What is Icariin?

Icariin is a natural flavonoid glycoside extracted from the Chinese medicinal plant Epimedium. It has a variety of pharmacological effects, including anti-osteoporosis, cardiovascular protection, anti-inflammation, anti-tumour, immunoprotection and improvement of sexual dysfunction, and is a potentially active ingredient in the treatment of a wide range of diseases. It is often paired with other drugs in Chinese medicine treatment for diseases such as kidney deficiency and rheumatism.

Icariin and erectile dysfunction

Animal studies have shown that Icariin has testosterone-mimetic properties and that 4 weeks of oral treatment may improve erectile function, an effect that is associated with increased PSM and expression of certain NOS in the CC of castrated rats. It has a similar mechanism of action to sildenafil citrate in that they both inhibit phosphodiesterase 5 (PDE5), an enzyme that "shuts down" erections. However, Icariin is milder and less potent than sildenafil and is available over-the-counter.

Icariin, as an herbal supplement, has been shown to inhibit PDE5, which fills the penis with blood in order to create an erection. Another study found that Icariin appeared to benefit rats with vascular damage, enabling them to synthesise nitric oxide in penile tissue better than a placebo. But there haven't been any human trials on Icariin and erectile dysfunction.

References:

[1] INDRATMOKO S, NURANI L H, WAHYUNINGSIH I, et al. Icariin Research Trends: Bibliometric Analysis[J]. Jurnal Penelitian Pendidikan IPA, 2023. DOI:10.29303/jppipa.v9i11.4717.

[2] WU-JIANG LIU. Effects of icariin on erectile function and expression of nitric oxide synthase isoforms in castrated rats[J]. Asian Journal of Andrology, 2005, 7 4: 381-388. DOI:10.1111/j.1745-7262.2005.00066.x.