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Head-to-head evidence comparison — which supplement is right for you?
Spearmint wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
11 of 13 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (2)
Outcomes where both Soy Isoflavones and Spearmint have evidence — compare verdict strength side-by-side.
40-80mg isoflavones daily
Divided doses with meals, Consistent daily timing
Standardized soy isoflavone extract
900 mg/day of standardized spearmint extract (or 2 cups of spearmint herbal tea daily)
Morning with breakfast, Evening with dinner (split dosing mirrors clinical trial protocols)
Standardized aqueous extract (high-rosmarinic acid)
4-12 weeks
6-12 months
8-12 weeks
Initial use
2–4 weeks
4–12 weeks
4–8 weeks
8–16 weeks
Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials
Critical reviews in food science and nutrition (2020) · Meta analysis · n=5313
Soy isoflavones prevent osteoporosis-related bone loss in any weight status or treatment duration.
Effect of Soy Isoflavones on Measures of Estrogenicity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Advances in nutrition (Bethesda, Md.) (2025) · Meta analysis · n=3285
Addressing public health concerns may promote soy foods as high-quality plant protein sources with low environmental impact and cost, particularly benefiting postmenopausal women and aligning with sustainable dietary patterns and guidelines.
Effects of soy isoflavones on menopausal symptoms in perimenopausal women: a systematic review and meta-analysis
PeerJ (2025) · Meta analysis · n=533
In October 2024, we screened 2,099 articles, of which 12 were eligible for meta-analysis, and found that soy isoflavones were effective for treating menopausal symptoms (seven studies, 533 participants, Hedges' g = -0.25, 95% CI [-0.42 to -0.08], p = 0.00).
An evidence-based systematic review of spearmint by the natural standard research collaboration.
Journal of dietary supplements (2010) · Systematic review
Spearmint (Mentha spicata) has demonstrated anti-androgenic, antimicrobial, and antioxidant properties in available literature.
A systematic review of the efficacy of alternative medicine in the treatment of nausea and vomiting of pregnancy.
Journal of obstetrics and gynaecology : the journal of the Institute of Obstetrics and Gynaecology (2020) · Systematic review
Spearmint syrup was identified as one of several herbal alternatives showing efficacy for mild-to-moderate pregnancy nausea and vomiting.
Spearmint herbal tea has significant anti-androgen effects in polycystic ovarian syndrome. A randomized controlled trial.
Phytotherapy research : PTR (2010) · Rct · n=42
Forty-one of 42 patients completed this 30-day RCT comparing spearmint tea twice daily to placebo herbal tea.
Meta-analysis of 533 participants showed effectiveness for menopausal symptoms. Effect size appears modest and heterogeneity was noted across studies. Individual response varies significantly.
Based on 2 RCTs in women with PCOS/hirsutism. Tea form equivalent to ~400-600mg extract. Effects specific to women; men should avoid chronic high-dose use.
AI-estimated from published studies. Interpret as directional guidance.
Spearmint has a higher evidence score (6.2/10 vs 6/10) and wins in 2 of 3 categories.
For estrogen & progesterone balance, Spearmint has a higher relevance score (88 vs 85).
No known interactions between Soy Isoflavones and Spearmint have been documented in our database. However, always consult a healthcare provider before combining supplements.