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Supplement Monograph

IGF-1 DES

PeptideAnabolic

IGF-1 DES (des(1-3)IGF-1) is a truncated, more potent analog of insulin-like growth factor 1 misused for localized muscle growth; it has no human trials and is not an approved drug or supplement.

Work in progress Updated July 2026

What Is IGF-1 DES?

IGF-1 DES (“des(1-3)IGF-1”) is a naturally occurring truncated form of insulin-like growth factor 1, missing the first three N-terminal amino acids, which makes it bind poorly to IGF-binding proteins and therefore act as a more potent — but shorter-acting — growth factor than intact IGF-1. In the bodybuilding market it is promoted for “localized” or “site-specific” muscle growth, on the reasoning that its short half-life keeps its action near the injection site. It is a research protein, not an approved drug or dietary supplement, and there are no human efficacy trials for muscle growth.

Evidence

The defining property of des(1-3)IGF-1 — greater potency than intact IGF-1 due to reduced IGF-binding-protein sequestration — is documented in cell/animal work: in cultured rat anterior pituitary cells, des(1-3)IGF-I was roughly an order of magnitude more potent than IGF-I at affecting growth hormone and IGF-binding-protein secretion, attributed to its decreased binding by IGFBPs 1Reference 1The effects of insulin-like growth facto et al. · 1991In vitrohttps://pubmed.ncbi.nlm.nih.gov/1715381/View study →. This confirms the pharmacological rationale but says nothing about safe, effective muscle growth in people. I found no human trial of IGF-1 DES for hypertrophy, body composition, or “localized” muscle growth in this pass — that use is off-label/anecdotal, and the idea that it produces meaningful site-specific muscle gain in humans is unproven here.

Dosage & Safety

There is no established human dose for IGF-1 DES; regimens circulating online are not from controlled human trials, and this page makes no dosing recommendation. As a potent growth factor it carries pharmacological risks — including hypoglycaemia and the theoretical concern that stimulating cell proliferation could promote growth of existing tumours — none quantified for this compound in this pass. It is not an approved drug or supplement and is prohibited in sport. Human safety, long-term effects, drug interactions, and pregnancy/lactation safety are not established. This entry is informational only and is not an endorsement of use.

References

  1. The effects of insulin-like growth factor-I (IGF-I), IGF-II and des(1-3)IGF-I, a potent IGF analogue, on growth hormone and IGF-binding protein secretion from cultured rat anterior pituitary cells — in vitro / rat study. J Endocrinol (1991). https://pubmed.ncbi.nlm.nih.gov/1715381/