IGF-1 LR3

Overview

IGF-1 LR3 (Long R3 IGF-I) is a synthetic analog of insulin-like growth factor 1, described in the literature as an 83-amino-acid analog carrying an N-terminal 13-residue extension and an arginine-for-glutamic-acid substitution at position 3. Those changes give it reduced affinity for the IGF-binding proteins and therefore a longer active life in research models than native IGF-1. It is studied in muscle-growth, protein-synthesis, tissue-repair, and cell-signaling research, where its activity is attributed to the IGF-1 receptor, cross-talk with the insulin receptor, and the downstream PI3K-Akt and MAPK pathways. It has also been examined in glucose-related and body-composition research. Human evidence remains limited and mixed, and the only FDA-approved IGF-1 therapy (mecasermin) is a different molecule cleared solely for specific pediatric growth-failure indications, not for general therapeutic use. It is offered here for research use only.

Research highlights

• A synthetic analog of insulin-like growth factor 1 (Long R3 IGF-I)
• Described as an 83-amino-acid analog with an N-terminal extension and a position-3 substitution
• Modified for reduced affinity to IGF-binding proteins and a longer active life in research models
• Studied for its role in muscle-growth and protein-synthesis pathways
• Investigated in models of tissue repair and cell signaling via the IGF-1 receptor and PI3K-Akt and MAPK pathways
• Explored in glucose-related and body-composition research, where human evidence stays limited and mixed