IGF-1 LR3 (Long Arg3 IGF-1) is a modified analogue of Insulin-Like Growth Factor-1 with a substitution at
position 3 (arginine for glutamic acid) and a 13-amino acid extension. This modification reduces its binding to
IGF-binding proteins, dramatically extending its half-life to approximately 20–30 hours compared to the 12–
15 minutes of native IGF-1. It promotes muscle growth, fat loss, and cellular repair through direct IGF-1
receptor activation.
Key Benefits
• Potent anabolic effect — stimulates muscle cell proliferation and differentiation
• Dramatically extended half-life vs native IGF-1 (20–30 hours)
• Promotes fat oxidation and lean body composition
• Enhances nutrient uptake into muscle cells
• Supports connective tissue repair and recovery
