Magnesium for women, daily amounts, PMS and period pain
How much magnesium women need, what it does, and what the trials found for PMS and period pain, with NHS amounts and safe limits.
- Written by
- Ben L.
- Last updated
- Reading time
- 8 min read
Overview
The NHS says women aged 19 to 64 need 270 mg of magnesium a day, and a varied diet should cover it. UK women average 224 mg from food. Small trials of magnesium for PMS and period pain had mixed results. Taking 400 mg or less a day from supplements is unlikely to cause harm.
Key points
- The NHS says women aged 19 to 64 need 270 mg of magnesium a day.
- UK women get 224 mg a day from food on average, and about 15% are below the lowest intake level.
- Small trials of magnesium for PMS had mixed results, and a 2025 review found too little evidence for mood symptoms.
- A Cochrane review called magnesium promising for period pain, with the best dose unclear.
- Taking 400 mg or less a day of magnesium from supplements is unlikely to cause harm.
A simple rule of thumb for magnesium is 270 mg a day for women aged 19 to 64, and a varied, balanced diet should cover it [1]. Many women in the UK eat a little less than that [2].
Magnesium does the same jobs in women's bodies as in men's. What's different is the research on periods. Small trials have tested magnesium for premenstrual symptoms and period pain, with mixed results.
What does magnesium do for women?
Magnesium helps turn the food you eat into energy, and helps the parathyroid glands work normally. These glands make hormones that matter for bone health [1].
In the UK, magnesium has authorised health claims. It contributes to a reduction of tiredness and fatigue, normal muscle function, normal psychological function and the maintenance of normal bones [3].
How much magnesium does a woman need?
The NHS says women aged 19 to 64 need 270 mg of magnesium a day, and men 300 mg [1].
The latest UK diet survey found women get 224 mg a day from food on average. About 15% of women were below the lowest intake level, the amount that's likely too little for most people [2].
In practice, the average woman is about 46 mg short of 270 mg. Our guides to how much magnesium per day and magnesium deficiency symptoms go into more detail.
Magnesium for PMS
The NHS lists magnesium among the supplements that may help with PMS, but says there's not much evidence that they work [4]. The trials are small, and they point in different directions.
| Study | What it found | Evidence |
|---|---|---|
| 38 women, 200 mg a day | Less bloating, swelling and breast tenderness in the second cycle, not the first [5] | Early |
| 32 women, from mid-cycle | Lower mood-related symptom scores [6] | Early |
| 85 women, 200 to 500 mg | The placebo group improved more than the magnesium groups [7] | Early |
| Review of 31 trials | Not enough evidence for magnesium on mood symptoms [8] | Early |
In a UK trial, 38 women took 200 mg of magnesium a day for two cycles. Fluid-retention symptoms such as bloating and breast tenderness eased more than with placebo, but only in the second month [5]. In an Italian trial of 32 women with PMS, magnesium taken three times a day from mid-cycle lowered overall and mood-related symptom scores [6].
A larger UK trial of 85 women compared 200, 350 and 500 mg with a placebo. The placebo, which contained sorbitol, reduced symptoms more than any magnesium dose [7]. A 2025 review of 31 trials found consistent effects on mood symptoms for vitamin B6, calcium and zinc, but not enough evidence for magnesium [8]. Our page of magnesium studies lists every trial in people on mood, sleep and energy.
The NHS also suggests regular exercise, a healthy diet, plenty of sleep, and a symptom diary for at least two cycles to take to a GP appointment [4].
Magnesium for period pain
A Cochrane review found three small trials where magnesium relieved period pain better than placebo, and women needed fewer extra painkillers. The authors called magnesium promising, but said the best dose was unclear, so they couldn't make a strong recommendation [9].
For period pain, the NHS suggests heat on your tummy, a warm bath, gentle exercise, massage, and painkillers like paracetamol or ibuprofen [10].
Magnesium in perimenopause and menopause
There's no separate magnesium figure for menopause. The NHS says women aged 19 to 64 need 270 mg a day, and that a varied, balanced diet should provide it [1].
Magnesium hasn't done well as a remedy for hot flushes. In a US trial, 289 women who'd had breast cancer and had bothersome hot flushes took 800 or 1,200 mg of magnesium oxide a day, or a placebo, for 8 weeks. Hot flush scores changed by a similar amount in every group, and the magnesium groups had more diarrhoea [11].
Bone health is the other reason magnesium comes up. Magnesium contributes to the maintenance of normal bones [3], and the NHS says women lose bone rapidly in the first few years after the menopause [12]. A review of 11 studies with 2,776 women after menopause found that those with osteoporosis had lower blood magnesium than women without it [13]. Studies like these show a link, not that magnesium prevents bone loss.
