Magnesium for Women: Benefits at Every Age, How Much and Best Type (UK)

What does magnesium do for women?

Magnesium is involved in more than 300 processes in the body, from muscle and nerve function to energy production and bone health. Women’s needs are slightly lower than men’s (270mg vs 300mg a day), but periods, pregnancy, menopause and some medicines can all affect how much you get and use. The officially approved UK benefits of magnesium apply to everyone, and several matter particularly to women.

Magnesium benefits for women

1. Less tiredness and fatigue

Magnesium contributes to a reduction of tiredness and fatigue and to normal energy-yielding metabolism, useful at any stage of life, and especially when sleep is broken.

2. PMS, bloating and water retention

In a University of Reading trial, women who took 200mg of magnesium a day had fewer premenstrual fluid retention symptoms by the second month, including bloating, swollen hands and feet and breast tenderness. See magnesium for PMS and magnesium for water retention.

3. Period cramps and muscle function

Magnesium contributes to normal muscle function, which is why many women take it for period cramps. The research on period pain specifically is limited, so treat it as a gentle extra. See magnesium for cramps.

4. Mood and stress

Magnesium contributes to normal psychological function and the normal functioning of the nervous system. Many women take it in the evening as part of a calming routine. See magnesium for anxiety.

5. Sleep

Glycinate is the most popular form for sleep, and a 2025 trial found a small improvement in insomnia scores in adults who slept poorly. See magnesium for sleep.

6. Bones

Magnesium contributes to the maintenance of normal bones. Bone density falls faster after menopause, so magnesium matters alongside calcium, vitamin D and strength exercise.

7. Migraines

iSome research suggests magnesium may help reduce how often migraines happen, including migraines linked to periods, but the evidence is mixed. If you get frequent migraines, talk to your GP. See magnesium for migraines.

Magnesium by age and life stage

How much magnesium do women need?

The NHS says women aged 19 to 64 need 270mg of magnesium a day, and that most people can get this from a varied diet. If you take a supplement, 400mg or less a day from supplements is unlikely to cause harm.

• Typical supplement: 100 to 300mg of elemental magnesium a day.
• Food sources: pumpkin seeds, almonds, spinach, beans, wholegrains and dark chocolate.
• Check the label for elemental magnesium, not the compound weight.

See the best time to take magnesium for timing.

Best magnesium for women

• Glycinate: the best all-rounder for daily use, sleep and PMS. Gentle on the stomach. See our magnesium glycinate guide.
• Citrate: good if you also get constipation or bloating. See magnesium for bloating.
• L-threonate: sometimes chosen for brain fog, though research is early.

Our Magnesium Glycinate Sleep Complex combines bisglycinate and citrate with calming botanicals, giving 290mg of magnesium per serving as an evening drink. For every form side by side, see magnesium glycinate vs other forms.

Signs you may be low in magnesium

Mildly low magnesium often has no clear symptoms. Muscle cramps or twitches, tiredness and weakness are sometimes linked to low magnesium, but they have many other causes too. A blood test is the only reliable check, so speak to your GP if you are worried rather than guessing from symptoms.

Who should check first?

• Pregnant or breastfeeding women: check with your midwife or GP before taking any supplement.
• Women with kidney disease: your kidneys clear excess magnesium.
• Women on long-term heartburn medicines (PPIs, such as omeprazole): the MHRA has warned that long-term use can lower magnesium levels, so ask your GP whether your levels should be checked.
• Women taking antibiotics, osteoporosis medicines or thyroid medicine: magnesium can reduce how well these are absorbed, so they may need to be taken a few hours apart. Ask your pharmacist.

Related guides

• PMS symptoms.
• PCOS has a new name: PMOS explained.
• A guide to PMDD.
• Inositol for women: the evidence for PCOS, fertility and side effects.
• If you can’t sleep in the week before your period, see insomnia before a period.
• Choosing a product? Our best magnesium supplement guide has an 8-point checklist.
• Period pain relief: what the evidence says.
• Pumpkin seeds for women.
• Perimenopause symptoms and the vitamins worth taking.
• Men need a little more, 300mg a day; see magnesium for men for their guide.
• For where magnesium sits alongside vitamin D, calcium and herbal remedies in midlife, see best supplements for menopause.
• See magnesium L-threonate (Magtein): evidence, dose and cost per mg.
• How much magnesium per day for a woman, at every age.
• Women need 270mg a day, and a handful of seeds goes a long way: see magnesium-rich foods for the best sources.
• Wondering about less common forms? Read magnesium taurate: benefits, dose and taurate vs glycinate.
• Shopping for her this Christmas? Our guide to wellness gifts for her mixes simple non-supplement ideas with a few warm evening drinks.
• For blends sold for women, our guide to what a magnesium complex is and whether it beats a single form shows what to look for on the label.
• Many women also need to think about iron; see iron supplements for women and how to take them.
• The types of magnesium and their benefits, form by form.
• Thinking of adding a herb? See whether you can take ashwagandha and magnesium together, and what women should check first.
• For tiredness that follows your cycle, read why you feel so tired on your period, including when low iron is the cause.
• For the NHS 400mg supplement guide and the first signs of taking too much, see magnesium side effects.
• Comparing options for midlife? Our CBD oil for menopause guide explains what CBD research does and doesn’t show.
• Over 60? See magnesium for older adults for how much you need in your 60s and 70s and which type suits you.
• For magnesium alongside vitamin D, iron, B12 and calcium, see supplements for women over 50 and 60.