Objective: To investigate whether Hypericum perforatum could relieve symptoms of premenstrual syndrome in a small group of women in order to establish a hypothesis and to test methods for conducting a future randomised controlled trial.
Design: Prospective, open, uncontrolled, observational study.
Setting: Department of Complementary Medicine, University of Exeter.
Population: Nineteen women with premenstrual syndrome who were in otherwise good physical and mental health and not taking other treatments for premenstrual syndrome.
Method: Volunteers underwent a preliminary screening interview, completed Daily Symptom Ratings for one cycle, and attended a medical screening visit before being diagnosed with premenstrual syndrome. Participants took hypericum tablets for two complete menstrual cycles (1 x 300 mg hypericum extract per day standardised to 900 microg hypericin).
Main outcome measures: Symptoms were rated daily throughout the trial using a validated measure. The Hospital Anxiety and Depression scale and modified Social Adjustment Scale were administered at baseline and after one and two cycles of treatment.
Results: There were significant reductions in all outcome measures. The degree of improvement in overall premenstrual syndrome scores between baseline and the end of the trial was 51%, with over two-thirds of the sample demonstrating at least a 50% decrease in symptom severity. Tolerance and compliance with the treatment were encouraging.
Conclusion: The results of this pilot study suggest that there is scope for conducting a randomised, placebo-controlled, double-blind trial to investigate the value of hypericum as a treatment for premenstrual syndrome.