INN monograph
Testosterone
Androgen [EPC] · POM
Source-linked · Updated 03 Aug 2026 · Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Professional class pharmacology (Therapeutic agent (verify pharmacological class))
Kenya market
Wholesale / list prices where loaded
Risk first
Contraindications
- CONTRAINDICATIONS Androgens are contraindicated in men with carcinomas of the breast or with known or suspected carcinomas of the prostate.
- If administered to pregnant women, androgens cause virilization of the external genitalia of the female fetus.
- The virilization includes clitoromegaly, abnormal vaginal development, and fusion of genital folds to form a scrotal-like structure.
- The degree of masculinization is related to the amount of drug given and the age of the fetus, and is most likely to occur in the female fetus when the drugs are given in the first trimester.
- If the patient becomes pregnant while taking these drugs she should be apprised of the potential hazard to the fetus.
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, Mutagenesis, Impairment of Fertility).
- Peliosis hepatis can be a life-threatening or fatal complication.
- Men treated with androgens may be at an increased risk for the development of prostatic hypertrophy and prostatic carcinoma.
- There have been postmarketing reports of venous thromboembolic events, including deep vein thrombosis (DVT) and pulmonary embolism (PE), in patients using testosterone products, such as TESTOPEL ® (testosterone pellets).
- Evaluate patients who report symptoms of pain, edema, warmth and erythema in the lower extremity for DVT and those who present with acute shortness of breath for PE.
- If a venous thromboembolic event is suspected, discontinue treatment with TESTOPEL ® (testosterone pellets) and initiate appropriate workup and management (see ADVERSE REACTIONS ).
- Long term clinical safety trials have not been conducted to assess the cardiovascular outcomes of testosterone replacement therapy in men.
- To date, epidemiologic studies and randomized controlled trials have been inconclusive for determining the risk of major adverse cardiovascular events (MACE), such as non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death, with the use of testosterone compared to non-use.
- Some studies, but not all, have reported an increased risk of MACE in association with use of testosterone replacement therapy in men.
- Patients should be informed of this possible risk when deciding whether to use or to continue to use TESTOPEL ® (testosterone pellets).
Point of care
Dosing
Adult
DOSAGE AND ADMINISTRATION Prior to initiating, TESTOPEL ® (testosterone pellets) 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. The suggested dosage for androgens varies depending on the age, and diagnosis of the individual patient. Dosage is adjusted according to the patient’s response and the appearance of adverse reactions. The dosage guideline for the testosterone pellets for replacement therapy in androgen-deficient males is 150mg to 450mg subcutaneously every 3 to 6 months. Various dosage regimens have been used to induce pubertal changes in hypogonadal males; some experts have advocated lower doses initially, gradually increasing the dose as puberty progresses, with or without a decrease in maintenance levels. Other experts emphasize that higher dosages are needed to induce pubertal changes and lower dosages can be used for maintenance after puberty. The chronological and skeletal ages must be taken into consideration, both in determining the initial dose and in adjusting the dose. Dosages in delayed puberty generally are in the lower range of that listed above and, for a limited duration, for example 4 to 6 months. The number of pellets to be implanted depends upon the minimal daily requirements of testosterone propionate determined by a gradual reduction of the amount administered parenterally. The usual dosage is as follows: implant two 75mg pellets for each 25mg testosterone propionate required weekly. Thus when a patient requires injections of 75mg per week, it is usually necessary to implant 450mg (6 pellets). With injections of 50mg per week, implantation of 300mg (4 pellets) may suffice for approximately three months. With lower requirements by injection, correspondingly lower amounts may be implanted. It has been found that approximately one-third of the material is absorbed in the first month, one-fourth in the second month and one-sixth in the third month. Adequate effect of the pellets ordinarily continues for three to four months, sometimes as long as six months.
Paediatric
See label paediatric section if present; otherwise use paediatric formulary — do not extrapolate adult doses.
Renal
Review renal impairment dosing; many agents need CrCl/eGFR adjustment.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Hepatic
Review hepatic impairment dosing; monitor LFTs if agent is hepatically cleared or hepatotoxic.
Safety
Drug interactions
- Professional use: confirm indication, dose, duration, monitoring and patient counselling points against current Kenya STG / EML and the product SmPC.
- Document allergy status and key interactions.
Safety
Adverse effects
- ADVERSE REACTIONS The following adverse reactions have been identified during post-approval use of testosterone replacement therapy, including TESTOPEL ® .
- Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
- Implantation Site Infection and Pellet Extrusion: (see WARNINGS) Endocrine and Urogenital, Male.
- Gynecomastia and excessive frequency and duration of penile erections.
- Oligospermia may occur at high dosages (see CLINICAL PHARMACOLOGY ).
- Skin and Appendages.
- Hirsutism, male pattern of baldness, and acne.
- Cardiovascular Disorders.
- Myocardial infarction, stroke.
- Fluid and Electrolyte Disturbances.
- Retention of sodium, chloride, water, potassium, calcium and inorganic phosphates.
- Gastrointestinal.
- Nausea, cholestatic jaundice, alterations in liver function tests, rarely hepatocellular neoplasms and peliosis hepatis (see WARNINGS ).
- Hematologic.
Use
Indications
- INDICATIONS AND USAGE MALES Androgens are indicated for replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone. a.
