placebo.

Does magnesium help premenstrual mood?

A small 1991 Italian trial in 32 women found that magnesium taken in the second half of the cycle improved premenstrual mood scores compared with placebo. It is promising but small and old. A later Italian trial in women with menstrual migraine also found premenstrual complaints improved on magnesium: see migraine.

Why is magnesium linked to the nervous system at all?

Magnesium helps regulate nerve signalling, including the NMDA receptor and the body’s stress-hormone system. Animal studies of magnesium deficiency show anxious behaviour, and some studies find lower magnesium in people with depression. That makes it a reasonable thing to study. It does not show that supplements help people with normal levels. If you have risk factors for being short of magnesium, see signs of low magnesium.

Should you try it?

If you want to, it is low-risk at up to 400 mg a day for most adults, provided you don’t have kidney disease and have checked the medicines it affects. Just keep expectations modest. Glycinate is the gentlest form on the gut, and dosage and timing covers how much to take. Many people who try magnesium for anxiety are also hoping for better sleep, where the evidence is a little stronger. If anxiety or low mood is affecting your daily life, talk to your GP: talking therapies and, where needed, medication have far stronger evidence. You can also refer yourself to NHS Talking Therapies in England.

What doesn’t the evidence show?

That magnesium treats anxiety disorders, panic attacks or depression, or that any form is better than another for mood.