Determination of Tirzepatide (Mounjaro) in Human Breastmilk Following Dosing

Background: There is typically little information available to postpartum moms and their healthcare professionals about the safety of medication therapy during breastfeeding. Concurrently, pregnancy may cause a persistent rise in weight, and obesity may have detrimental effects on one's physical and mental health, perhaps leading to postpartum depression. Our research attempts to protect the health and safety of nursing women and their breastfed children by examining the transfer of Tirzepatide into human milk.

Methods: Tirzepatide quantification was done using high-resolution liquid chromatography-mass spectrometry. Samples were collected from the InfantRisk Center Human Milk biorepository, which contained milk samples from five women collected at 0, 12, 24, 48 hours, and day 7 post-tirzepatide administration. Trizepatide was extracted using protein precipitation in methanol, followed by chromatographic separation utilizing a reversed-phase (C-18) column. A gradient elution method was employed using Orbitrap mass spectrometry. Linear calibration curves were observed for the method between 1-50 ng/mL Tirzepatide, and the method’s limit of detection was 3.6 ng/mL.

Results: Most milk samples gave very small signals consistent with a Tirzepatide peak at tr = 14.3 minutes. The peak areas noted for samples basically straddle the technical limit of detection (3.6 ng/mL), and all samples were below the LLOQ (12 ng/mL).

Conclusion: These findings imply that the non-detectable amounts of Tirzepatide in human milk samples allay worries about Tirzepatide exposure during breastfeeding. These results support the data-driven judgments made by healthcare professionals on postpartum treatment interventions.