No information is available on the clinical use of lixisenatide during breastfeeding. Because lixisenatide is a large peptide molecule with a molecular weight of 4858 daltons, the amount in milk is likely to be very low and absorption is unlikely because it is probably destroyed in the infant's gastrointestinal tract. Until more data become available, lixisenatide should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant.