Horny goat weed is an all-natural supplement that's been employed for centuries to treat many different issues. The active ingredient in horny goat ashwagandha Australia weed is icariin, which really is a form of flavonoid. Icariin has been shown to possess a number of benefits, including improved circulation, increased libido, and relief from anxiety and stress. Horny goat weed is also sometimes used as a natural treatment for sexual dysfunction and other man health issues. But what does the research actually say? Is horny goat weed effective? A number of studies have already been conducted on icariin, the active ingredient in horny.