Estradiol and Red Clover: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Estradiol
Red Clover
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Altered estrogenic effects or increased side effects
Interaction Deep Dive
Red clover isoflavones have affinity for estradiol-alpha and -beta receptors and may act as both agonists and antagonists12. Red clover may enhance the estrogenic effects of estrogens 34.
Why it happens (mechanism)
Red clover extract may act as an estrogen agonist or antagonist, and may have antiprogestin effects
Common questions
Can I take Estradiol and Red Clover together?
Altered estrogenic effects or increased side effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Estradiol and Red Clover interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Estradiol or Red Clover need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- Nelsen J, Barrette E, Tsouronix C, et al: Red clover (Trifolium pratense) monograph: A clinical decision support tool. J Herbal Pharmacotherapy 2002; 2(3):49-72. PubMed
- Zava DT, Dollbaum CM, & Blen M: Estrogen and progestin bioactivity of foods, herbs, and spices. PSEBM 1998; 217(3):369-378. DOI
- Kowalak JP & Mills EJKowalak JP & Mills EJ: Professional Guide to Complementary and Alternative Therapies, Springhouse Co, Springhouse, PA, 2001.
- Newall C, Anderson L, & Phillipson JNewall C, Anderson L, & Phillipson J: Herbal Medicines: A Guide for Health-Care Professionals, The Pharmaceutical Press, London, England, 1996.
Keep reading about Estradiol
Keep reading about Red Clover
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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