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
Nitric oxide is made internally from L-arginine, which is an amino acid found in red meat, poultry, fish, and dairy products. In other words, L-arginine is the building block for nitric oxide, which is essential for erections. A lack of one can lead to a lack of the other. However, there’s a problem when it comes to treating L-arginine deficiency with supplements.
Tribulus terrestris is a dicotyledonous herbal plant of the Zygophyllaceae family, used to increase serum testosterone levels, which has only been shown in animal studies (40). A prospective, randomized, double blind study of 30 men showed that Tribulus terrestris was not more effective than placebo on improving IIEF scores or serum total testosterone (41). Two accounts of hepato-nephrotoxicity have been reported in young men who ingested high doses of this herbal medication (42,43).
In fact, one common reason many younger men visit their doctor is to get erectile dysfunction medication. Often, men with erectile dysfunction suffer with diabetes or heart disease, or may be sedentary or obese, but they don’t realize the impact of these health conditions on sexual function. Along with erectile dysfunction treatment, the doctor may recommend managing the illness, being more physically active, or losing weight.