Naturally postmenopausal women with hypoactive sexual desire disorder (HSDD) will be randomized into a 52-week, multicenter, double-blind (DB), parallel-group, placebo-controlled study. Patients will be stratified based on whether they use concomitant estrogen/progestin therapy and then randomized in a 4:1 ration to receive either testosterone transdermal system (300 mcg/day) or placebo. Patients using estrogen/progestin at the start of the study should maintain this therapy throughout the study; patients not using estrogen/progestin at the start of the study should not initiate estrogen/progestin therapy throughout the study. Endometrial biopsies and transvaginal ultrasounds will be collected/performed at screening and study exit for all patients. Safety will be assessed by adverse events, reports of vaginal bleeding, lipids, serum chemistry, and hematology. Physical exams, pap smears, and mammograms will be monitored.
