Epimedium extract (Horny Goat Weed) (11), (Figure 9): the Chinese refer to this herb as ‘yin yang huo’, which has been loosely translated as ‘licentious goat plant’; hence, its common name is well known as ‘horny goat weed’ by many Western cultures. Scientifically, studies have shown that Epimedium may restore low levels of both testosterone and thyroid hormone, bringing low levels back to their normal levels (5), which may account for some of its benefits in improving sexual libido. Other benefits to Epimedium involve increased muscle mass. Used for fatigue and aging, And vasodilatation effect; thus, most frequently used in treatment of sexual dysfunction in Traditional Chinese Medicine (12). The active substance from horny goat weed was reported by Xin Zhong Cheng at Beijing Medical University as Icarin—acts by increasing sexual activities and ICP levels in castrated rats after long term oral administration. It has no effects on serum testosterone level in castrated rats after long term oral administration. Instead Icariin increases nNOS and iNOS mRNA and protein expression in the corpus cavernosum after long term oral administration and hence may have long term efficacy on erectile dysfunction after oral administration.
Erectile dysfunction supplements and other natural remedies have long been used in Chinese, African and other cultures. But unlike prescription medications for erectile dysfunction, such as sildenafil (Viagra), vardenafil (Levitra, Staxyn), tadalafil (Cialis, Adcirca) and avanafil (Stendra), erectile dysfunction herbs and supplements haven't been well-studied or tested. Some can cause side effects or interact with other medications. And the amount of the active ingredient can vary greatly from product to product.