“GLP-1s cause infertility.”
What the evidence shows
The evidence points opposite to the fear. Weight loss can restart ovulation in women who weren't ovulating because of obesity or PCOS, and a 2023 meta-analysis of PCOS trials found a higher natural pregnancy rate with GLP-1 treatment. Reproductive-safety fact sheets (e.g., MotherToBaby) note it is not known that semaglutide harms fertility, and the well-documented 'Ozempic babies' pattern is unexpected pregnancies — the signature of returning fertility, not lost fertility.
What we still don’t know
There's no long-term human study formally measuring fertility as an outcome after GLP-1 use, so a subtle effect can't be fully excluded, and the reproductive data in PCOS are low-certainty. Rapid weight loss itself can temporarily disrupt cycles in some people, which is a different phenomenon from the drug causing infertility, and one that hasn't been cleanly separated in studies.
Why the claim misleads
'Cause infertility' states a harm the evidence doesn't show and that mostly contradicts what's observed — surprise pregnancies, not barren cycles. It likely borrows fear from the (separate and valid) rule that these drugs shouldn't be used during pregnancy. The honest framing is nearly the reverse: for some people fertility returns, which is itself a reason to sort out contraception and conception timing with a clinician before starting.
Graded by The Peptide Era · evidence, not hype