# Androgen replacement therapy

Androgen replacement therapy (ART), often referred to as testosterone replacement therapy (TRT), is a form of hormone therapy in which androgens, often testosterone, are supplemented or replaced. It typically involves the administration of testosterone through injections, skin creams, patches, gels, pills, or subcutaneous pellets. ART is often prescribed to counter the effects of male hypogonadism.
ART is also prescribed to lessen the effects or delay the onset of normal male aging. However, this is controversial and is the subject of ongoing clinical trials.
As men enter middle age they may notice changes caused by a relative decline in testosterone: fewer erections, fatigue, thinning skin, declining muscle mass and strength, and/or more body fat. Dissatisfaction with these changes causes some middle age men to seek ART. Androgen deficiencies in women have also, as of 2001, been recognized as a medical disorder that can be treated with ART. As with men, symptoms associated with androgen deficiency are most prevalent with age, and androgen replacement therapy has been shown to help with symptoms of menopause.

## Medical uses
### Males

Androgen replacement is the classic treatment of hypogonadism. It is also used in men who have lost the ability to produce androgens due to disease or its treatment.
vte Androgen replacement therapy formulations and dosages used in men :
| Route | Medication | Major brand names | Form | Dosage |
| Oral | Testosterone$^a$ | – | Tablet | 400–800 mg/day (in divided doses) |
| Oral | Testosterone undecanoate | Andriol, Jatenzo | Capsule | 40–80 mg/2–4× day (with meals) |
| Oral | Methyltestosterone$^b$ | Android, Metandren, Testred | Tablet | 10–50 mg/day |
| Oral | Fluoxymesterone$^b$ | Halotestin, Ora-Testryl, Ultandren | Tablet | 5–20 mg/day |
| Oral | Metandienone$^b$ | Dianabol | Tablet | 5–15 mg/day |
| Oral | Mesterolone$^b$ | Proviron | Tablet | 25–150 mg/day |
| Sublingual | Testosterone$^b$ | Testoral | Tablet | 5–10 mg 1–4×/day |
| Sublingual | Methyltestosterone$^b$ | Metandren, Oreton Methyl | Tablet | 10–30 mg/day |
| Buccal | Testosterone | Striant | Tablet | 30 mg 2×/day |
| Buccal | Methyltestosterone$^b$ | Metandren, Oreton Methyl | Tablet | 5–25 mg/day |
| Transdermal | Testosterone | AndroGel, Testim, TestoGel | Gel | 25–125 mg/day |
| Transdermal | Testosterone | Androderm, AndroPatch, TestoPatch | Non-scrotal patch | 2.5–15 mg/day |
| Transdermal | Testosterone | Testoderm | Scrotal patch | 4–6 mg/day |
| Transdermal | Testosterone | Axiron | Axillary solution | 30–120 mg/day |
| Transdermal | Androstanolone (DHT) | Andractim | Gel | 100–250 mg/day |
| Rectal | Testosterone | Rektandron, Testosteron$^b$ | Suppository | 40 mg 2–3×/day |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone | Andronaq, Sterotate, Virosterone | Aqueous suspension | 10–50 mg 2–3×/week |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone propionate$^b$ | Testoviron | Oil solution | 10–50 mg 2–3×/week |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone enanthate | Delatestryl | Oil solution | 50–250 mg 1x/1–4 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone enanthate | Xyosted | Auto-injector | 50–100 mg 1×/week |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone cypionate | Depo-Testosterone | Oil solution | 50–250 mg 1x/1–4 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone isobutyrate | Agovirin Depot | Aqueous suspension | 50–100 mg 1x/1–2 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone phenylacetate$^b$ | Perandren, Androject | Oil solution | 50–200 mg 1×/3–5 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Mixed testosterone esters | Sustanon 100, Sustanon 250 | Oil solution | 50–250 mg 1×/2–4 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone undecanoate | Aveed, Nebido | Oil solution | 750–1,000 mg 1×/10–14 weeks |
| Injection (IMTooltip intramuscular injection or SCTooltip subcutaneous injection) | Testosterone buciclate$^a$ | – | Aqueous suspension | 600–1,000 mg 1×/12–20 weeks |
| Implant | Testosterone | Testopel | Pellet | 150–1,200 mg/3–6 months |
| Notes: Men produce about 3 to 11 mg of testosterone per day (mean 7 mg/day in young men). Footnotes: $^a$ = Never marketed. $^b$ = No longer used and/or no longer marketed. Sources: See template. |||||

#### Diabetes

The risks of diabetes and of testosterone deficiency in men over 45 (i.e., hypogonadism, specifically hypoandrogenism) are strongly correlated. Testosterone replacement therapies have been shown to improve blood glucose management. Still, "it is prudent not to start testosterone therapy in men with diabetes solely for the purpose of improving metabolic control if they show no signs and symptoms of hypogonadism."

