title: Absolute bioavailability of testosterone after oral administration of testosterone-undecanoate and testosterone.
abstract: The plasma levels of testosterone (T) were measured after oral administration of 25 mg T and 40 mg testosterone-undecanoate (TU) in a group of young women by a specific radioimmunoassay. Plasma levels were compared to those after intravenous administration of 1.5 micrograms testosterone/kg to another group of young women for determination of absolute bioavailability. Due to the high metabolic clearance rate of 24.5 ml/min/kg absolute systemic availability of free testosterone was calculated to 3.56 +/- 2.45%. Oral administration of testosterone undecanoate leads only to an absolute testosterone bioavailability of 6.83 +/- 3.32%.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D005260:Female; D006207:Half-Life; D006801:Humans; D008657:Metabolic Clearance Rate; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D013739:Testosterone; C010792:testosterone undecanoate