Five hundred eleven postmenopausal women with osteoporosis were randomized to receive daily transdermal abaloparatide (abaloparatide-sMTS; n=256) or subcutaneous abaloparatide (abaloparatide-SC; n=255) for 12 months. The primary outcome was percentage change in lumbar spine bone mineral density (BMD). Secondary outcomes included changes in total hip and femoral neck BMD, bone turnover markers, dermatologic safety, and clinical fracture incidence. Outcomes were assessed at 3, 6, and 12 months. Overall, the results revealed that while both groups experienced clinically meaningful increases in BMD, abaloparatide-sMTS did not meet the noninferiority margin compared to SC administration. Transdermal delivery was safe and generally well tolerated, suggesting it may still offer a viable alternative for patients reluctant to use injections.