Glatiramer Acetate

A synthetic 4-amino acid polypeptide (L-alanine, L-glutamic acid, L-lysine, and L-tyrosine) similar to myelin, indicated for relapsing multiple sclerosis ^{(Ziemssen 2001)}. Administered subcutaneously daily or three times a week.

As of the last update, we found no published data on its excretion into breast milk, but it is considered unlikely due to its rapid degradation into amino acids following subcutaneous injection and its undetectable levels in patients’ plasma, urine, or feces. Furthermore, its high molecular weight makes excretion into milk unlikely. ^{(Fragoso 2013)}

In the event that a small amount of peptides were to pass into breast milk, due to their protein nature, they would be destroyed in the infant’s stomach and not absorbed; therefore, their oral bioavailability is practically zero, except in preterm infants and during the immediate neonatal period, when there may be greater intestinal permeability. ^{(Almas 2016, Cree 2013)}

No problems have been observed in infants breastfed for periods ranging from 1 to 12 months by mothers receiving glatiramer.. ^{(Kaplan 2025 y 2022, Ciplea 2022, Fragoso 2013 y 2010, Hellwig 2012 y 2011).}

Serious side effects are rare. Glatiramer is considered a safe medication during breastfeeding by most experts and clinical practice guidelines ^{(Shipley 2025, Pul 2025, Witt 2024, Krysko 2023, Ciplea 2023, Sánchez-Velasco 2023, Collorone 2022, Kaplan 2022, Dobson 2021, Freedman 2020, Langer 2019, Fragoso 2013)}, as well as by the manufacturer ^{(AEMPS-TEVA 2025)}. No interval needed between injection and next breastfeeding. ^{(Krysko 2023)}