Randomised trial, 1998
Does 200 mg magnesium daily help premenstrual symptoms?
Yes, but only for fluid retention symptoms like bloating and breast swelling, and only during the second month of treatment.
What they did
Double-blind placebo-controlled crossover study with 38 women. Each woman took either 200 mg magnesium or placebo daily for 2 menstrual cycles, then switched. They tracked 22 symptoms daily on a 4-point scale, including anxiety, cravings, depression, fluid retention, and other symptoms.
What they found
In the first month, magnesium made no difference compared with placebo. In the second month, magnesium significantly reduced fluid retention symptoms (weight gain, swelling of extremities, breast tenderness, and abdominal bloating) compared with placebo (p=0.009). Urine testing confirmed women were taking the magnesium.
What it means for you
Magnesium 200 mg may help specifically with fluid retention symptoms of PMS, but requires 2 cycles of treatment to work. It did not help other PMS symptoms like mood or cravings. This was a small study.
38
women
200 mg
daily magnesium dose
p=0.009
statistical significance for fluid retention in month 2
About the study
- Original title
- Magnesium supplementation alleviates premenstrual symptoms of fluid retention
- Authors
- Walker AF, De Souza MC, Vickers MF et al.
- Journal
- Journal of women's health
- Year
- 1998
- Study design
- Randomised trial
- Participants
- 38
- What was tested
- 200 mg magnesium (as MgO) daily vs placebo for 2 menstrual cycles
- Open access
- Yes
- Read the paper
- doi.org/10.1089/jwh.1998.7.1157
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