- Primary hypogonadism (congenital or acquired) - testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testes syndrome
- or orchiectomy. b.
- Hypogonadotropic hypogonadism (congenital or acquired) - gonadotropic LHRH deficiency, or pituitary - hypothalamic injury from tumors, trauma or radiation.
- If the above conditions occur prior to puberty, androgen replacement therapy will be needed during the adolescent years for development of secondary sex characteristics.
- Prolonged androgen treatment will be required to maintain sexual characteristics in these and other males who develop testosterone deficiency after puberty.
- Safety and efficacy of TESTOPEL ® (testosterone pellets) in men with “age-related hypogonadism” (also referred to as “late-onset hypogonadism”) have not been established. c.
- Androgens may be used to stimulate puberty in carefully selected males with clearly delayed puberty.
- These patients usually have a familial pattern of delayed puberty that is not secondary to a pathological disorder
- puberty is expected to occur spontaneously at a relatively late date.
- Brief treatment with conservative doses may occasionally be justified in these patients if they do not respond to psychological support.
- The potential adverse effect on bone maturation should be discussed with the patient and parents prior to androgen administration.
Pharmacology
Mode of action
Testosterone replacement therapy Mechanism is agent-specific.
Full mechanism text
Testosterone replacement therapy Mechanism is agent-specific. At receptor, enzyme, ion channel, transporter or microbial target level, the drug alters a physiological or pathological pathway to produce its therapeutic effect. Confirm precise molecular mechanism in current SmPC / pharmacology reference for this INN before high-stakes decisions.
ADME
Pharmacokinetics & PD
| Onset | Product-specific |
|---|---|
| Duration | Product-specific |
| Route | SUBCUTANEOUS |
| Distribution | such as beard, pubic, chest and axillary hair, laryngeal enlargements, vocal cord thickening, alterations in body musculature and fat distribution. Drugs in this class can also cause retention of nitrogen, sodium, potassium, phosphorus, and decreased urinary |
| Elimination | of calcium. Androgens have been reported to increase protein anabolism and decrease protein catabolism. Nitrogen balance is improved only when there is sufficient intake of calories and protein. Androgens are responsible for the growth spurt of adolescence and for the eventual te... |
| Half-life | as reported in the literature, ranging from 10-100 minutes. In many tissues the activity of testosterone appears to depend on reduction to dihydrotestosterone, which binds to cytosol receptor proteins. The steroid-receptor complex is transported to the nucleus where it initiates... |
Full PK/PD text
CLINICAL PHARMACOLOGY Endogenous androgens are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include the growth and maturation of prostate, seminal vesicles, penis and scrotum; the development of male hair distribution such as beard, pubic, chest and axillary hair, laryngeal enlargements, vocal cord thickening, alterations in body musculature and fat distribution. Drugs in this class can also cause retention of nitrogen, sodium, potassium, phosphorus, and decreased urinary excretion of calcium. Androgens have been reported to increase protein anabolism and decrease protein catabolism. Nitrogen balance is improved only when there is sufficient intake of calories and protein. Androgens are responsible for the growth spurt of adolescence and for the eventual termination of linear growth which is brought about by the fusion of the epiphyseal growth centers. In children, exogenous androgens accelerate linear growth rates, but may cause a disproportionate advancement in bone maturation. Use over long periods may result in fusion of the epiphyseal growth centers and termination of growth process. Androgens have been reported to stimulate the production of red blood cells by enhancing the production of erythropoietic stimulating factor. During exogenous administration of androgens, endogenous testosterone release is inhibited through feedback inhibition of pituitary luteinizing hormone (LH). At large doses of exogenous androgens, spermatogenesis may also be suppressed through feedback inhibition of pituitary follicle stimulating hormone (FSH). There is a lack of substantial evidence that androgens are effective in fractures, surgery, convalescence, and functional uterine bleeding. PHARMACOKINETICS Testosterone in plasma is 98 percent bound to a specific testosterone-estradiol binding globulin, and about 2 percent is free. Generally, the amount of this sex-hormone binding globulin in the plasma will determine the distribution of testosterone between the free and bound forms, and the free testosterone concentration will determine its half-life. About 90 percent of a dose of testosterone is excreted as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6 percent of a dose is excreted in feces, mostly in the unconjugated form. Inactivation of testosterone occurs primarily in the liver. Testosterone is metabolized to various 17-keto steroids through two different pathways. There are considerable variations of the half-life as reported in the literature, ranging from 10-100 minutes. In many tissues the activity of testosterone appears to depend on reduction to dihydrotestosterone, which binds to cytosol receptor proteins. The steroid-receptor complex is transported to the nucleus where it initiates transcription events and cellular changes related to androgen action.
Kenya
Brands & prices
| Brand | Company | Pack | KES |
|---|---|---|---|
| No brands linked yet. | |||
Special populations
Pregnancy & lactation
Pregnancy
Use only if potential benefit justifies potential risk; prefer agents with better reproductive data when alternatives exist.
Lactation
Assess infant risk vs benefit of maternal therapy; prefer agents with lactation data.
Diet
Food & alcohol
- Food
- Food
Trust
Sources & disclaimer
Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Professional class pharmacology (Therapeutic agent (verify pharmacological class))
Clinical review date not recorded.
Decision support only — not a substitute for clinical judgment, product SmPC, or Kenya STG/EML.