Testosterone (T) is a medication and naturally occurring steroid hormone. It is used to treat male hypogonadism, gender dysphoria, and certain types of breast cancer. It may also be used to increase athletic ability in the form of doping. It is unclear if the use of testosterone for low levels due to aging is beneficial or harmful. Testosterone can be used as a gel or patch that is applied to the skin, injection into a muscle, tablet that is placed in the cheek, or tablet that is taken by mouth.Common side effects of testosterone include acne, swelling, and breast enlargement in men. Serious side effects may include liver toxicity, heart disease, and behavioral changes. Women and children who are exposed may develop masculinization. It is recommended that individuals with prostate cancer not use the medication. It can cause harm to the baby if used during pregnancy or breastfeeding. Testosterone is in the androgen family of medications.Testosterone was first isolated in 1935, and approved for medical use in 1939. Rates of use have increased three times in the United States between 2001 and 2011. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 126th most commonly prescribed medication in the United States, with more than 5 million prescriptions. Medical uses
The primary use of testosterone is the treatment of males with too little or no natural testosterone production, also termed hypogonadism or hypoandrogenism (androgen deficiency).
Relative contraindications of testosterone include elevated prostate-specific antigen (PSA) in men with a high risk of prostate cancer due to ethnicity or family history, severe lower urinary tract symptoms, and elevated hematocrit (>50%). Side effects
Adverse effects may also include minor side effects such as oily skin, acne, and seborrhea, as well as loss of scalp hair, which may be prevented or reduced with 5α-reductase inhibitors. In women, testosterone can produce hirsutism (excessive facial/body hair growth), deepening of the voice, and other signs of virilization. Exogenous testosterone may cause suppression of spermatogenesis in men, leading to, in some cases, reversible infertility. Gynecomastia and breast tenderness may occur with high dosages of testosterone due to peripheral conversion of testosterone by aromatase into excessive amounts of the estrogen estradiol. Testosterone treatment, particularly in high dosages, can also be associated with mood changes, increased aggression, increased sex drive, spontaneous erections, and nocturnal emissions.Other side effects include increased hematocrit, which can require venipuncture in order to treat, and exacerbation of sleep apnea.The FDA stated in 2015 that neither the benefits nor the safety of testosterone have been established for low testosterone levels due to aging. The FDA has required that testosterone pharmaceutical labels include warning information about the possibility of an increased risk of heart attacks and stroke. They have also required the label include concerns about abuse and dependence.Injectable forms of testosterone can cause a lung problem called pulmonary oil microembolism (POME). Symptoms of POME include cough, shortness of breath, tightening of the throat, chest pain, sweating, dizziness, and fainting.