Icariin increases male's virility

1)Icariin, extracted from a chinese traditional herb Yinyanghuo increases male's virility.
2)Studies had found that it relaxed corpus cavernosum and increase nitiric oxide level
3)Icariin is a specific inhibitor of phoshodiesterase , a molecule that degrades cGMP.--- A recent study
4) cGMP is found to mediate the release of nitric oxide.

Reference: ffn