So, why isn’t anyone discussing using Octyl Salicylate in their transdermal homebrews? Octyl Salicylate has been proven to be an effective penetration enhancer when used with Testosterone. In the attached study, OS was shown to increase the penetration of testosterone by a factor of six. That is a huge number. In addition, it is the first ingredient that Par discusses in his transdermal article. Granted, its not cheap. I paid $30 for 500 ml’s. Its not often that we have solid evidence (or studies) relating to the transdermal absorption of hormones with various penetration enhancers. We do have it with OS. The attached article from Science Magazine is very interesting.