Do supplements help PMS? What the evidence actually says
Some supplements may help PMS, but the evidence is modest. Calcium has the best trial support, with 1,200 mg a day easing symptoms in a large study. Vitamin B6 and magnesium have some positive but low-quality evidence, and chasteberry looks promising but trials are at high risk of bias. Ask a pharmacist before starting any, especially if you take other medicines.
The evidence, graded
| Supplement | Dose studied | Evidence | What it may help |
|---|---|---|---|
| Calcium | 1,200 mg elemental calcium a day (as calcium carbonate) | Moderate: one large randomized trial plus smaller ones | Overall PMS, including mood, bloating, cravings, pain |
| Vitamin B6 | Up to 100 mg a day in trials | Low: a 1999 review found benefit but mostly poor-quality trials | Overall symptoms and low mood |
| Magnesium | 200 mg a day or more in small trials | Low: small, older studies | Bloating, fluid retention, mood |
| Chasteberry (Vitex agnus-castus) | Standardized extracts, usually daily | Uncertain: positive trials, but high risk of bias and publication bias | Breast tenderness, overall PMS |
| Vitamin D | Various | Very low: mixed observational data | Unclear |
| Evening primrose oil | Various | Very low: not shown to beat placebo | Unlikely to help |
Supplements tend to take two to three cycles to show any effect, so judge them over months, not days. And because PMS symptoms vary naturally, it helps to rate your symptoms daily before and after starting, rather than relying on how you remember feeling.
Calcium
In a trial of 466 women with moderate to severe PMS, 1,200 mg of calcium a day reduced total symptom scores by 48% by the third cycle, compared with 30% on placebo. Food counts too: dairy, fortified plant milks, tofu and leafy greens. Too much calcium from supplements can cause constipation and, in some people, kidney stones, and it can reduce absorption of thyroid medicine and some antibiotics, so space them apart.
Vitamin B6
B6 may help mood-related PMS, but the trials are weak. Long-term use of high doses can damage nerves, causing numbness or tingling in the hands and feet. The US upper limit for adults is 100 mg a day, and UK advice is lower, at no more than 10 mg a day from supplements unless a doctor advises more. Don't exceed the label.
Magnesium
Small trials found magnesium eased fluid retention and premenstrual mood changes, sometimes only after two months. The usual adult upper limit for supplemental magnesium is 350 mg a day; more often causes diarrhea. See our full page on magnesium for PMS.
Chasteberry
A 2017 meta-analysis found a large effect for chasteberry, but the authors couldn't draw firm conclusions because most trials were at high risk of bias. It's generally well tolerated short term, but it isn't recommended in pregnancy or breastfeeding, or with hormone-sensitive conditions. Because it may act on hormones and dopamine, check with a doctor if you use hormonal contraception or take medicines that affect dopamine.
Ask a pharmacist or doctor, especially if you're pregnant or trying to conceive, have kidney disease, or take other medicines (including thyroid medicine, antibiotics, diuretics or psychiatric medicines). Supplements aren't regulated like medicines, so quality varies. If PMS is severe or you feel hopeless, see a doctor: proven treatments exist. If you ever think about harming yourself, call your local emergency number or, in the US, call or text 988.
What works as well as any pill
Regular aerobic exercise, steady sleep, regular meals and cutting back on alcohol have reasonable evidence for PMS and no side effects. For severe PMS or PMDD, SSRIs and some hormonal treatments have far stronger evidence than any supplement. See PMS coping tips.
Frequently asked questions
What is the best supplement for PMS?
Calcium has the strongest evidence, from a large randomized trial. Others have weaker or less certain evidence.
Can I take calcium, magnesium and B6 together?
Many people do, but check total doses and interactions with a pharmacist first, especially if you take other medicines.
How long do PMS supplements take to work?
Usually two to three cycles. Track symptoms daily to see if there's a real change.
Do supplements help PMDD?
Evidence for PMDD is thin. SSRIs and some hormonal treatments work far better. See PMDD treatment.
Sources
- Thys-Jacobs S et al. Calcium carbonate and the premenstrual syndrome. Am J Obstet Gynecol (1998)
- Wyatt KM et al. Efficacy of vitamin B-6 in the treatment of premenstrual syndrome: systematic review. BMJ (1999)
- Verkaik S et al. The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis. Am J Obstet Gynecol (2017)
- NIH Office of Dietary Supplements: Vitamin B6 Fact Sheet for Health Professionals
- NCCIH: Chasteberry
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Does magnesium help PMS?Magnesium for PMS: small trials suggest it may ease bloating, mood changes and cramps. Doses studied, safe limits, side effects and interactions to know.
How to deal with PMS at work and at home: practical coping tipsHow to deal with PMS in real life: plan around your cycle at work, talk to the people you live with, manage mood in the moment, and know when to get help.
PMDD treatment: options to discuss with your doctorPMDD treatment explained: SSRIs including luteal-phase dosing, the drospirenone pill, CBT, GnRH options and lifestyle steps, plus how to find the right care.
What causes PMS?What causes PMS? Not abnormal hormones, but some brains reacting more strongly to the normal rise and fall of estrogen and progesterone. What makes it worse.PMS symptom diary: what to track for your doctorHow to keep a PMS symptom diary doctors can use: the daily items, the 1 to 6 rating scale, how long to track, and how to read the chart before your visit.