Epimedium (horney goat weed)

Epimedium, also known as Barrenwort, Bishop's Hat, Fairy Wings, Horny Goatweed, or Yin Yang Huo. In traditional medicine epimedium has been used as an aphrodisiac. The active ingredient in epimedium is icariin. Like Viagra, icariin inhibits the activity of PDE-5. This can increase levels of nitric oxide in some tissues and can cause the relaxation of smooth muscle.