The primary use of<unk> is the treatment of males with too little or no natural<unk> production, also termed hypogonadism or hypoandrogenism (androgen deficiency). This treatment is referred to as hormone replacement therapy (HRT), or alternatively, and more specifically, as<unk> replacement therapy (TRT) or androgen replacement therapy (ART). It is used to maintain serum<unk> levels in the normal male range. Decline of<unk> production with age has led to interest in<unk> supplementation. A 2020 guidelines from the American College of Physicians support the discussion of<unk> in adult men with age-related low levels of<unk> who have sexual dysfunction. They recommend yearly evaluation regarding possible improvement and, if none, to discontinue<unk>  physicians should consider intramuscular treatments, rather than transdermal treatments, due to costs and since the effectiveness and harm of either method is similar.<unk> treatment for reasons other than possible improvement of sexual dysfunction may not be recommended. Deficiency<unk> deficiency (also termed hypotestosteronism or hypotestosteronemia) is an abnormally low<unk> production. It may occur because of testicular dysfunction (primary hypogonadism) or hypothalamic–pituitary dysfunction (secondary hypogonadism) and may be congenital or acquired. Low levels due to aging<unk> levels may decline gradually with age. The United States Food and Drug Administration (FDA) stated in 2015 that neither the benefits nor the safety of<unk> supplement have been established for low<unk> levels due to aging. The FDA has required that labels on<unk> include warnings about increased risk of heart attacks and stroke. Transgender men To take advantage of its virilizing effects,<unk> 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<unk> level. Women<unk> 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<unk> 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<unk> 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<unk> 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<unk> relative to those who had normal menopause. In addition to beneficial effects on sexual function,<unk> 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<unk> undecanoate than with parenteral routes, such as transdermal<unk> <unk> 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<unk> therapy was effective in improving multiple domains of sexual function. Androgenic adverse effects such as acne and hirsutism were significantly greater in incidence with<unk> 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<unk> 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<unk> is a critical hormone for sexual desire and function in women under normal physiological circumstances. Low doses of<unk> resulting in physiological levels of<unk> (50 ng/dL) significantly increase sexual desire in women, with levels of<unk> of 80 to 150 ng/dL "slightly" increasing sex drive. In accordance, men experience sexual dysfunction at<unk> levels of below 300 ng/dL, and men that have levels of<unk> of approximately 200 ng/dL frequently experience such problems. The high doses of<unk> 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<unk> therapy, its use may be inappropriate. In 2003, the FDA rejected Intrinsa, a 300 µg/day<unk> patch for the treatment of sexual dysfunction in postmenopausal women. The reasons cited were limited efficacy (about one additional sexually satisfying event per month), 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<unk>  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<unk> products approved for use in women in the United States and many other countries. There are approved<unk> products for women in Australia and some European countries.<unk> pellet implants are approved for use in postmenopausal women in the United Kingdom.<unk> products for men can be used off-label in women in the United States. Alternatively,<unk> products for women are available from compounding pharmacies in the United States, although such products are unregulated and manufacturing quality is not ensured. Available forms<unk> has been marketed for use by oral, sublingual, buccal, intranasal, transdermal (patches), topical (gels), intramuscular (injection), and subcutaneous (implant administration. It is provided unmodified and as a<unk> ester such as<unk> cypionate,<unk> enanthate,<unk> propionate, or<unk> undecanoate, which act as prodrugs of<unk>  The most common route of administration for<unk> is by intramuscular injection. However, it has been reported that AndroGel, a transdermal gel formulation of<unk>  has become the most popular form of<unk> in androgen replacement therapy for hypogonadism in the United States.
Testosterone 
Counterregulatory hormone
Menotropin
Luteinizing hormone
Orexin
Adrenocortical hormone
Androgen
Adrenalone