Topical testosterone supplementation for the treatment of male hypogonadism

Age-related hormonal decline is gradual and less recognized in men than in women. Symptoms are oftentimes ignored and non-specific. Fatigue, lack of concentration, mood swings, decreased sexual desire, erectile dysfunction, infertility, hair loss, reduced muscle and bone mass, and weight gain are a few of the symptoms of male hypogonadism. This disorder is linked to reduction in quality of life, and poorer health outcomes as it may increase the risk for cardiovascular disease, diabetes mellitus, metabolic syndrome, Alzheimer's disease and premature death. Different modalities of testosterone replacement therapy have evolved over 70 years, and sales continue to grow. Each preparation is differentiated by route of delivery, ease of use, cost and pharmacokinetics. Topical/transdermal testosterone replacement therapy, including patches and gels, are the most modern formulations on the market. These are more expensive treatments, but yield more physiological concentrations of testosterone. Restoration of testosterone levels to the eugonadal range reverses signs and symptoms of hypogonadism, except for infertility, and may alleviate co-morbidities associated with hypogonadism. Patient understanding of and compliance with both treatment and monitoring are of utmost importance to achieve clinical success with maximum benefit and minimum risk. The aim of our review is to summarize the indications, contraindications, benefits and risks of testosterone replacement therapy as they relate to transdermal administration. Further, we compare the various testosterone preparations, focusing on the newest topical/transdermal routes of administration that are currently available.