Horny Goat Weed (Epimedium): Evidence for Erectile Dysfunction, Libido, and Safety

Horny goat weed (Epimedium spp.) contains icariin, a PDE5 inhibitor similar to sildenafil but weaker. Traditional Chinese Medicine uses it for "kidney yang deficiency" (low libido, ED, fatigue, back pain).

Evidence

• ED (men): Small RCTs show modest improvement in mild-moderate ED (IIEF scores).
• Libido (women): One study reported improved desire in postmenopausal women.
• Bone/Osteoporosis: Icariin shows osteogenic effects in vitro/animal models.
• Antioxidant/anti-inflammatory: Preclinical data.

Safety & Interactions

• Common: nausea, dizziness, dry mouth, tachycardia.
• Contraindicated: bleeding disorders, anticoagulants, hormone-sensitive cancers, pregnancy.
• Interacts with: antihypertensives, nitrates, CYP3A4 substrates.

Regulation

Sold as supplement (DSHEA) in US—no FDA pre-market approval for efficacy, purity, or dose consistency. Quality varies widely.

Discuss with your physician before use, especially if on medications or with cardiovascular disease.