For sleep, our guide to magnesium for sleep covers the trials, and our guide to perimenopause symptoms covers why perimenopause can leave you tired.
Which magnesium is best for women?
We found no research showing women need a different form of magnesium from men. The amount differs, not the form. Our guide to magnesium glycinate vs citrate compares two common forms, and the PMS trials above used different forms.
Side effects and how much is too much
The NHS says taking 400 mg or less a day of magnesium from supplements is unlikely to cause any harm. Taking more than 400 mg for a short time can cause diarrhoea [1].
Here's a worked example. If you get 224 mg from food and take a 200 mg supplement, you have 424 mg in total. That still fits the NHS guidance, because its 400 mg line counts magnesium from supplements, not food [1][2].
Check with a GP or pharmacist before starting regular supplements if you take any medicines [4].
Where Nooroots fits
Nooroots Triple Magnesium is a food supplement with magnesium glycinate, citrate and malate, in three capsules a day. It's for topping up your daily intake alongside a varied diet.
Magnesium contributes to a reduction of tiredness and fatigue and to normal muscle function [3]. Our guide to magnesium glycinate explains the main form it uses.
Frequently asked questions
What does magnesium do for women?
Magnesium contributes to a reduction of tiredness and fatigue, normal muscle function, normal psychological function and normal bones [3].
How much magnesium per day for a woman?
The NHS says women aged 19 to 64 need 270 mg a day. UK women get 224 mg a day from food on average [1][2].
Does magnesium help with PMS?
The evidence is mixed. Small trials found less bloating or better mood scores, but a larger trial and a 2025 review didn't find a clear benefit [5][7][8]. The NHS says there's not much evidence that supplements work for PMS [4].
Does magnesium help with period cramps?
A Cochrane review of three small trials found magnesium eased period pain more than placebo, but the best dose wasn't clear [9]. Heat, gentle exercise and painkillers are the NHS's first suggestions [10].
When should a woman take magnesium?
For general intake, take it at a time you'll remember each day. In the PMS trials, women took it daily through the cycle or from mid-cycle until their period [5][6].
Read more in our guide to when to take magnesium.
References
Every study here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We check it again at least every six months.
- NHS. Vitamins and minerals: others (magnesium and zinc sections). Page last reviewed 3 August 2020. Accessed 26 October 2026. nhs.uk
- Office for Health Improvement and Disparities (2025). National Diet and Nutrition Survey 2019 to 2023 (chapter 5 data, tables 5.41 and 5.62). Accessed 26 October 2026. gov.uk/government/statistics/national-diet-and-nutrition-survey-2019-to-2023
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register, spreadsheet of 19 May 2026. Accessed 26 October 2026. gov.uk
- NHS. PMS (premenstrual syndrome). Page last reviewed 18 June 2024. Accessed 26 October 2026. nhs.uk
- Walker AF, De Souza MC, Vickers MF, et al. (1998). Magnesium supplementation alleviates premenstrual symptoms of fluid retention. Journal of Women's Health 7(9): 1157–1165. PMID 9861593
- Facchinetti F, Borella P, Sances G, et al. (1991). Oral magnesium successfully relieves premenstrual mood changes. Obstetrics and Gynecology 78(2): 177–181. PMID 2067759
- Walker AF, De Souza MC, Marakis G, et al. (2002). Unexpected benefit of sorbitol placebo in Mg intervention study of premenstrual symptoms: implications for choice of placebo in RCTs. Medical Hypotheses 58(3): 213–220. PMID 12018972
- Robinson J, Ferreira A, Iacovou M, Kellow NJ (2025). Effect of nutritional interventions on the psychological symptoms of premenstrual syndrome in women of reproductive age: a systematic review of randomized controlled trials. Nutrition Reviews 83(2): 280–306. PMID 38684926
- Proctor ML, Murphy PA (2001). Herbal and dietary therapies for primary and secondary dysmenorrhoea. Cochrane Database of Systematic Reviews (3): CD002124. PMID 11687013
- NHS. Period pain. Page last reviewed 18 March 2026. Accessed 26 October 2026. nhs.uk
- Park H, Qin R, Smith TJ, et al. (2015). North Central Cancer Treatment Group N10C2 (Alliance): a double-blind placebo-controlled study of magnesium supplements to reduce menopausal hot flashes. Menopause 22(6): 627–632. PMID 25423327
- NHS. Osteoporosis. Page last reviewed 13 October 2022. Accessed 30 October 2026. nhs.uk
- Chang J, Yu D, Ji J, et al. (2020). The association between the concentration of serum magnesium and postmenopausal osteoporosis. Frontiers in Medicine 7: 381. PMID 32850896
