Is horny goat weed a safe and effective treatment for erectile dysfunction or other conditions?

Horny Goat Weed for Erectile Dysfunction and Other Conditions

Horny goat weed should be discontinued at least 2 weeks before any surgical procedure and is not recommended for erectile dysfunction treatment due to lack of proven efficacy, potential cardiovascular risks including vasodilation and hypotension, and documented adverse effects including severe muscle spasms and elevated creatine kinase. 1

Perioperative Safety Concerns

The Society for Perioperative Assessment and Quality Improvement (SPAQI) explicitly recommends holding horny goat weed for 2 weeks before surgery due to its mechanism of causing vasodilation, possibly through blocking calcium channels or catecholamine blockade. 1 This vasodilatory effect poses significant risk for:

• Intraoperative hypotension when combined with anesthetic agents 1
• Unpredictable blood pressure control during the perioperative period 1
• Potential interaction with cardiovascular medications 1

Lack of Evidence for Erectile Dysfunction

The American Urological Association guidelines for erectile dysfunction management do not include horny goat weed as a recommended treatment option. 1 The AUA explicitly states that first-line therapy for ED should be oral PDE5 inhibitors (sildenafil, tadalafil, vardenafil) unless contraindicated, followed by stepwise progression to intraurethral alprostadil, intracavernous injections, vacuum erection devices, and penile prosthesis. 1

A systematic review of popular male supplements found that 68% of ingredients, including horny goat weed, received C or D grades for contradicting, negative, or lacking evidence. 2 Critically, no whole supplement products containing horny goat weed have published randomized controlled trial evidence demonstrating efficacy for erectile dysfunction. 2

Documented Adverse Effects

Severe Toxicity Case Report

A 2025 case report documented a 33-year-old man who developed:

• Severe muscle spasms lasting 10 hours requiring emergency department presentation 3
• Elevated creatine kinase (CK) requiring hospital admission 3
• Elevated creatinine indicating potential kidney involvement 3
• Symptoms began one month after starting the supplement and resolved only after discontinuation 3

Cardiovascular Risks

The vasodilatory mechanism of horny goat weed creates particular concern for patients with:

• Pre-existing cardiovascular disease 1
• Concurrent use of antihypertensive medications 1
• Patients taking nitrates (absolute contraindication due to potential severe hypotension) 1

Limited Preclinical Evidence Does Not Support Clinical Use

While animal studies have shown that icariin (the active component) may have neurotrophic effects and PDE5 inhibitory properties in rats with cavernous nerve injury 4, and potential cardiovascular protective effects in laboratory settings 5, these findings:

• Have not been validated in human clinical trials 2
• Do not establish safety or efficacy in humans 4
• Cannot justify clinical use given documented adverse effects 3

Clinical Recommendation Algorithm

For patients currently taking horny goat weed:

1. Discontinue immediately if surgery is planned within 2 weeks 1
2. Counsel regarding lack of proven efficacy for erectile dysfunction 2
3. Screen for adverse effects including muscle spasms, elevated CK, and cardiovascular symptoms 3
4. Transition to evidence-based ED therapies (PDE5 inhibitors as first-line) 1

For patients asking about horny goat weed:

1. Inform them it is not recommended by the American Urological Association 1
2. Explain documented risks including vasodilation, muscle toxicity, and lack of quality control in supplements 1, 3
3. Offer FDA-approved PDE5 inhibitors as first-line therapy with proven efficacy and safety profiles 1

Common Pitfalls to Avoid

• Do not assume herbal supplements are safe simply because they are "natural" - horny goat weed has documented serious adverse effects 3
• Do not fail to ask about supplement use in preoperative assessments, as patients may not volunteer this information 1, 3
• Do not delay proven ED treatments while patients experiment with unproven supplements 1, 2
• Do not underestimate cardiovascular risks in patients with multiple cardiac risk factors who use vasodilatory supplements 1