Reference entry · IGFBP-resistant IGF-1 analog
IGF-1 LR3
Also known as: Long R3-IGF-1 · LR3-IGF-I · Long arginine 3-IGF-1
- Class
- IGFBP-resistant IGF-1 analog
- Size
- 83 amino acids
- Primary targets (literature)
- IGF-1 receptor (IGF-1R); reduced IGFBP binding
- Regulatory context
- Not FDA-approved. Prohibited in sport (WADA). Distinct from pharmaceutical mecasermin (rhIGF-1).
Overview
IGF-1 LR3 is an engineered IGF-1 analog with an Arg3 substitution and N-terminal extension that evades IGFBP sequestration. Widely used in cell culture and rodent research; no FDA approval and WADA-prohibited.
Mechanism in research literature
Reduced IGFBP affinity leaves more peptide free to activate IGF-1R, extending effective exposure vs. native IGF-1. Signals through PI3K/Akt and MAPK pathways in research models.
Common research focus areas
- Rodent anabolic and anti-catabolic infusion studies
- Cell-culture IGF-1R activation without IGFBP buffering
- Distinction from pituitary GH secretagogues and native IGF-1
- Disulfide integrity and MS identity for 83-mer supply
Full literature roundup
Read the cited research summary
A long-acting IGF-1 analog engineered for reduced IGFBP binding. GroPep-era pharmacology, preclinical anabolic literature, and strict identity requirements for an 83-mer.
IGF-1 LR3 research roundup · 5 minEvaluate catalog material
- COA literacy — read batch documentation before comparing vendors.
- Peptide identity testing — why sequence confirmation matters beyond purity %.
- How we vet sources — our score methodology for recommended vendors.