Explanation, Benefits, and Dosing for IGF LR3 Wittmer Rejuvenation Clinic IGF 1LR3 Advanced Anabolic Signaling & Muscle Growth What is IGF 1 LR3?, Insulin Like Growth Factor 1 Long R3 (IGF 1 LR3) is a modified version of IGF 1 with a longer half life, making it significantly more potent and effective for muscle growth, The mighty protein: insulin like growth factor type 1 The Physiological Society Muscle Growth Montreal Peptides Canada (PC)