Women taking GLP-1 medications such as Ozempic and Wegovy showed about 30 percent lower odds of developing breast cancer in a large observational study.
Researchers reviewed electronic health records from more than 111,000 women aged 45 to 80 with a body mass index of 25 or higher who underwent breast imaging at Penn Medicine between January 2022 and June 2025. Those prescribed GLP-1 drugs had 35.1 percent lower odds of breast cancer in the full group and 30.5 percent lower odds in a matched analysis. The findings were presented at the 2026 American Society of Clinical Oncology Annual Meeting and published in JCO Oncology Practice. Elizabeth McDonald, a professor at the University of Pennsylvania Perelman School of Medicine, noted that the study was observational and does not prove causation. McDonald and colleagues plan to launch clinical trials to test whether GLP-1 drugs can help prevent breast cancer in high-risk women. The medications affect pathways linked to cancer development, though weight loss may also contribute to the observed benefit.
