“It's fine to use GLP-1s while breastfeeding.”
What the evidence shows
There is very little human data on GLP-1 drugs during breastfeeding. Reproductive-safety resources and product labels reflect that uncertainty: for injectable semaglutide, reproductive-safety resources note it is not expected to harm a breastfed infant but stress the data are limited — while the oral form (Rybelsus) is the one specifically advised against, for its absorption enhancer rather than the peptide. A single-dose lactation study of tirzepatide found the drug at undetectable or low levels in breast milk, and because these are large peptides they are expected to be poorly absorbed from an infant's gut — but 'plausibly low exposure' is not the same as demonstrated safety.
What we still don’t know
No adequate studies establish whether ongoing GLP-1 use is safe for a nursing infant, whether meaningful amounts reach milk with repeated dosing, or what effects (if any) that could have. Guidance also differs by product — at least one oral formulation is advised against in nursing because of an absorption-enhancer ingredient rather than the peptide itself.
Why the claim misleads
'It's fine' asserts a safety conclusion the evidence doesn't support — absence of data is not evidence of safety. There's also a separate wrinkle: weight loss isn't usually a priority while establishing breastfeeding. Because the specifics genuinely vary by product and situation, this is a decision to make with the prescriber using the exact product's label, not something to settle from a general claim online.
Source: MotherToBaby (OTIS) Fact Sheet — Semaglutide (limited breastfeeding data; label caution)
Graded by The Peptide Era · evidence, not hype