---
title: Does St John's Wort help PMS symptoms? | Niyora
description: One small study found a 49% reduction in symptom scores, but the researchers noted that natural symptom fluctuation and placebo effect probably explained the
url: https://niyora.com/research/papers/st-john-s-wort-and-the-premenstrual-syndrome-2000/
---

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- Does St John's Wort help PMS symptoms?

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

19

women completed

96

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](https://doi.org/10.1111/j.1471-0528.2000.tb11077.x)

## Topics

[Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[Pain and headache](https://niyora.com/research/topics/symptom-pain/)[Other herbal medicine](https://niyora.com/research/topics/treatment-herbal-other/)

Research tells you what helps on average. Niyora helps on the day it hits.

Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor.

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