✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
⚠ ER+ breast cancer patient on tamoxifen using red clover — contraindicated [1]
⚠ Patient not responding to isoflavones — may be equol non-producer (~70% of Western women) [2]
⚠ Patient on warfarin using red clover — coumarin content; monitor INR [1]
⚠ Patient confusing red clover with soy isoflavones — different isoflavone profiles [1]
🥗 Food first — build your daily Typical 40–80 mg isoflavones
Check the foods you regularly eat — the bar fills toward your daily target.
Red clover sprouts (100 g)30 mg isoflavones (approximate)
Red clover tea (1 cup)10 mg isoflavones (approximate)
Check your regular foods above
🔬 Lab interpreter
Recommended test
No routine monitoring for short-term use
No routine monitoring for short-term use
Reference range / target
N/A
N/A
When to test
N/A
N/A
Consider endometrial thickness monitoring for long-term use (>12 months) [1].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Red clover isoflavones have mixed meta-analytic results for hot flashes — likely because only ~30% of Western women produce equol (active metabolite). The critical clinical issue: contraindicated in ER+ breast cancer patients on tamoxifen/AI therapy due to phytoestrogen activity, despite some experts arguing ERβ selectivity may be protective. Coumarin content adds a theoretical warfarin interaction [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Avoid. Phytoestrogen activity may interfere with fetal hormonal development [1].
👦 Pediatric: See guidance
Avoid in children due to estrogenic activity [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: With food. Once or twice daily [1].
💊 With food: No specific requirement [1].
🚫 Avoid: In ER+ breast cancer patients. During pregnancy. Concurrent with tamoxifen/AI therapy. Without discussing with oncologist if any breast cancer history [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Red clover isoflavone extract (Promensil®)', 'preferred', 'Standardized to 40–80 mg total isoflavones/day. Most clinical evidence [1].'] | Standard | Check label | |
| ['Red clover flower tea', 'traditional', "1–3 cups/day. Low isoflavone content. Traditional 'blood cleanser' [1]."] | Standard | Check label | |
| ['Red clover tincture', 'traditional', '2–4 mL TID [1].'] | Standard | Check label |
3 Common questions
Is red clover safe for breast cancer survivors? ▼
This is controversial. Red clover isoflavones are phytoestrogens that bind estrogen receptors. While epidemiological data have not shown increased breast cancer risk, and some experts consider phytoestrogens to be weakly protective (ERβ selectivity), the safety in ER-positive breast cancer survivors on tamoxifen/AI therapy is NOT established. Most oncologists advise against red clover in this population [1].
Red clover vs soy isoflavones — what's the difference? ▼
Different isoflavone profiles. Red clover contains biochanin A and formononetin (methylated isoflavones, metabolized to genistein and daidzein). Soy contains genistein and daidzein directly. Red clover provides higher total isoflavone exposure per dose. Whether this translates to clinical differences is debated [1].
Why are hot flash results so mixed? ▼
Key factor: equol production. Only ~30% of Western women can convert daidzein to equol (a more potent phytoestrogen) via gut bacteria. Equol producers likely respond better to isoflavone supplementation. Studies that don't stratify by equol status show diluted effects [2].
Does red clover contain coumarin? ▼
Yes, red clover contains small amounts of coumarin compounds, including the potential to form dicoumarol if fermented/spoiled (which caused bleeding in livestock historically). Properly manufactured supplements have minimal coumarin content, but the interaction with warfarin is theoretically possible [1].
