Comparative Pharmacology
Head-to-head clinical analysis: TESTIM versus TESTOSTERONE UNDECANOATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TESTIM versus TESTOSTERONE UNDECANOATE.
TESTIM vs TESTOSTERONE UNDECANOATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Testosterone replacement therapy; binds to and activates androgen receptors, modulating gene expression leading to male sexual development and maintenance of secondary sexual characteristics.
Testosterone undecanoate is a prodrug of testosterone, which binds to androgen receptors (ARs) in target tissues, leading to activation of androgen-responsive genes that promote male sexual development, maintenance of secondary sexual characteristics, and anabolic effects. It also exerts negative feedback on the hypothalamic-pituitary-gonadal axis, suppressing gonadotropin secretion.
Apply 5 g (1 tube) of 1% gel to clean, dry, intact skin of the shoulders, upper arms, or abdomen once daily, preferably in the morning. Dosage may be adjusted to 10 g (2 tubes) depending on clinical response. Apply immediately after opening and avoid bathing or swimming for at least 30 minutes.
1000 mg intramuscularly every 10-14 weeks, followed by a second dose at 6 weeks; maintenance 1000 mg every 10-14 weeks.
None Documented
None Documented
Terminal elimination half-life of testosterone from serum is approximately 10-100 minutes after intravenous administration, but after transdermal application of Testim, the apparent half-life is longer (around 1-2 hours) due to continued absorption from the skin depot. The half-life of active metabolites (e.g., dihydrotestosterone) is about 2-3 hours.
Terminal elimination half-life: 20.7 days (range 16.5–25.7 days) after intramuscular injection. This prolonged half-life is due to slow release from the oily depot in muscle. With oral administration, half-life is approximately 7–13 hours.
Testosterone is primarily excreted in urine as glucuronide and sulfate conjugates (approximately 90%), with about 6% excreted in feces via bile. Less than 1% is excreted unchanged.
Renal (5-10% as glucuronide and sulfate conjugates, <1% as unchanged testosterone), Fecal (90% as metabolites via bile). No significant biliary excretion of active drug.
Category C
Category D/X
Androgen
Androgen