--- title: Does Shirazi thyme reduce premenstrual symptoms? | Niyora description: No. Both the herb and placebo reduced PMS symptoms by similar amounts, so the herb provided no extra benefit. url: https://niyora.com/research/papers/effects-of-zataria-multi-flora-shirazi-thyme-on-the-severity-of-premenstrual-2013/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Does Shirazi thyme reduce premenstrual symptoms? 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 Read the paper [doi.org/10.5812/nms.13709](https://doi.org/10.5812/nms.13709) 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. ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Other herbal medicine](https://niyora.com/research/topics/treatment-herbal-other/)[Students and academic performance](https://niyora.com/research/topics/life-area-education/) 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. ## Related studies Randomised trial, 2025 Which is more effective for PMS - Vitagnus, soy, or both together? Randomised trial, 2026 Can propolis and fennelin reduce PMS symptoms? Survey study, 2026 How common is PMDD among female medical students and what triggers it? Randomised trial, 2024 Does a herbal soft gel capsule with three oils reduce PMS symptoms? Randomised trial, 2021 Does nigella sativa oil reduce PMS symptoms? Randomised trial, 2020 Does anise reduce PMS symptoms? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