An 83-residue synthetic analogue of insulin-like growth factor 1, comprising the native IGF-1 sequence with an Arg substitution at position 3 and a 13-residue N-terminal extension. These modifications reduce affinity for IGF-binding proteins (IGFBPs) and extend plasma half-life. Characterised as an agonist at the IGF-1 receptor. Lyophilised, HPLC-verified, COA supplied with every batch. For laboratory research use only. Not for human consumption.