What is Horny Goat Weed?
Horny goat weed is a leafy plant that is native to Asia and the Mediterranean region. It is also known as Epimedium and Yin Yan Huo.
Horny goat weed has a long history of use in traditional Chinese medicine.
Why Do People Use Horny Goat Weed?
1) Erectile Dysfunction and Sexual Dysfunction in Women
According to folklore, horny goat weed's reputed aphrodisiac qualities were discovered when a Chinese goat herder noticed increased sexual activity in his flock after they ingested the weed.
Animal studies indicate that horny goat weed may work by increasing nitric oxide levels, which relaxes smooth muscle and lets more blood flow to the penis or clitoris.
Horny goat weed also appears to act by inhibiting the PDE-5 enzyme, which is the same way that the popular drug Viagra works.
Some evidence suggests horny goat weed may modulate levels of the hormones cortisol, testosterone, and thyroid hormone, bringing low levels back to normal.
A study tested the estrogenic activity of 32 herbs used for menopause. Epimedium brevicornum, was one of the highest estrogenic activity.
There isn't enough information on horny goat weed to safely recommend it for erectile dysfunction or menopause.
In one study, epimedium koreanum was found to cause significant inhibition of the cholinesterase enzyme. This can theoretically increase the risk of loss of muscle co-ordination and jerky movements due to acetylcholine buildup in muscles.
Animal studies also indicate that high doses of icariin, a compound found in horny goat weed, may be toxic to the kidneys and liver.
No drug interactions have been reported.
Chen KK and Chiu JH. Effect of Epimedium brevicornum Maxim extract on elicitation of penile erection in the rat. Urology. 67.3 (2006):631-5.
Oh MH et al. Screening of Korean herbal medicines used to improve cognitive function for anti-cholinesterase activity. Phytomedicine. 11.6 (2004):544-8.
Zhang CZ et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. Journal of Ethnopharmacology. 98.3 (2005):295-300.