Transgender men
To take advantage of its virilizing effects, testosterone is administered to transgender men and other transmasculine individuals as part of masculinizing hormone therapy, titrated to clinical effect with a "target level" of the average males testosterone level. Women
Testosterone therapy is effective in the short-term for the treatment of hypoactive sexual desire disorder (HSDD) in women. However, its long-term safety is unclear. Because of a lack data to support its efficacy and safety, the Endocrine Society recommends against the routine use of testosterone in women to treat low androgen levels due to hypopituitarism, adrenal insufficiency, surgical removal of the ovaries, high-dose corticosteroid therapy, or other causes. Similarly, because of a lack of data to support its efficacy and safety, the Endocrine Society recommends against the use of testosterone in women to improve general well-being, to treat infertility, sexual dysfunction due to causes other than HSDD, or to improve cognitive, cardiovascular, metabolic, and/or bone health.A 2014 systematic review and meta-analysis of 35 studies consisting of over 5,000 postmenopausal women with normal adrenal gland function found that testosterone therapy was associated with significant improvement in a variety of domains of sexual function. These domains included frequency of sexual activity, orgasm, arousal, and sexual satisfaction, among others. Women who were menopausal due to ovariectomy showed significantly greater improvement in sexual function with testosterone relative to those who had normal menopause. In addition to beneficial effects on sexual function, testosterone was associated with unfavorable changes in blood lipids.
These included decreased levels of total cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol, and increased levels of low-density lipoprotein (LDL) cholesterol. However, the changes were small in magnitude, and the long-term significance in relation to cardiovascular outcomes is uncertain. The changes were more pronounced with oral testosterone undecanoate than with parenteral routes, such as transdermal testosterone. Testosterone showed no significant effect on depressed mood anxiety, bone mineral density (BMD), or anthropomorphic measures like body weight or body mass index. Conversely, it was associated with a significant incidence of androgenic side effects, including acne and hirsutism (excessive facial/body hair growth). Other androgenic side effects, such as weight gain, pattern hair loss, and voice deepening, were also reported in some trials, but were excluded from analyses due to insufficient data. The overall quality of the evidence was rated as low and was considered to be inconclusive in certain areas, for instance on long-term safety.A subsequent 2017 systematic review and meta-analysis of studies including over 3,000 postmenopausal women with HSDD similarly found that short-term transdermal testosterone therapy was effective in improving multiple domains of sexual function.