Ligand/receptor complexes formed at the plasma membrane are internalised via various endocytic pathways that influence the ultimate signalling output by regulating the complex's selection of interaction partners along the trafficking route. We report that in differentiated cells Activin A/receptor complexes are internalised via Clathrin-mediated endocytosis (CME) and macropinocytosis (MP), whereas in human embryonic stem cells (hESCs) internalisation occurred via CME. We further show that hESCs are devoid of MP, which becomes functional upon differentiation towards endothelial cells through mesoderm mediators. Our results reveal, for the first time, that MP is an internalisation route of Activin A in differentiated cells, which is not active in hESCs and is induced as cells differentiate.