4 Clinical evidence
Strong
No unambiguous strong evidence. Meta-analyses are conflicting [2]. HIGH
Moderate
Hot flashes: a meta-analysis of 6 RCTs found red clover isoflavones reduced hot flash frequency by approximately 1.5 episodes/day vs placebo (statistically significant but modest). However, another meta-analysis found no significant effect — results are inconsistent across analyses, likely due to population heterogeneity and equol-producer status [2]. Bone density: 1 RCT (n=205) found 40 mg/day red clover isoflavones slowed lumbar spine bone loss in postmenopausal women over 12 months [1]. Lipids: modest TC and LDL reduction in some trials [1]. MODERATE
Insufficient
Breast cancer risk: cohort studies suggest no increased risk, but RCT data in breast cancer survivors are insufficient [1]. Cognitive function in menopause: 1 pilot study [1]. Skin aging: 1 small RCT showed improved skin hydration and thickness [1]. Prostate cancer: preclinical isoflavone data; no clinical trials [1]. LOW
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Hormone-sensitive cancers (breast, uterine, ovarian) — phytoestrogen activity
✕ Pregnancy and lactation
Relative
⚠ Anticoagulants — contains coumarins; bleeding risk
⚠ Tamoxifen/hormonal therapy — may interfere
⚠ Discontinue before surgery
🚩 Red flags
● ER+ breast cancer survivor using red clover — discuss with oncologist [1]
● Patient experiencing breast tenderness — estrogenic effect; assess [1]
● Patient on warfarin — coumarin content; check INR [1]
6 Interactions
Drug interactions
Tamoxifen / Aromatase inhibitors Major
Mechanism: Phytoestrogen ER binding opposes anti-estrogen therapy [1].
Effect: Theoretical reduction in anti-estrogen efficacy [1].
Action: Contraindicated in ER+ breast cancer on endocrine therapy [1].
Warfarin Moderate
Mechanism: Coumarin content in red clover [1].
Effect: Theoretical additive anticoagulation [1].
Action: Monitor INR [1].
Supplement synergies
Black Cohosh · 40 mg RC isoflavones + 20–40 mg black cohosh extract
Complementary menopausal symptom mechanisms: red clover (phytoestrogen) + black cohosh (non-estrogenic, serotonergic). Different MOA avoids estrogenic stacking [1].
Complementary menopausal symptom mechanisms: red clover (phytoestrogen) + black cohosh (non-estrogenic, serotonergic). Different MOA avoids estrogenic stacking [1].
7 Regulatory
European Union (EMA): Traditional herbal medicinal product for menopausal complaints (vasomotor symptoms) [1].
United States (FDA): Available as dietary supplement. No FDA-approved claims [1].
Australia (TGA): Listed complementary medicine for menopausal symptom relief [1].
8 US supplement products
141
on-market products containing Red Clover (NIH DSLD)
Brands carrying Red Clover (81)
Click a brand to see its Red Clover products.
9 Frequently paired with
10 References (4)
[1]Coon JT, et al. Trifolium pratense isoflavones in the treatment of menopausal hot flushes: a systematic review and meta-analysis. Phytomedicine. 2007;14(2-3):153-159. doi:10.1016/j.phymed.2006.12.009 META-ANALYSIS Accessed: 2026-05-29
[2]Lethaby A, et al. Phytoestrogens for menopausal vasomotor symptoms. Cochrane Database Syst Rev. 2013;(12):CD001395. doi:10.1002/14651858.CD001395.pub4 REVIEW Accessed: 2026-05-29
[3]Atkinson C, et al. The effects of isoflavone phytoestrogens on bone: preliminary results from a large randomized controlled trial. Endocr Rev. 2004;25(1):1-36. RCT Accessed: 2026-05-29
[4]Myers SP, Vigar V. Effects of a standardised extract of Trifolium pratense (Promensil) at a dosage of 80mg in the treatment of menopausal hot flushes: a systematic review and meta-analysis. Phytomedicine. 2017;24:141-147. doi:10.1016/j.phymed.2016.12.003 META-ANALYSIS Accessed: 2026-05-29
11 Related articles
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12 Cite this page
Vancouver: Pkhakadze G. Red Clover — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Jun 02]. Available from: https://supplement.ge/ingredients/red-clover/
APA 7th: Pkhakadze, G. (2026). Red Clover — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/red-clover/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: December 2026
References: 4 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Red Clover — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/red-clover/ CC BY 4.0.
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Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG