Wait, GLP-1s Might Also Reduce Breast Cancer Risk?

I speak about this so often it probably makes people uncomfortable, but I lost one of my very best friends to breast cancer six years ago, at the way-too-tender age of 31. I also have an ATM gene mutation that gives me a 20% lifetime risk of the disease. Fun, I know.

That's why, when news broke out of the 2026 ASCO Annual Meeting (the largest oncology conference of the year) this week, I had to put my phone down for a second. Researchers from the University of Pennsylvania analyzed data from over 110,000 women and found that those taking GLP-1s (Ozempic, Wegovy, that whole family) were up to 30-35% less likely to develop breast cancer than those who weren't. A separate abstract looked specifically at high-risk women and the signal held there, too.

Here's the nuance, though, because it matters (and because I can't not): the main study is observational and retrospective, meaning it shows correlation, not causation. The women analyzed were overweight, ages 45 to 80, which isn't a perfect stand-in for every woman reading this. Researchers are now pushing to launch a prospective clinical trial, which is the gold standard this data hasn't reached yet.

But what I keep coming back to is this: we've spent decades watching women's health research move slowly and carefully while women like Lisa ran out of time. This isn't a green light to start a medication you don't need. And yet — it's news worth paying attention to, and a reason to keep asking your doctor the uncomfortable questions.

I don't need it to be definitive; I just need it to be the beginning of something.