IGF-1 LR3 Peptide  Research Peptides

IGF-1 LR3 (Long Arginine 3 Insulin-like Growth Factor-1) is a high-potency, long-acting analog of human IGF-1, engineered for extended bioactivity and enhanced receptor signaling. Designed to evade IGF-binding protein sequestration, it delivers sustained anabolic effects in muscle, bone, and metabolic research models. Ideal for investigators studying hypertrophy, satellite cell activation, and tissue regeneration.

Product Overview

IGF-1 LR3 is an 83-amino acid synthetic peptide modified with an arginine substitution at position 3 and a 13-amino acid N-terminal extension. These structural changes reduce binding to IGF-binding proteins (particularly IGFBP-3), extending its half-life to 20–30 hours and increasing potency approximately 3-fold compared to native IGF-1.peptideinitiative+2

By maintaining high bioavailability and free receptor engagement, IGF-1 LR3 activates the PI3K-Akt-mTOR and MAPK pathways, driving protein synthesis, cellular proliferation, and glucose uptake. This makes it a cornerstone compound for skeletal muscle biology, regenerative medicine, and metabolic signaling research.peptideinitiative+2

Key Research Applications

• Muscle Hypertrophy – Satellite cell activation, myofibrillar protein synthesis, fiber growth.swolverine+2

• Tissue Repair – Accelerated recovery from muscle injury, tendon remodeling, collagen deposition.americanwellnesspharmacy+1

• Metabolic Optimization – Enhanced glucose uptake, insulin sensitivity, nutrient partitioning.youtubeamericanwellnesspharmacy

• Cell Proliferation – Cancer biology, tissue engineering, developmental studies.peptidehackerlab+2

Mechanism of Action

IGF-1 LR3 binds directly to the IGF-1 receptor (IGF-1R), a transmembrane tyrosine kinase, triggering autophosphorylation and downstream signaling:

• PI3K-Akt-mTOR pathway – Promotes protein synthesis, cell survival, glucose metabolism.peptideinitiative+2

• MAPK/ERK pathway – Drives cellular proliferation, differentiation, and satellite cell activation.palmettopeptides+1

Unlike native IGF-1, IGF-1 LR3 largely bypasses IGFBP sequestration, maintaining elevated free fractions and prolonged receptor engagement in serum-containing environments.peptides+2

Research Benefits (Preclinical Evidence)

• Increases lean muscle mass and strength via direct anabolic signaling.peptideinitiative+1

• Enhances recovery from exercise-induced muscle damage and injury.peptidedeck+1

• Activates satellite cells, enabling hyperplasia and long-term growth capacity.ascendpeptide+1

• Supports metabolic health through improved insulin sensitivity and glucose utilization.