Large Study Links GLP-1 Medications to Lower Breast Cancer Risk in Women

A large-scale study published in June 2026 found that women using GLP-1 receptor agonist medications, including semaglutide, had a measurably lower rate of breast cancer diagnoses compared to a matched group of women who did not take the drugs.

The study tracked more than 100,000 women over three years, drawing on insurance claims data and cancer registry records. Women taking GLP-1 medications showed a roughly 25 percent lower rate of new breast cancer diagnoses after adjusting for age, body mass index, and other risk factors.

Researchers said the mechanism is not fully understood but may involve the drugs' effects on insulin levels, inflammation, and fat tissue, all of which are known to influence breast cancer risk. GLP-1 medications lower blood sugar by stimulating insulin release and reducing appetite, and they have been shown to reduce systemic inflammation in earlier studies.

Dr. Michael Torres, an oncologist at a major academic medical center who was not involved in the study, called the findings "worth taking seriously" but cautioned against drawing firm conclusions from observational data. "We need randomized trials to know whether this is a real protective effect or a result of other differences between the groups," he said.

The study adds to a growing list of potential benefits associated with GLP-1 drugs beyond their approved uses for diabetes and obesity. Earlier research has linked the medications to reduced cardiovascular events, lower rates of kidney disease progression, and, in some studies, improvements in mental health symptoms.

The findings were published in a peer-reviewed medical journal and are expected to prompt further research into GLP-1 drugs as a potential tool in cancer prevention.