### Females

Androgen replacement is used in postmenopausal women: the indications are to increase sexual desire; and to prevent or treat osteoporosis. Other symptoms of androgen deficiency are similar in both sexes, such as muscle loss and physical fatigue. The androgens used for androgen replacement in women include testosterone (and esters), prasterone (dehydroepiandrosterone; DHEA) (and the ester prasterone enanthate), methyltestosterone, nandrolone decanoate, and tibolone, among others.
vte Androgen replacement therapy formulations and dosages used in women :
| Route | Medication | Major brand names | Form | Dosage |
| Oral | Testosterone undecanoate | Andriol, Jatenzo | Capsule | 40–80 mg 1x/1–2 days |
| Oral | Methyltestosterone | Metandren, Estratest | Tablet | 0.5–10 mg/day |
| Oral | Fluoxymesterone | Halotestin | Tablet | 1–2.5 mg 1x/1–2 days |
| Oral | Normethandrone$^a$ | Ginecoside | Tablet | 5 mg/day |
| Oral | Tibolone | Livial | Tablet | 1.25–2.5 mg/day |
| Oral | Prasterone (DHEA)$^b$ | – | Tablet | 10–100 mg/day |
| Sublingual | Methyltestosterone | Metandren | Tablet | 0.25 mg/day |
| Transdermal | Testosterone | Intrinsa | Patch | 150–300 μg/day |
| Transdermal | Testosterone | AndroGel | Gel, cream | 1–10 mg/day |
| Vaginal | Prasterone (DHEA) | Intrarosa | Insert | 6.5 mg/day |
| Injection | Testosterone propionate$^a$ | Testoviron | Oil solution | 25 mg 1x/1–2 weeks |
| Injection | Testosterone enanthate | Delatestryl, Primodian Depot | Oil solution | 25–100 mg 1x/4–6 weeks |
| Injection | Testosterone cypionate | Depo-Testosterone, Depo-Testadiol | Oil solution | 25–100 mg 1x/4–6 weeks |
| Injection | Testosterone isobutyrate$^a$ | Femandren M, Folivirin | Aqueous suspension | 25–50 mg 1x/4–6 weeks |
| Injection | Mixed testosterone esters | Climacteron$^a$ | Oil solution | 150 mg 1x/4–8 weeks |
| Injection | Mixed testosterone esters | Omnadren, Sustanon | Oil solution | 50–100 mg 1x/4–6 weeks |
| Injection | Nandrolone decanoate | Deca-Durabolin | Oil solution | 25–50 mg 1x/6–12 weeks |
| Injection | Prasterone enanthate$^a$ | Gynodian Depot | Oil solution | 200 mg 1x/4–6 weeks |
| Implant | Testosterone | Testopel | Pellet | 50–100 mg 1x/3–6 months |
| Notes: Premenopausal women produce about 230 ± 70 μg testosterone per day (6.4 ± 2.0 mg testosterone per 4 weeks), with a range of 130 to 330 μg per day (3.6–9.2 mg per 4 weeks). Footnotes: $^a$ = Mostly discontinued or unavailable. $^b$ = Over-the-counter. Sources: See template. |||||

## Adverse effects

The Food and Drug Administration (FDA) stated in 2015 that neither the benefits nor the safety of testosterone have been established for low testosterone levels due to aging. The FDA has required that testosterone labels include warning information about the possibility of an increased risk of heart attacks and stroke.

### Heart disease

On January 31, 2014, reports of strokes, heart attacks, and deaths in men taking testosterone-replacement led the FDA to announce that it would be investigating this issue. The FDA's action followed three peer-reviewed studies of increased cardiovascular events and deaths. Due to an increased rate of adverse cardiovascular events compared to a placebo group, a randomized trial stopped early. Also, in November 2013, a study reported an increase in deaths and heart attacks in older men. Concerns have been raised that testosterone was being widely marketed without the benefit of data on efficacy and safety from large randomized controlled trials. As a result of the "potential for adverse cardiovascular outcomes", the FDA announced, in September 2014, a review of the appropriateness and safety of testosterone replacement therapy. However, when given to men with hypogonadism in the short- and medium-term, testosterone replacement therapy does not increase the risk of cardiovascular events (including strokes and heart attacks and other heart diseases). The long-term safety of the therapy is not known yet.

### Other

Other significant adverse effects of testosterone supplementation include acceleration of pre-existing prostate cancer growth in individuals who have undergone androgen deprivation; increased hematocrit, which can require venipuncture in order to treat; and, exacerbation of sleep apnea. A 2014 review said there was some evidence men with certain comorbidities may be at risk of adverse effects including sleep apnoea, metabolic syndrome and cardiovascular disease. Exogenous testosterone may also cause suppression of spermatogenesis, leading to, in some cases, infertility. It is recommended that physicians screen for prostate cancer with a digital rectal exam and prostate-specific antigen (PSA) level before starting therapy, and monitor PSA and hematocrit levels closely during therapy.
Some studies argue that ART increases the risk of prostate cancer, although the results are not conclusive.

## Methods of administration

There are several artificial androgens, many of which are manipulations of the testosterone molecule referred to as anabolic-androgenic steroids. Androgen replacement is administered by patch, tablet, capsule, cream or gel; or depot injections given into fat or muscle.

## Society and culture
### MMA

Some UFC fighters used TRT until 2014 when the Nevada State Athletic Commission banned its use.

### Regulation

As of September 2014, testosterone replacement therapy has been under review for appropriateness and safety by the Food and Drug Administration due to the "potential for adverse cardiovascular outcomes".

### Frequency of use

In the United States usage increased from 0.5% in 2002 to 3.2% in 2013 and have since decreased to 1.7% in 2016.
A UK study in 2013 showed that prescriptions for testosterone replacement, particularly transdermal products, almost doubled between 2000 and 2010.

## Research

Testosterone is being investigated as therapy for the following conditions:
* Erectile dysfunction
* Osteoporosis
* Diabetes mellitus
* Chronic heart failure
* Dementia, but the evidence base is small and the balance of benefit needs to be clarified