IGF-1 LR3 – Research-Grade Insulin-Like Growth Factor-1 Analog (Long Arg³)
IGF-1 LR3 (Insulin-Like Growth Factor-1 Long Arg³) is a recombinant polypeptide analog of native human IGF-1 that incorporates a substitution of arginine at position 3 along with an extended N-terminal sequence. These structural modifications alter binding interactions with endogenous IGF-binding proteins and distinguish IGF-1 LR3 from unmodified IGF-1. In laboratory research settings, IGF-1 LR3 is utilized as a reference material for studying IGF-related receptor interactions, signaling cascades, and comparative structure–activity relationships within insulin-like growth factor pathways.
Unlike short synthetic peptides, IGF-1 LR3 is a larger, disulfide-bonded polypeptide that more closely resembles protein-scale signaling molecules. This distinction allows researchers to examine receptor-mediated signaling dynamics, downstream phosphorylation events, and protein–protein interactions associated with IGF systems. Its defined amino acid sequence and recombinant production support consistent use in mechanistic assays, cellular signaling studies, and exploratory biochemical research conducted under controlled laboratory conditions.
Related research compounds
Follistatin 344 · ACE-031 · CJC-1295 (No DAC) · Ipamorelin · Sermorelin · HGH Frag 176-191
Documentation and methods
Analytical testing · How to read a COA · Batch COAs · Storage and handling · What are research peptides

