Testosterone may induce a noticeable increase in libido without exerting a positive effect on erectile capabilities in patients with ED who do not have an androgen insufficiency. Testosterone can be used to treat erectile dysfunction when the main cause is a decrease in the level of testosterone in the body, also known as hypogonadism or andropause. Testosterone works by increasing libido, and is also necessary to develop an erection.
Testosterone reverses the effects of apoptosis (cellular death) in the cavernosal smooth muscle cells. This allows hypogonadal men to improve their sexual function and increase response to ED treatments. According to a study done by Clinical Endocrinology, using testosterone in conjunction with PDE5 Inhibitors can improve the erectile response by increasing blood flow. Testosterone can be applied topically in a gel, via a patch, or by an intramuscular injection. Testosterone cannot be used by men with prostate cancer.