Magnesium: the hype and the help

Magnesium has become the wellness world's favourite mineral, promised to fix everything from cramps to sleep. It genuinely matters: it helps turn food into energy. But the evidence that magnesium supplements fix PMS is weak and mixed.

What the evidence says

• The NHS says supplements such as magnesium may help PMS, but there is not much evidence that they work.
• ACOG, the US doctors' group, says magnesium may help with bloating, breast tenderness and mood symptoms.
• A 2025 review of 31 trials found too little evidence to say magnesium helps PMS mood symptoms. Calcium and vitamin B6 looked more promising, though the trials were small.

So the honest summary is: it might help a few people a little, and it is not proven. For period pain, the NHS advice is heat, gentle exercise, massage and painkillers. Magnesium is not on that list, and ACOG says there is not enough research to recommend magnesium or vitamin B1 for period pain.

Food first

The NHS says you should be able to get all the magnesium you need from a varied diet. Good sources include:

• Spinach and other leafy greens
• Nuts
• Wholemeal bread and other wholegrain foods

If you want to try a supplement

Talk to a pharmacist first. Keep a symptom diary for at least 2 cycles before and during, so you can tell whether anything changed. If nothing improves after a few cycles, it is fine to stop.