OTP EXCLUSIVE: What the New FDA Breastfeeding Study Means for Moms on Zepbound and Mounjaro

Dave Knapp
21 hours ago
2 min read

We have included the links to the new FDA updates.

Original posted at obesity.news/ on Sep 29, 2025

Sometimes, the things patients have been saying all along finally get written into the fine print. A Breakthrough for Breastfeeding Moms this week when the FDA updated the official labels for Mounjaro and Zepbound.

For years, mothers have asked the same question: If I’m on tirzepatide, can I safely breastfeed?

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Until now, nobody had a clear answer. The FDA required Lilly to study it, and the results are finally in. Researchers gave tirzepatide to lactating women and then measured their breastmilk.

FDA Label (Sept 2025):“Following subcutaneous administration of a single 5 mg dose to 11 healthy lactating adult females, the concentration of tirzepatide in breast milk was found to be undetectable in 164 of 171 samples. The cumulative amount detected in the remaining 7 samples over 28 days was equivalent to less than 0.02% of the maternal dose. The last measurable concentrations occurred 5 days post-dose.

That is a tiny amount. Practically negligible.

This does not mean we know every long-term effect. It does mean the medicine barely makes its way into breastmilk. For women who have felt forced to choose between their own health and nourishing their child, this is a step toward reassurance. It is not a final answer, but it shows science is catching up to your lived reality.

What You Can Do With This Information

Bring it to your doctor or pediatrician. Share the FDA label update so you can make an informed decision together.
Know the risk is low but not zero. Most of the time, tirzepatide won’t show up in breastmilk at all.
Weigh your health too. Treating diabetes or obesity is not just about you, it also affects your ability to show up for your baby.

(View the FDA Docs)

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