You are probably wondering how a Botox treatment, which is to relax muscles, can aid erections. The answer is Botox that relaxes the smooth muscles that control blood flow through the arteries of the penis.  When the smooth muscle relaxes, the arteries increase in diameter, and more blood flows into the penis—causing improved erection and increased length.

This increase in erection firmness by increasing arterial flow is exactly how Viagra and Tri-mix injections work. In two separate studies, the injection of Botox was helpful to many men for whom Viagra and Cialis had quit working.