--- title: Does S-equol supplement help reduce premenstrual symptoms? | Niyora description: S-equol showed only a small benefit for premenstrual symptoms, with improvement related to gut bacteria composition. url: https://niyora.com/research/papers/evaluation-of-a-natural-s-equol-supplement-in-treating-premenstrual-symptoms-and-2022/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Does S-equol supplement help reduce premenstrual symptoms? Non-randomised trial, 2022 # Does S-equol supplement help reduce premenstrual symptoms? S-equol showed only a small benefit for premenstrual symptoms, with improvement related to gut bacteria composition. Early or limited evidence 20 women with premenstrual symptoms who do not naturally produce equol ## What they did 20 women with premenstrual symptoms (who don't naturally produce equol from soy) took an S-equol supplement for two menstrual cycles. Symptoms were measured before and during treatment using the Daily Record of Severity of Problems questionnaire. Researchers also analyzed their gut bacteria before treatment. ## What they found Only 10.5% of women showed at least 50% improvement in symptoms. However, overall analysis showed improvement in symptom scores and in four key PMDD symptoms. Women whose improvement was greatest had higher Bifidobacterium and lower Clostridium cluster IV bacteria in their gut. ## What it means for you S-equol supplements may help some women with premenstrual symptoms, but only a small number respond well. The gut bacteria may play a role in whether the supplement works. This is a very small pilot study with no control group, so much more research is needed. 20 Women in study 10.5% With at least 50% improvement in symptoms 4 Core PMDD symptoms improved ## About the study Original title Evaluation of a natural S-equol supplement in treating premenstrual symptoms and the effect of the gut microbiota: An open-label pilot study Authors Takeda T, Chiba Y Journal Neuropsychopharmacology reports Year 2022 Study design Non-randomised trial What was tested Oral S-equol supplement for two menstrual cycles Open access Yes Read the paper [doi.org/10.1002/npr2.12234](https://doi.org/10.1002/npr2.12234) Original abstract Aim: Premenstrual syndrome causes disturbances in many women's daily activities. Isoflavones might cause changes in the estrogen cycle by their selective estrogen receptor modulator-like activities. Equol, which is a metabolite of a soy isoflavone, has greater biological activity than other soy isoflavones. In this preliminary study, we aimed to examine the effect of a natural S-equol supplement (SE5-OH) on premenstrual symptoms. The gut microbiota has recently been suggested to play an important role in brain function in psychiatric disease, such as depression. Therefore, we further aimed to evaluate the relationship of the effect of SE5-OH and the gut microbiota at preintervention. Methods: Twenty women who showed premenstrual symptoms and were nonequol producers were enrolled in an open-label, single-arm, clinical study in which they received oral SE5-OH for two period cycles. The Daily Record of Severity of Problems (DRSP) total score was evaluated during the intervention cycles. Before taking SE5-OH, fecal samples were obtained and subjected to terminal restriction fragment length polymorphism analysis. Results: The response rate to treatment (≥50% reduction from baseline in the DRSP total score) was 10.5%. Post hoc analysis showed a significant improvement in the change in the DRSP total score (P = .008) and DRSP scores for four core premenstrual dysphoric disorder symptoms. Multiple regression analysis showed that the percentage improvement of the DRSP total score was positively related to Bifidobacterium and negatively related to Clostridium cluster IV. Conclusion: SE5-OH supplementation may be an acceptable treatment for premenstrual symptoms. The intestinal microbiota may have an effect on SE5-OH. Reproduced under CC-BY. ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Premenstrual dysphoric disorder (PMDD)](https://niyora.com/research/topics/condition-pmdd/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[Diet and nutrition](https://niyora.com/research/topics/treatment-diet/)[IBS and gut symptoms](https://niyora.com/research/topics/comorbidity-ibs-gi/) 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 Systematic review, 2025 How common are PMS, PMDD, and painful periods in nursing students, and do they affect their schooling? Review, 2001 What causes PMS and PMDD, and how are they treated? Randomised trial, 2024 Does a banana drink with egg white reduce PMDD symptoms and improve mood? Survey study, 2023 What factors make some women more likely to have PMS or PMDD? Survey study, 2019 What lifestyle and sleep habits are linked to PMS in teenage girls? Case-control study, 2018 Do women with PMDD crave different foods than healthy women? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