IGF-1 DES 1,3 — 1 mg

The established literature name des(1–3)IGF-I denotes an IGF-I molecule lacking its first three amino-terminal residues. This truncation changes its interaction with IGF-binding proteins, which normally influence how much growth factor is available to receptors. In a 1989 experimental paper, investigators compared IGF-I, IGF-II, and des(1–3)IGF-I in cell systems and found that binding proteins inhibited the intact growth factors more effectively than the truncated analogue. That distinction helps explain why DES material can appear more active in a particular culture environment.

A 1992 study of cultured rat granulosa cells likewise used des(1–3)IGF-I to investigate endogenous binding-protein inhibition. Under binding-protein-rich conditions, the truncated analogue more strongly supported an FSH-associated progesterone response than intact IGF-I. These are defined laboratory outcomes, not a universal potency multiplier applicable to every tissue or species. The shorter requested label “IGF-DES 1,3” does not independently specify an IGF family member, although des(1–3)IGF-I is the recognizable research usage. Product identity should therefore be confirmed as the IGF-I truncation before treating this description as an exact molecular match.