Insulin functions as a dimer and can form heterodimers with IGF-1, which can bind to receptors and alter metabolism.

“insulin does not bind as a monomeric hormone it's actually a dimer and it can be a heterodimer say you can have two insulins or you can have an insulin and igf-1 or you can have two IGF ones and they can bind to receptors and there are even hetero receptors where it's an insulin receptor and an igf-1 receptor each bound by their cognate ligands Derek Laroy at Mount Sinai has done kind of work for years and when you block these heterodimeric receptors you can completely alter metabolism”