[11] Testosterone can be administered through several different routes, including topical gels or patches, nasal sprays, subdermal implants, or tablets dissolved inside the mouth.

[11] The FDA has required that labels on testosterone include warnings about increased risk of heart attacks and stroke.

[37] 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.

[38] Conversely, it was associated with a significant incidence of androgenic side effects, including acne and hirsutism (excessive facial/body hair growth).

[38] 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.

[38] 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.

[40][41] 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.

[40] 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.

[41] The high doses of testosterone required to increase sexual desire in women may have a significant risk of masculinization with long-term therapy.

[44] 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, [45] and some European countries.

[48] Testosterone has been marketed for use by oral, sublingual, buccal, intranasal, transdermal (patches), topical (gels), intramuscular (injection), and subcutaneous (implant) administration.

[65] Testosterone is classified as an anabolic agent and is on the World Anti-Doping Agency (WADA) List of Prohibited Substances and Methods.

[citation needed] Anabolic–androgenic steroids (AAS), including testosterone and its esters, have also been taken to enhance muscle development, strength, or endurance.

[citation needed] After a series of scandals and publicity in the 1980s (such as Ben Johnson's improved performance at the 1988 Summer Olympics), prohibitions of AAS use were renewed or strengthened by many sports organizations.

[67] This has proven contentious, with the Court of Arbitration for Sport suspending the IAAF policy due to insufficient evidence of a link between high androgen levels and improved athletic performance.

[78][79][80][81] Other side effects include increased hematocrit, which can require venipuncture in order to treat, and exacerbation of sleep apnea.

[11] The FDA has required that testosterone pharmaceutical labels include warning information about the possibility of an increased risk of heart attacks and stroke.

Symptoms of POME include cough, shortness of breath, tightening of the throat, chest pain, sweating, dizziness, and fainting.

[89] On January 31, 2014, reports of strokes, heart attacks, and deaths in men taking FDA-approved testosterone-replacement led the FDA to announce that it would be investigating the issue.

[90] Later, in September 2014, the FDA announced, as a result of the "potential for adverse cardiovascular outcomes", a review of the appropriateness and safety of Testosterone Replacement Therapy (TRT).

[91][92][93] The FDA now requires warnings in the drug labeling of all approved testosterone products regarding deep vein thrombosis and pulmonary embolism.

[106][107] In addition, local levels of DHT in so-called androgenic (5α-reductase-expressing) tissues are also markedly reduced,[106][107] and this can have a strong impact on certain effects of testosterone.

[108][109] On the other hand, 5α-reductase inhibitors may prevent or reduce adverse androgenic side effects of testosterone like scalp hair loss, oily skin, acne, and seborrhea.

[citation needed] Antiandrogens like cyproterone acetate, spironolactone, and bicalutamide can block the androgenic and anabolic effects of testosterone.

In contrast to the case of testosterone, such potentiation occurs to a reduced extent or not at all with most synthetic AAS (as well as with DHT), and this is primarily responsible for the dissociation of anabolic and androgenic effects with these agents.

[51][49][129] Methyltestosterone, one of the first synthetic AAS and orally active androgens, was introduced in 1935, but was associated with hepatotoxicity and eventually became largely medically obsolete.

[124][139][140] It is also referred to in Latin as testosteronum, in Spanish and Portuguese as testosterona, and in German, Dutch, and Russian and other Slavic languages as testosteron.

[139] Major brand names of testosterone and/or its esters include Andriol, Androderm, AndroGel, Axiron, Delatestryl, Depo-Testosterone, Intrinsa, Nebido, Omnadren, Primoteston, Sustanon, Testim, TestoGel, TestoPatch, Testoviron, and Tostran.

[149] Testosterone replacement can significantly improve exercise capacity, muscle strength and reduce QT intervals in men with chronic heart failure (CHF).

Over the 3 to 6-month course of the studies reviewed, testosterone therapy appeared safe and generally effective, and (ruling out prostate cancer) the authors found no justification to absolutely restrict its use in men with CHF.