Methyltestosterone

What it is and how it works

Mechanism class: Androgen Receptor Agonists

Indications

INDICATIONS AND USAGE 1. Males Androgens are indicated for replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone: Primary hypogonadism (congenital or acquired) — testicular failure due to cryptorchidism, bilateral torsions, orchitis, vanishing testis syndrome; or orchidectomy. Hypogonadotropic hypogonadism (congenital or acquired) — gonadotropin or luteinizing hormone-releasing hormone (LHRH) deficiency, or pituitary hypothalamic injury from tumors, trauma, or radiation. (Appropriate adrenal cortical and thyroid hormone replacement therapy are still necessary, however, and are actually of primary importance.) If the above conditions occur prior to puberty, androgen replacement therapy will be needed during the adolescent years for development of secondary sexual characteristics. Prolonged androgen treatment will be required to maintain sexual characteristics in these and other males who develop testosterone deficiency after puberty.

Dosage and administration (summary)

DOSAGE AND ADMINISTRATION Prior to initiating methyltestosterone, confirm the diagnosis of hypogonadism by ensuring that serum testosterone concentrations have been measured in the morning on at least two separate days and that these serum testosterone concentrations are below the normal range. Methyltestosterone capsules are administered orally. The suggested dosage for androgens varies depending on the age, sex, and diagnosis of the individual patient. Dosage is adjusted according to the patient’s response and the appearance of adverse reactions. Replacement therapy in androgen-deficient males is 10 mg to 50 mg of methyltestosterone daily.

Contraindications

CONTRAINDICATIONS Androgens are contraindicated in men with carcinomas of the breast or with known or suspected carcinomas of the prostate, and in women who are or may become pregnant. When administered to pregnant women, androgens cause virilization of the external genitalia of the female fetus. This virilization includes clitoromegaly, abnormal vaginal development, and fusion of genital folds to form a scrotal-like structure.

Warnings and precautions

WARNINGS In patients with breast cancer, androgen therapy may cause hypercalcemia by stimulating osteolysis. In this case, the drug should be discontinued. Prolonged use of high doses of androgens has been associated with the development of peliosis hepatis and hepatic neoplasms including hepatocellular carcinoma (see PRECAUTIONS — Carcinogenesis ). Peliosis hepatis can be a life-threatening or fatal complication. Cholestatic hepatitis and jaundice occur with 17-alpha-alkylandrogens at a relatively low dose.

Pregnancy

Pregnancy Teratogenic effects Pregnancy Category X (See CONTRAINDICATIONS ).

Storage and supply

HOW SUPPLIED Methyltestosterone Capsules USP, 10 mg are capsules with red translucent body and cap imprinted with “AA1” in black ink; containing white to off-white powder. They are available as follows: Bottles of 30: NDC 0115-1408-08 Bottles of 100: NDC 0115-1408-01 Bottles of 1000: NDC 0115-1408-03 Store at 20° to 25°C (68° to 77°F) .

Source: Methyltestosterone (Methyltestosterone) — US FDA prescribing information, 2025-05-31, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.