Last updated: October 2026
Women need about 270mg of magnesium a day, and many get less than that from food. Magnesium contributes to the reduction of tiredness and fatigue, normal muscle function, normal psychological function and the maintenance of normal bones. It is especially useful around periods and PMS, in perimenopause and after 50. Glycinate is the gentlest form for daily use.
This guide explains what magnesium does for women, the benefits at each life stage, how much you need, the best type, signs you may be low, and who should check first.
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 the 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
Some 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
| Life stage | Why magnesium matters | Read more |
|---|---|---|
| 20s and 30s | PMS, period cramps, stress and sleep | Magnesium for PMS |
| Pregnancy | Leg cramps are common; always check with your midwife first | Magnesium in pregnancy |
| PCOS | Many women with PCOS ask about magnesium | Magnesium for PCOS |
| Over 40: perimenopause | Broken sleep, tiredness and low mood often start here | Magnesium for menopause |
| Over 50: menopause | Sleep, tiredness and bone health | Magnesium for menopause |
| Over 60 | Absorption can fall with age, and some medicines lower magnesium | See “Who should check first” below |
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 148mg 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.
See also PMS symptoms.
FAQs
Should women take magnesium daily?
Most women can get enough magnesium from a varied diet, but a daily supplement of up to 400mg is unlikely to cause harm and can help with tiredness, sleep and PMS. Taking it daily works better than taking it occasionally.
Is magnesium good for female hormones?
Magnesium does not change hormone levels, but it can help with symptoms linked to hormonal changes, such as premenstrual bloating, tiredness and broken sleep in perimenopause.
Which magnesium is best for women?
Magnesium glycinate is the best all-rounder for most women because it is gentle on the stomach and suits daily or evening use. Citrate is better if you also get constipation.
How much magnesium does a woman need a day?
The NHS says women aged 19 to 64 need 270mg a day, mostly from food. Supplements of 400mg or less a day are unlikely to cause harm.
What is the best magnesium for women over 50?
Glycinate is a good first choice for women over 50, especially for sleep and tiredness. Check with your GP first if you take long-term heartburn medicines, osteoporosis medicines or thyroid medicine.
Can I take magnesium alongside CBD?
Yes, many women take both in an evening routine. If you take prescription medicines, check with your pharmacist before using CBD.
Sources
- NHS. Vitamins and minerals: magnesium.
- MHRA. Proton pump inhibitors in long-term use: reports of hypomagnesaemia.
- Walker AF et al (1998). Magnesium supplementation alleviates premenstrual symptoms of fluid retention. Journal of Women’s Health.
- Schuster J et al (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep. Nature and Science of Sleep.
This guide is general information, not medical advice.
