NutriStack
Black Cohosh and Estradiol, a caution.
Black cohosh (Cimicifuga racemosa) is used for menopausal symptoms and has mild estrogenic and serotonergic activity. Combining it with prescribed estradiol is rarely necessary and complicates side-effect attribution, including for rare liver-injury cases reported with black cohosh.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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At a glance
- Substances
- Black Cohosh and Estradiol
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. Black cohosh (Cimicifuga racemosa) is used for menopausal symptoms and has mild estrogenic and serotonergic activity. Combining it with prescribed estradiol is rarely necessary and complicates side-effect attribution, including for rare liver-injury cases reported with black cohosh.
Mechanism. Black cohosh has weak effects at estrogen and serotonin receptors and modulates dopamine; stacking with exogenous estradiol may amplify estrogenic effects on breast, endometrium, and clotting and adds an independent hepatotoxicity signal.
Recommendation. If you are already on prescribed estradiol for menopausal symptoms, adding black cohosh is generally not needed. If you decide to combine them, do so under clinician supervision and watch for jaundice, dark urine, or abdominal pain (signs of liver injury). Stop and seek care if these occur.
Sources (2)
- Basciani S, Porcaro G. Counteracting side effects of combined oral contraceptives through the administration of specific micronutrients. Eur Rev Med Pharmacol Sci. 2022;26(13):4846-4862. PMID 35856377
- Palmery M, Saraceno A, Vaiarelli A, Carlomagno G. Oral contraceptives and changes in nutritional requirements. Eur Rev Med Pharmacol Sci. 2013;17(13):1804-13. PMID 23852908
Stack Score
How this pair moves the number.
Effect on the composite score
If both Black Cohosh and Estradiol are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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