Epimedium Herb — Safety & Interactions
Yin Yang Huo · Herba Epimedii
Use with caution. Practitioner review recommended before use.
Contraindications
- Yin deficiency with Heat signs (night sweats, afternoon fever, dry mouth, red tongue without coat)
- Excess Heat patterns
- Hormone-sensitive conditions (breast cancer, uterine cancer, endometriosis) — estrogenic activity
Cautions
- Standard dose 6–15g decoction
- Prolonged use may induce CYP3A4 via pregnane X receptor activation — potential reduced efficacy of CYP3A4-metabolised drugs (immunosuppressants, statins, antivirals) with extended use
- Aromatase inhibitors: icariin promotes aromatase (CYP19) activity — may reduce efficacy of anastrozole, exemestane, and letrozole in breast cancer treatment
- PDE5 inhibitors (sildenafil, tadalafil, vardenafil): additive pharmacodynamic effect; avoid concurrent use — herb-drug interaction documented in animal PK study (PMC6270200)
Drug Interactions
| Drug Class / Substrate | Mechanism | Severity | Source |
|---|---|---|---|
| Aromatase inhibitors (anastrozole, exemestane, letrozole): icariin promotes aromatase activity — potential reduction in drug efficacy in estrogen-sensitive cancer treatment | |||
| PDE5 inhibitors (sildenafil, tadalafil): pharmacodynamic additive effect via shared cGMP pathway; potential for enhanced hypotensive effect | |||
| CYP3A4 substrates: prolonged Epimedium use may induce CYP3A4 — reduced plasma levels of narrow-therapeutic-index CYP3A4 drugs possible with extended use | |||
This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.