Testosterone Reference

Plain English

What it is

Testosterone is the main male sex hormone. As a medicine it is FDA-approved and sold under brand names like Depo-Testosterone (an injection) and AndroGel (a skin gel) to replace testosterone in men whose bodies do not make enough, a confirmed condition doctors call low testosterone or hypogonadism. It is also a Schedule III controlled substance, which means the law limits how it can be prescribed and used.

What people use it for

Doctors prescribe it for men with confirmed low testosterone to restore normal levels and correct the symptoms of that deficiency. People in bodybuilding and lifting communities also use it off-label to build muscle, but that non-medical use is illegal and banned in competitive sport.

What the science shows

Using testosterone to treat confirmed low testosterone is supported by major medical guidelines, including the Endocrine Society clinical practice guideline. A large safety study the FDA required (called TRAVERSE) found that in men with low testosterone and heart risk, testosterone did not raise the overall rate of major heart events compared with a placebo. The testosterone group did, however, have more blood clots in the lungs, irregular heartbeat, and sudden kidney injury.

The catch

Testosterone is a controlled prescription medicine, not a fitness supplement, and its FDA label warns it can raise blood pressure and can be abused and cause serious harm when taken in high amounts. The gel forms can rub off onto women and children through skin contact and cause unwanted effects, and blood counts need regular checks because testosterone can thicken the blood. Using it without a prescription, including for bodybuilding, is illegal and banned in competitive sport.

Reference summary

Endocrine Society 2018 clinical practice guideline (Bhasin 2018 JCEM) is the bedrock prescribing reference: biochemical confirmation, target trough to mid-normal range, lab monitoring schedule (hematocrit, PSA, lipids), and contraindications (untreated obstructive sleep apnea, hematocrit >54 percent, breast or prostate cancer, recent MI, severe heart failure). TRAVERSE (Lincoff 2023 NEJM, n=5,246) was the FDA-mandated post-marketing cardiovascular safety trial; it reported non-inferiority of testosterone vs placebo for the primary MACE composite over a mean 21.7 months in men with hypogonadism and pre-existing or high cardiovascular risk, but did report higher rates of pulmonary embolism, atrial fibrillation, and acute kidney injury in the testosterone arm.

Regulatory and posture

Categories

Hormonal, Reproductive

Aliases

Testosterone cypionate (Depo-Testosterone), Testosterone enanthate (Xyosted), Testosterone propionate, Testosterone undecanoate (Aveed, Jatenzo), Schedule III controlled substance, Anabolic-androgenic steroid (small molecule, not a peptide)

Evidence posture

human - TRAVERSE showed cardiovascular non-inferiority but higher PE / AF / AKI in the testosterone arm. Erythrocytosis monitoring is mandatory.

Regulatory status

FDA-approved Schedule III controlled substance for testosterone replacement therapy (TRT) in men with primary or hypogonadotropic hypogonadism, with biochemical confirmation (typically two morning total testosterone measurements below the local lab reference range plus clinical signs). Multiple esters and routes are approved: cypionate and enanthate for IM injection, propionate (less commonly used today), undecanoate IM (Aveed) or oral (Jatenzo), transdermal gels (AndroGel, Testim), and patches. Compounded subcutaneous testosterone is an off-label preparation that some prescribers use; the dose is not FDA-validated at the protocol level. WADA-prohibited at all times under S1.

Content review status

label verified

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