IGF-1 DES

A naturally occurring truncated variant of insulin-like growth factor-1 lacking the first three N-terminal amino acids (Gly-Pro-Glu), yielding a 67-residue peptide (CAS 112603-35-7). The truncation drastically reduces affinity for IGF-binding proteins (IGFBP-3, -5) while preserving IGF-1-receptor binding, resulting in a higher free-active fraction and greater local potency than native IGF-1. Studied in preclinical muscle-hypertrophy and wound-healing models; not FDA-approved.