It doesn’t look good for the herbs. So far, there’s no data from controlled human trials that support the erection-promoting claims for any 5 of the most frequently used herbs. The icariin in the horny goat weed can help get it up, but since you’re getting the herb rather than a purified molecule, the concentration probably isn’t high enough to have much of an effect. Worse, it turns out that Viagra is much better at blocking that erection-killing enzyme than icariin is.
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.