Last verified: 17 days ago
Horny Goat Weed
Also known as: Epimedium, Herba Epimedii, Yinyanghuo, Icariin, Epimedium sagittatum, Epimedium grandiflorum
Evidence under review. — Not yet rated
Traditional herb with weak human evidence for sexual health; animal data only for most claimed benefits.
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What it does
Horny Goat Weed is a traditional Chinese medicinal plant whose active compound, icariin, has been studied mainly in animals. In rat studies, icariin showed potential to improve erectile function...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose
What the Science Says
Horny Goat Weed is a traditional Chinese medicinal plant whose active compound, icariin, has been studied mainly in animals. In rat studies, icariin showed potential to improve erectile function by inhibiting PDE5 (the same enzyme targeted by Viagra) and may support nerve tissue health. Animal studies also suggest its active compound may help preserve bone density and reduce atherosclerosis progression, but none of these effects have been confirmed in human clinical trials.
What It Doesn't Do
Not proven to treat erectile dysfunction in humans. No solid clinical trial evidence it boosts testosterone. Don't expect Viagra-like results — the human data simply isn't there. Online reviews are largely unreliable; one analysis found a 77–90% drop in positive reviews after filtering fake ones. Not a proven bone-loss treatment in people.
Evidence-Based Benefits
Icariin improved erectile function in nerve-injured rats by inhibiting PDE5 and supporting nerve tissue.
Weak EvidenceEffective at: 1–10 mg/kg daily in rats
Supporting studies (click to view on PubMed):
Icariin increased bone mineral density and improved bone structure in ovariectomized rats.
Weak EvidenceEffective at: No human dose established
Supporting studies (click to view on PubMed):
Icariin reduced arterial plaque lesion area in mice by lowering inflammatory macrophage activity.
Weak EvidenceEffective at: 30–60 mg/kg daily in mice
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Unknown — no human pharmacokinetic data in the provided studies. Animal studies use icariin as a purified extract, which may differ significantly from whole-herb supplements sold to consumers.
Red Flags to Watch For
- Documented case of severe muscle spasms and elevated creatine kinase (muscle damage marker) in a 33-year-old man after use
- Documented case of new-onset psychosis in a Parkinson's patient after use
- Sold in products containing up to 33 mixed ingredients, making it impossible to attribute any effect to horny goat weed specifically
- Online reviews for ED supplements containing this ingredient were found to be overwhelmingly fake or unreliable
- No standardized dosing or purity regulation — what's on the label may not match what's in the bottle
Products Containing Horny Goat Weed
See how Horny Goat Weed is used in these analyzed products:
Frequently Asked Questions
What does Horny Goat Weed do?
Traditional herb with weak human evidence for sexual health; animal data only for most claimed benefits.
What is the effective dose of Horny Goat Weed?
No established dose
Is Horny Goat Weed safe?
Documented case of severe muscle spasms and elevated creatine kinase (muscle damage marker) in a 33-year-old man after use
What doesn't Horny Goat Weed do?
Not proven to treat erectile dysfunction in humans.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25