With a name like horny goat weed (Epimedium), you would expect this supplement to benefit sexual health and help with erectile dysfunction, and indeed this herb has a millennia-old history of use as an aphrodisiac in Traditional Chinese Medicine. Although experts are not sure exactly how horny goat weed works, men say it can improve erectile function, and both men and women report that it enhances sexual desire.
Among the few studies of horny goat weed are three that suggest one of the flavonoids in the herb, icariin, may be the substance responsible for its help with erectile dysfunction. (Chen; Chiu; Shindel) Icariin appears to relax penile tissue by nitric oxide and by inhibiting PDE-5 activity, which is how Viagra and other erectile dysfunction drugs work.
Thus far, scientists have not conducted any long-term toxicity studies of icariin or horny goat weed in any animal models. In addition, no studies have identified a safe dose of horny goat weed, and no randomized clinical trials have been performed using this natural remedy.
References
Chen KK, Chiu JH. Effect of Epimedium brevicornum Maxim extract on elicitation of penile erection in the rat. Urology 2006; 67:631-35
Chiu JH et al. Epimedium brevicornum Maxim extract relaxes rabbit corpus cavernosum through multitargets on nitric oxide/cyclic guanosine monophosphate signaling pathway. Int J Impot Res 2006; 18:335-42
Corazza O et al. Sexual enhancement products for sale online: raising awareness of the psychoactive effects of yohimbine, maca, horny goat weed, and Ginkgo biloba. Biomed Res Int 2014; 2014:841798
Shindel AW, et al. Erectogenic and neurotrophic effects of icariin, a purified extract of horny goat weed (Epimedium spp) in vitro and in vivo. J Sex Med 2010 Feb 5
