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Randomised trial, 2013

Does Shirazi thyme reduce premenstrual symptoms?

No. Both the herb and placebo reduced PMS symptoms by similar amounts, so the herb provided no extra benefit.

Moderate study design 75 college students with PMS

What they did

Double-blind randomized trial. 75 college students were divided into two groups. One received Zataria multiflora essence (20mg in 4 pearls daily for 2 menstrual cycles), the other placebo. Both groups tracked symptoms for 4 menstrual cycles total: 2 before and 2 during treatment.

What they found

Both groups showed a clear improvement in PMS symptoms after treatment began. Symptom frequency decreased over the cycles. However, there was no difference between the herb and placebo groups.

What it means for you

This herb did not work better than placebo for PMS. Both groups improved, likely due to natural improvement over time or placebo effect rather than the herb itself.

75

Total participants

38 and 37

Herb and placebo group sizes

About the study

Original title
Effects of Zataria Multi-Flora, Shirazi thyme, on the Severity of Premenstrual Syndrome
Authors
Sodouri M, Masoudi Alavi N, Fathizadeh N et al.
Journal
Nursing and midwifery studies
Year
2013
Study design
Randomised trial
Participants
37
What was tested
Zataria multiflora essence 20mg in 4 pearls daily for 2 menstrual cycles
Open access
Yes
Original abstract

Background: Premenstrual Syndrome (PMS) is a common problem in women. Zataria multiflora Boiss is a valuable plant. This herbal plant has been used in different conditions. Objectives: The study was performed to investigate the effects of Zataria multiflora Boiss to control PMS symptoms. Materials and methods: This study was a double-blinded, prospective randomized trial. The study population was the college students living in the dormitories of Isfahan University. Eighty-eight eligible students were randomly divided to intervention and control groups. Students completed the prospective record of the impact and severity of menstrual symptoms (PRISM) calendar including 30 PMS symptoms for four menstrual cycles (two cycles before, and two after the intervention). The intervention group received pearls containing 20 mg of Zataria multi-flora essence (four pearls each day) for two menstrual cycles, seven days before menstruation. The mean difference of PMS severity score between groups was analyzed with Mann-Whitney U test. The difference in frequency score of symptoms was analyzed using repeated-measure analysis of variance. Results: Thirty-eight students in intervention and 37 students in placebo group completed the study. The groups had no significant difference regarding the severity of PMS. Both groups showed a significant improvement in PMS severity score after the intervention. The repeated-measure analysis of variance showed that the frequency of symptoms decreased significantly in the cycles, but it was not different in intervention and placebo groups. Conclusions: Our findings did not support the use of Zataria multiflora Boiss in premenstrual syndrome.

Reproduced under CC-BY.

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