IGF-1 LR3 stands for Insulin-Like Growth Factor-1 Long Arg3, and it's widely used for muscle building and fat loss. It works by promoting the growth and regeneration of muscle cells, helping the body repair faster and develop lean mass. Because of its powerful growth-promoting effects, it's often used by bodybuilders and athletes during cutting or bulking phases. This peptide is popular because it stays active in the body longer than regular IGF-1, allowing for more noticeable results in a shorter amount of time. Users often report enhanced strength, better endurance, and visible improvements in body composition with consistent use.