Randomised trial, 2000

Does St John's Wort help PMS symptoms?

One small study found a 49% reduction in symptom scores, but the researchers noted that natural symptom fluctuation and placebo effect probably explained the improvement. We cannot be confident the herb itself helped.

Early or limited evidence 19 women with PMS who completed the study (screened from 96 total)

What they did

96 women were screened for PMS, 25 were enrolled, and 19 completed the study taking St John's Wort. No control group was used.

What they found

The Daily Symptom Rating score fell by 49%. Women also showed improvements in anxiety and depression scores.

What it means for you

This result is unreliable without a control group. PMS naturally fluctuates and often improves on its own. The placebo effect is also strong for PMS. The authors suggested improvements likely came from these factors rather than the herb. Main limits: no control group, small sample.

49%

reduction in symptom score

women completed

women screened

About the study

Original title: St John's Wort and the premenstrual syndrome
Authors: John M. Grant
Journal: BJOG An International Journal of Obstetrics & Gynaecology
Year: 2000
Study design: Randomised trial
Participants: 96
What was tested: St John's Wort (Hypericum perforatum)
Read the paper: doi.org/10.1111/j.1471-0528.2000.tb11077.x

Topics

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