Shindel, A. W., Xin, Z.-C., Lin, G., Fandel, T. M., Huang, Y.-C., Banie, L., … Lue, T. F. (2010, February 5). Erectogenic and neurotrophic effects of icariin, a purified extract of horny goat weed (Epimedium spp.) in vitro and in vivo. The Journal of Sexual Medicine, 7(4), 1518-1528. Retrieved from http://onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2009.01699.x/full
Erectile dysfunction (ED) is commonly called impotence. It’s a condition in which a man can’t achieve or maintain an erection during sexual performance. Symptoms may also include reduced sexual desire or libido. Your doctor is likely to diagnose you with ED if the condition lasts for more than a few weeks or months. ED affects as many as 30 million men in the United States.