Epimedium extract

Horny Goat Weed is a herb (Epimedium) that is known for being an aphrodisiac and touted as a Testosterone Booster. It derives its layman names from goats and sheep that acted a bit more frisky after consuming Epimedium that grew near their fields.
It is mainly in the Chinese tradition that we consider Epimedium as a medicinal plant. Chinese herbalists called epimedium Yin Yang Huo, which means “Main or first balance of Yin (female energy) and Yang (masculine energy).” Although most often Chinese herbalists use different species of Epimedium such as E. brevicornum, sagittatum E., E. acuminatum, koreanum E., E. pubescens, E. wushanense, etc. However, the genuine or original one was Epimedium grandiflora.

According to the principles of Chinese medicine, epimedium tones the kidneys and fortifies the yang.
As with many supplements, the claims about the effectiveness of horny goat weed are expansive. And, as is also true with many supplements, researches on the effects of horny goat weed on humans are definitely limited.

A study published in the Journal of Sexual Medicine investigated its effects on rats. Researchers found that rats treated with purified extract of horny goat weed showed improved erectile function. Another study found that icariin is effective in inhibiting human PDE5, the substance that blocks erections, in test tubes. But it also determined that sildenafil (Viagra) is 80 times more potent than icariin.