Crucial role of androgen receptor in resistance and endurance trainings induced muscle hypertrophy through IGF 1 IGF 1R PI3K Akt mTOR pathway Nutrition & Metabolism Springer Nature Link IGF LR3 Natural Med Doc QK041 Recombinant human bovine porcine IGF 1 LR3 protein IGF 1 LR3 Superior Peptide IGF 1 LR3 tells your muscle cells to grow, repair, and absorb nutrients better. It works directly at the muscle level to help you build lean muscle and recover faster.What it is IGF 1