Growth Hormone SecretagoguesWADA Prohibited
IGF-1 LR3
Synonyms: Long R3 IGF-1, Long Arg3 Insulin-like Growth Factor-I
Sequence: MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA
Critical Safety & Regulatory Notice
IGF-1 LR3 is classified as a regulated, unapproved, or research-only substance. Doping/Regulatory Status: Not FDA approved. Strictly prohibited by WADA under Section S2.. Clinical safety profiles for human use are deficient or not approved.
History & Discovery Timeline
IGF-1 LR3 was engineered in the 1990s by GroPep (Australia) to create a more potent IGF-1 analog with reduced binding affinity to IGF-binding proteins (IGFBPs), leading to an extended half-life.
What it is: It is a synthetic 83-amino-acid analog of human IGF-1, containing an Arg substitution at position 3 and a 13-amino-acid N-terminal extension. It is classified under the Metabolic category.
Proposed Mechanisms & Research Findings: It activates the IGF-1 receptor but avoids binding to IGFBPs, resulting in dramatically increased biological activity and half-life to promote muscle hypertrophy and glucose transport.
Regulatory & Safety Status: It is not FDA approved for human therapeutic use. Gray-market sourcing carries high risks of contamination and severe hypoglycemic episodes.
Athletic & Anti-Doping Status: Strictly prohibited by WADA under Section S2. Use leads to long-term athletic suspensions.
Understanding IGF-1 LR3 Key Facts
Primary Target System:NEUROENDOCRINE
Residue Count / Length:1 Amino Acids
Primary Action & Category:IGF-1 Receptor Agonist (Growth Hormone Secretagogues)
Primary Receptors:IGF-1 Receptor (IGF-1R)
Figure 1: Detailed molecular mechanism pathways of IGF-1 LR3 (click to enlarge).