Popular Weight-Loss Drugs Linked to 30 Percent Reduction in Breast Cancer Risk, New Study Finds

Women who take GLP-1 medications — the class of drugs behind popular weight-loss treatments like Ozempic and Wegovy — may be significantly less likely to develop breast cancer, new research suggests. The study, led by Dr. Elizabeth McDonald, a professor of radiology at the University of Pennsylvania’s Perelman School of Medicine, analyzed health records from more than 110,000 women aged 45 to 80. It found that those prescribed GLP-1 medications were roughly 30 percent less likely to be diagnosed with breast cancer than those who were not.“While our study was observational and does not definitively confirm an association between GLP-1 medications and reduced breast cancer incidence, it does add to the growing body of evidence suggesting that it’s worth investigating these weight-loss drugs as potential cancer prevention tools,” Dr. McDonald said in a paper presented at the 2026 American Society of Clinical Oncology annual meeting.Researchers examined two groups: a full cohort of 111,646 women with a BMI of 25 or above, and a matched cohort of 30,528 women, carefully controlled for age, race, ethnicity, BMI, breast density, and diabetes status. The reduced breast cancer risk held across both groups — 35.1 percent lower odds in the full analysis and 30.5 percent in the matched cohort.GLP-1 medications work by mimicking a natural hormone that regulates blood sugar and appetite. Originally developed to treat type 2 diabetes, they are now widely used for weight management. Researchers believe their cancer-related benefits may go beyond weight loss alone. The drugs reduce systemic inflammation, a known contributor to cancer development, and have additional metabolic and epigenetic effects that may inhibit tumor growth.Current options for breast cancer prevention beyond regular screening are limited. While tamoxifen is effective, many eligible patients avoid it due to its side effects. Prophylactic mastectomy, while recommended for some high-risk patients, is a major surgical intervention. GLP-1 medications, by contrast, are already used by millions of Americans. Dr. McDonald and her team are now working to launch a multisite clinical trial to formally assess whether GLP-1 medications can reduce breast cancer incidence in high-risk women, including those with a prior breast cancer diagnosis.The breast cancer findings build on a wider body of emerging research linking GLP-1s to reduced risk across multiple cancer types. Separate research presented at the 2026 ASCO Gastrointestinal Cancers Symposium found lower rates of colorectal cancer among GLP-1 users.Earlier studies also suggest possible benefits for cancers of the liver, pancreas, gallbladder, esophagus, ovaries, and uterus. Researchers believe the drugs may help starve cancer cells by lowering insulin and blood sugar levels, while also boosting immune cell activity. However, GLP-1s are not currently approved for cancer prevention, and experts stress that large-scale clinical trials are still needed before any firm conclusions can be drawn.

Popular Weight-Loss Drugs Linked to 30 Percent Reduction in Breast Cancer Risk, New Study Finds

More from the New York Sun

President Xi, Courting North Korea’s Kim Jong-un at Pyongyang, Is Likely To Play Moscow Against Washington

A New Museum Hidden Beneath the Lincoln Memorial Opens June 25

Noël Coward, Back in Fashion on Stage

Do the Democrats Want the Iranian Dictatorship To Win?

Lamar Alexander Offers a Welcome Break From Today’s Glue-Factory Politics

Scientists Unveil New Rules for Announcing Alien Contact — Including a Strict ‘No Reply’ Order

USDA Rushes Experts to Texas Following Second Confirmed Screwworm Case

Bot Traffic Surpasses Human Activity Online for the First Time