IgG1λ human monoclonal antibody that is used for the treatment of lupus erythematosus. At latest update no published data on excretion into breast milk were found. Because a high molecular weight, excretion into breast milk makes is unlikely. Its protein-like composition would facilitate its destruction in the stomach, thus preventing the infant intestinal absorption, except in preterm and immediate neonatal period in which they may have an increased intestinal permeability. The European League Against Rheumatism (EULAR) does not recommend against breastfeeding on mothers treated with Belimumab, if no other therapeutic alternative is available.