Testosterone (medication)
Testosterone 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 administered through several different routes, including topical gels or patches, nasal sprays, subdermal implants, or tablets dissolved inside the mouth. Testosterone therapy has been associated with improvements in depressive symptoms, increased exercise capacity and muscle strength in men with chronic heart failure, and male contraception effectiveness.
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 should 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 Organization's List of Essential Medicines. It is available as a generic medication. In 2023, it was the 119th most commonly prescribed medication in the United States, with more than 5million prescriptions.
Medical uses
The primary use of testosterone is the treatment of males with too little or no natural testosterone production, also termed male hypogonadism or hypoandrogenism. This treatment is referred to as hormone replacement therapy, or alternatively, and more specifically, as testosterone replacement therapy or androgen replacement therapy. It is used to maintain serum testosterone levels in the normal male range. Decline of testosterone production with age has led to interest in testosterone supplementation.A 2020 guideline from the American College of Physicians supports the discussion of testosterone in adult men with age-related low levels of testosterone who have sexual dysfunction. They recommend yearly evaluation regarding possible improvement and, if none, to discontinue testosterone; physicians should consider intramuscular treatments, rather than transdermal treatments, due to costs and since the effectiveness and harm of either method is similar. Testosterone treatment for reasons other than possible improvement of sexual dysfunction may not be recommended.
Deficiency
Testosterone deficiency is an abnormally low testosterone production. It may occur because of testicular dysfunction or hypothalamic–pituitary dysfunction and may be congenital or acquired.Low levels due to aging
Testosterone levels may decline gradually with age. The United States Food and Drug Administration stated in 2015 that neither the benefits nor the safety of testosterone supplement have been established for low testosterone levels due to aging. The FDA has required that labels on testosterone include warnings about increased risk of heart attacks and stroke.Transgender men
To take advantage of its virilizing effects, testosterone, often shortened to T, 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 male's testosterone level.Women
Testosterone therapy is effective in the short-term for the treatment of hypoactive sexual desire disorder 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 cholesterol, and increased levels of low-density lipoprotein 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, 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. 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. Androgenic adverse effects such as acne and hirsutism were significantly greater in incidence with testosterone therapy, whereas no significant differences in "increase in facial hair, alopecia, voice deepening, urinary symptoms, breast pain, headache, site reaction to the patch, total adverse events, serious adverse events, reasons for withdrawal from the study, and the number of women who completed the study" were seen relative to controls.
Although testosterone has been found to be effective at improving sexual function in postmenopausal women, the doses employed have been supraphysiological. In contrast to these high doses, there is little support for the notion that testosterone is a critical hormone for sexual desire and function in women under normal physiological circumstances. Low doses of testosterone resulting in physiological levels of testosterone have not been found to significantly increase sexual desire or function in women in most studies. Similarly, there appears to be little or no relationship between total or free testosterone levels in the normal physiological range and sexual desire in premenopausal women. Only high doses of testosterone resulting in supraphysiological levels of testosterone significantly increase sexual desire in women, with levels of testosterone of 80 to 150 ng/dL "slightly" increasing sex drive. In accordance, men experience sexual dysfunction at testosterone levels of below 300 ng/dL, and men that have levels of testosterone of approximately 200 ng/dL frequently experience such problems. The high doses of testosterone required to increase sexual desire in women may have a significant risk of masculinization with long-term therapy. For this reason, and due to the unknown health effects and safety of testosterone therapy, its use may be inappropriate. In 2003, the FDA rejected Intrinsa, a 300 μg/day testosterone patch for the treatment of sexual dysfunction in postmenopausal women. The reasons cited were limited efficacy, concerns about safety and potential adverse effects with long-term therapy, and concerns about inappropriate off-label use. It appears that in women, rather than testosterone, estradiol may be the most important hormone involved in sexual desire, although data on the clinical use of estradiol to increase sexual desire in women is limited.
There are no testosterone products approved for use in women in the United States and many other countries. There are approved testosterone products for women in Australia, where it is considered a drug of dependence, medicines that are subject to misuse and trafficking, and some European countries. Testosterone pellet implants are approved for use in postmenopausal women in the United Kingdom. Testosterone products for men can be used off-label in women in the United States. Alternatively, testosterone products for women are available from compounding pharmacies in the United States, although such products are unregulated and manufacturing quality is not ensured.