Testosterone is a naturally occurring androgenic anabolic steroid hormone, primarily secreted by the Leydig cells of the testes. In its exogenous form, as a 250mg injectable preparation, it is a long-acting ester (typically testosterone enanthate or cypionate) used for testosterone replacement therapy (TRT) in males. It is a Schedule H drug in India, requiring strict medical supervision. It corrects the symptoms and signs of hypogonadism by restoring physiological testosterone levels.
Adult: For testosterone replacement in hypogonadism: 250mg intramuscularly every 2 to 4 weeks. Dose and interval MUST be individualized based on trough serum testosterone levels measured just before the next injection. Typical target range: 400-700 ng/dL.
Note: For deep intramuscular (IM) injection only, typically into the gluteus maximus (upper outer quadrant) or vastus lateralis. Use a 21-23 gauge needle, 1-1.5 inches long. Aspirate before injection to avoid intravascular administration. Rotate injection sites. The oil-based solution should be at room temperature before administration.
Testosterone is the primary endogenous androgen. Exogenous testosterone exerts its effects by binding to and activating the intracellular androgen receptor (AR). The hormone-receptor complex translocates to the nucleus, binds to specific DNA sequences (androgen response elements), and modulates the transcription of target genes, leading to the synthesis of proteins responsible for its effects.
Pregnancy: CATEGORY X. Absolutely contraindicated. May cause virilization of the external genitalia of the female fetus. Risk of teratogenicity is high.
Driving: Generally no effect. However, patients should be cautioned about potential mood alterations, aggression, or dizziness which may impair driving ability.
| Warfarin / Oral Anticoagulants | Testosterone may potentiate anticoagulant effect by increasing synthesis of clotting factors? Actually, it can increase or decrease effect unpredictably; more commonly, it increases risk of bleeding by unknown mechanisms. INR must be monitored closely. | Major |
| Corticosteroids (e.g., Prednisolone) | Enhanced risk of severe fluid retention and edema. | Major |
| Insulin, Oral Hypoglycemics | Testosterone may decrease blood glucose and insulin requirements. Monitor blood glucose closely. | Moderate |
| Cyclosporine, Tacrolimus | Testosterone may inhibit metabolism of these drugs, increasing risk of toxicity. Monitor drug levels. | Moderate |
| Propranolol | Testosterone may increase clearance of propranolol, reducing its effect. | Moderate |
| Oxyphenbutazone | Increased serum levels of oxyphenbutazone. | Moderate |
Same composition (Testosterone (250mg)), different brands: