Testosterone

Clinical data
Pronunciation	/tɛˈstɒstəroʊn/ teh-STOS-tə-rohn[1]
Trade names	AndroGel, Testim, TestoGel, others
Other names	Androst-4-en-17β-ol-3-one
AHFS/Drugs.com	Monograph
MedlinePlus	a619028
License data	US DailyMed: Testosterone
Pregnancy category	AU: D[2] Contraindicated due to teratogenic effects
Routes of administration	By mouth, buccal, sublingual, intranasal, transdermal (gel, cream, patch, solution), vaginal (cream, gel, suppository), rectal (suppository), intramuscular or subcutaneous injection (oil solution, aqueous suspension), subcutaneous implant (pellet)
Drug class	Androgen, anabolic steroid
ATC code	G03BA03 (WHO)
Legal status
Legal status	AU: [citation needed] BR: Class C5 (Anabolic steroids)[4] CA: Schedule IV[citation needed] DE: [citation needed] NZ: [citation needed] UK: Class C[citation needed] US: WARNING[3]Schedule III[citation needed] UN: [citation needed] EU: Rx-only[5][6] Rx-only[citation needed]
Pharmacokinetic data
Bioavailability	Oral: very low (due to extensive first pass metabolism)
Protein binding	97.0–99.5% (to SHBGTooltip sex hormone-binding globulin and albumin)[7]
Metabolism	Liver (mainly reduction and conjugation)
Elimination half-life	2–4 hours[citation needed]
Excretion	Urine (90%), feces (6%)
Identifiers
IUPAC name (8R,9S,10R,13S,14S,17S)-17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopentaphenanthren-3-one
CAS Number	58-22-0 Y 57-85-2 (propionate) 315-37-7 (enanthate) 58-20-8 (cypionate) 5949-44-0 (undecanoate)
PubChem CID	6013
IUPHAR/BPS	2858
DrugBank	DB00624 Y
ChemSpider	5791 Y
UNII	3XMK78S47O
KEGG	D00075 Y
ChEBI	CHEBI:17347 Y
ChEMBL	ChEMBL386630 Y
Chemical and physical data
Formula	C19H28O2
Molar mass	288.431 g·mol−1
3D model (JSmol)	Interactive image
Specific rotation	+110.2°
Melting point	155 °C (311 °F)
SMILES O=C4\C=C2/(1CC3((O)CC31CC2)C)(C)CC4
InChI InChI=1S/C19H28O2/c1-18-9-7-13(20)11-12(18)3-4-14-15-5-6-17(21)19(15,2)10-8-16(14)18/h11,14-17,21H,3-10H2,1-2H3/t14-,15-,16-,17-,18-,19-/m0/s1 Y Key:MUMGGOZAMZWBJJ-DYKIIFRCSA-N Y
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Testosterone (T) is a medication and naturally occurring steroid hormone.^[8] It is used to treat male hypogonadism, gender dysphoria, and certain types of breast cancer.^[8][9] It may also be used to increase athletic ability in the form of doping.^[8] It is unclear if the use of testosterone for low levels due to aging is beneficial or harmful.^[10] 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.^[8]

Common side effects of testosterone include acne, swelling, and breast enlargement in men.^[8] Serious side effects may include liver toxicity, heart disease, and behavioral changes.^[8] Women and children who are exposed may develop masculinization.^[8] It is recommended that individuals with prostate cancer should not use the medication.^[8] It can cause harm to the baby if used during pregnancy or breastfeeding.^[8] Testosterone is in the androgen family of medications.^[8]

Testosterone was first isolated in 1935, and approved for medical use in 1939.^[11][12] Rates of use have increased three times in the United States between 2001 and 2011.^[13] It is on the World Health Organization's List of Essential Medicines.^[14] It is available as a generic medication.^[8] In 2021, it was the 143rd most commonly prescribed medication in the United States, with more than 4 million prescriptions.^[15][16]

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 (androgen deficiency).^[17] This treatment is referred to as hormone replacement therapy (HRT), or alternatively, and more specifically, as testosterone replacement therapy (TRT) or androgen replacement therapy (ART). 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.^[18]

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.^[19][20]

Deficiency

Testosterone deficiency (also termed hypotestosteronism or hypotestosteronemia) is an abnormally low testosterone production. It may occur because of testicular dysfunction (primary hypogonadism) or hypothalamic–pituitary dysfunction (secondary hypogonadism) and may be congenital or acquired.^{[21][medical citation needed]}

Low levels due to aging

Testosterone levels may decline gradually with age.^[22][23] The United States Food and Drug Administration (FDA) stated in 2015 that neither the benefits nor the safety of testosterone supplement have been established for low testosterone levels due to aging.^[10] The FDA has required that labels on testosterone include warnings about increased risk of heart attacks and stroke.^[10]

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,^[24] titrated to clinical effect with a "target level" of the average male's testosterone level.^[25]