DHT concentrations increased in parallel with testosterone concentrations at AndroGel 1% doses of 50 mg/day and 100 mg/day, but the DHT/T ratio stayed within the normal range, indicating enhanced availability of the major physiologically active androgen. Serum estradiol (E2) concentrations increased significantly within 30 days of starting treatment with AndroGel 1% 50 or 100 mg/day and remained elevated throughout the treatment period but remained within the normal range for eugonadal men. Serum levels of SHBG decreased very slightly (1 to 11%) during AndroGel 1% treatment. In men with hypergonadotropic hypogonadism, serum levels of LH and FSH fell in a dose- and time-dependent manner during treatment with AndroGel 1%.
Testim® was evaluated in a randomized multicenter, multi-dose, active and placebo controlled 90-day study in 406 adult males with morning testosterone concentrations ≤ 300 ng/dL. The study was double-blind for the doses of Testim and placebo, but open label for the non-scrotal testosterone transdermal system. During the first 60 days, patients were evenly randomized to Testim 50 mg, Testim 100 mg, placebo gel, or testosterone transdermal system. At Day 60, patients receiving Testim were maintained at the same dose, or were titrated up or down within their treatment group, based on 24-hour averaged serum testosterone concentration obtained on Day 30.