Types of testosterone replacement therapy include a transdermal skin patch, gels, a mouth patch, injections or implants. Oral testosterone may negatively affect the liver, so doctors prefer to use therapies that bypass the liver and go directly into the bloodstream, according to WebMD.
Androderm is a testosterone skin patch that the patient applies once a day onto the arm or upper body. Testosterone gels such as AndroGel, Testim, or Fortesta absorb through the skin, while Natesto absorbs through the nose. Striant is a mouth patch that sticks to the upper gums and continuously releases testosterone to the blood through twice daily applications. Testosterone is also available as an injection to the muscles or as an implant in the body's soft tissues, allowing the testosterone to slowly enter the bloodstream. All the forms of testosterone replacement work effectively in raising testosterone levels, states WebMD.
Men who undergo testosterone replacement therapy often experience improved energy, better moods, and increased sex drive and quality of erections, says WebMD. Other benefits of testosterone include increases in bone density, muscle mass and insulin sensitivity. The most common side effects are a rash, irritation or itchy skin at the site of the testosterone placement. There is also evidence that testosterone use increases the risk of heart attack or stroke.