Testosterone (1% w/w) is a topical gel formulation of the primary endogenous androgen hormone. It is used for testosterone replacement therapy (TRT) in males with confirmed hypogonadism. The 1% w/w concentration delivers a controlled dose through transdermal absorption, aiming to restore physiological serum testosterone levels, improve symptoms of deficiency, and maintain secondary sexual characteristics. In the Indian context, it is a Schedule H prescription drug, requiring strict monitoring due to potential for misuse and abuse.
Adult: Initial dose: 5 g of gel (delivering 50 mg testosterone) applied once daily. Dose must be individualized based on serum testosterone levels measured 2-8 hours after application, typically after 2 weeks. Usual dose range: 2.5 g to 10 g (25 mg to 100 mg testosterone) daily.
Note: Apply to clean, dry, intact skin on shoulders, upper arms, or abdomen. Do not apply to genitals. Wash hands thoroughly with soap and water after application. Allow gel to dry for 3-5 minutes before dressing. Cover application site with clothing to prevent transfer. Avoid swimming, showering, or washing the site for at least 5-6 hours after application.
Testosterone is the primary male sex hormone. Exogenous testosterone supplementation binds to and activates 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 responsible for the development and maintenance of male sexual characteristics, anabolic effects, and feedback regulation of the hypothalamic-pituitary-gonadal (HPG) axis.
Pregnancy: CATEGORY X. Contraindicated. May cause virilization of the female fetus. Women of childbearing potential must avoid skin contact with application sites on male patients.
Driving: No direct effect. However, patients should be cautious if experiencing dizziness, headaches, or visual disturbances.
| Warfarin | Testosterone may potentiate anticoagulant effect, increasing INR and bleeding risk. | Major |
| Corticosteroids (e.g., Prednisolone) | Increased risk of fluid retention and edema. | Moderate |
| Insulin, Oral Hypoglycemics | Testosterone may decrease blood glucose; monitor glucose levels as dose adjustment may be needed. | Moderate |
| Cyclosporine, Tacrolimus | Testosterone may increase levels of these immunosuppressants, increasing toxicity risk. | Major |
| Propranolol | Testosterone may increase its clearance, reducing its effect. | Moderate |
| ACTH or Corticosteroids | May enhance edema. | Moderate |
Same composition (Testosterone (1% w/w)), different brands: