Biosynthetic erythropoietins are almost clinically indistinguishable from the natural form of erythropoietin, which is a normal component of breast-milk. They will not be absorbed from milk by the infant and therefore present no risk to the breastfed infant.
Drugs used to treat iron overload form large complexes with maternal iron which will be poorly absorbed by the infant. However, deferiprone should be avoided with breastfeeding as it has been shown to cause neutropenia in normal adult use.