Ozempic and Other GLP-1 Drugs Could Reduce Breast Cancer Risk by Up to 35%, New Study Reveals
In a groundbreaking discovery that has captivated both the oncology and wellness communities, a significant new study proposes that widely-used GLP-1 weight-loss drugs — such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) — could substantially decrease the risk of breast cancer in women.
The pivotal retrospective study, overseen by the American College of Radiology (ACR) and spearheaded by Dr. Elizabeth McDonald, MD, PhD, a professor of radiology at the University of Pennsylvania Perelman School of Medicine, scrutinized health records of over 111,000 women aged between 45 to 80 with a BMI of 25 or above. The findings, unveiled at the 2026 ASCO (American Society of Clinical Oncology) Annual Meeting and published in JCO Oncology Practice, revealed that women on GLP-1 medications had approximately 30% lower odds of developing breast cancer compared to non-users. Some analyses even suggested risk reductions as high as 35–47%.
Among the matched GLP-1 users, 1.62% developed breast cancer, as opposed to 2.31% of non-users — roughly translating to seven fewer cancers per 1,000 women. This association remained consistent across both Black and White women when analyzed separately.
The researchers propose that the protective effect could originate from GLP-1 drugs’ capacity to reduce inflammation and modify biological pathways associated with cancer development. These effects could potentially extend beyond their well-documented weight-loss benefits.
“While our study was observational and does not definitively confirm an association… it does add to the growing body of evidence suggesting that it’s worth investigating these weight-loss drugs as potential cancer prevention tools,” said Dr. McDonald.
The ACR is now advocating for funding for a large prospective clinical trial to validate these findings.
Source: Medscape – Two Studies Link GLP-1 Use to Lower Breast Cancer Risk, June 25, 2026