Evidence Level
Pycnogenol has one of the strongest evidence bases in the supplement industry, with over 160 published clinical studies. For men's health, the landmark study by Stanislavov & Nikolova (2003) showed that the combination of Pycnogenol 120mg + L-arginine 3g daily (marketed as Prelox) restored normal erectile function in 92.5% of men with organic erectile dysfunction after 3 months. The mechanism involves Pycnogenol's ability to stimulate eNOS and increase nitric oxide production, which is synergistically enhanced by L-arginine (the substrate for NO synthesis). Subsequent studies by Stanislavov et al. (2008, 2014) confirmed these findings in larger populations. Beyond sexual health, Pycnogenol has strong evidence for cardiovascular protection, with Enseleit et al. (2012) publishing a double-blind RCT showing improved endothelial function in coronary artery disease patients. Liu et al. (2004) demonstrated glycemic benefits as an adjunct to diabetes medication.