Randomised trial, 2000
Can the herb St John's Wort (Hypericum perforatum) ease PMS symptoms?
In this small early-stage study, women's PMS symptoms improved a lot while taking St John's Wort, but because there was no placebo group, we cannot be sure the herb itself caused the improvement.
What they did
Researchers gave 19 women with PMS a daily St John's Wort tablet (300 mg extract, standardised to 900 microg hypericin) for two full menstrual cycles. Everyone knew they were taking the real treatment (no placebo or control group). Symptoms were rated every day, and anxiety, depression and social functioning were measured at the start and after one and two cycles.
What they found
All the symptom measures improved significantly. Overall PMS symptom scores dropped by 51% from the start of the trial to the end, and more than two-thirds of the women had at least a 50% reduction in symptom severity. Women tolerated the tablets well and stuck with the treatment.
What it means for you
This was a small, open pilot study with no placebo group, so the improvement could be partly or wholly a placebo effect, not proof that St John's Wort works. The authors say it only justifies doing a proper randomised, placebo-controlled trial next, not using it as a confirmed PMS treatment.
19
Women in study
51%
Reduction in PMS symptom scores
>2/3
Women with at least 50% symptom reduction
About the study
- Original title
- A pilot study of Hypericum perforatum for the treatment of premenstrual syndrome
- Authors
- Stevinson C, Ernst E
- Journal
- BJOG : an international journal of obstetrics and gynaecology
- Year
- 2000
- Study design
- Randomised trial
- What was tested
- St John's Wort (Hypericum perforatum) tablets, 300 mg extract standardised to 900 microg hypericin per day, taken for two menstrual cycles.
- Read the paper
- doi.org/10.1111/j.1471-0528.2000.tb11085.x
Topics
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