Anabolic & Muscle Building

IGF-1 LR3

Also known as: Insulin-like Growth Factor-1 Long R3 · Long-R3 IGF-1

The most potent anabolic peptide for muscle growth and recovery.

Half-Life
~20–30 hours (vs 12–15 minutes for native IGF-1)
Administration
Subcutaneous injection
Category
Anabolic & Muscle Building
Citations
1 studies

What is IGF-1 LR3?

IGF-1 LR3 (Insulin-like Growth Factor-1 Long R3) is a modified version of IGF-1 with an arginine substitution at position 3 and a 13-amino acid extension at the N-terminus. These modifications prevent binding to IGF-binding proteins (IGFBPs), dramatically extending its half-life and potency compared to native IGF-1.

Mechanism of Action

IGF-1 LR3 binds to IGF-1 receptors throughout the body, activating the PI3K/Akt/mTOR pathway for protein synthesis and muscle growth, stimulating satellite cell activation and differentiation (muscle stem cells), promoting glucose uptake in muscle (insulin-like effects), and inhibiting apoptosis in muscle cells.

IGF-1 LR3 Dosing Protocol

50–100 mcg subcutaneous or intramuscular injection post-workout, daily for 4 weeks maximum. Inject into the trained muscle group for local hyperplasia. Cycle: 4 weeks on, 4–6 weeks off (to prevent receptor desensitization and insulin resistance).

Administration Routes
Subcutaneous injectionIntramuscular injection
Half-Life
~20–30 hours (vs 12–15 minutes for native IGF-1)

Want a personalized protocol? Tell PepBot your goals, health status, and experience level for a custom IGF-1 LR3 protocol.

IGF-1 LR3 Benefits

Muscle hyperplasia (new muscle cell creation)
Accelerated muscle recovery
Enhanced protein synthesis
Fat loss
Improved nutrient partitioning
Tendon and ligament strengthening
Anti-aging effects

Side Effect Profile

Hypoglycemia (low blood sugar — most important risk, always inject post-meal or have carbs ready), joint pain at high doses, potential for tumor growth promotion (avoid if cancer history), insulin resistance with prolonged use.

IGF-1 LR3 Stacking Guide

IGF-1 LR3 works synergistically with these compounds. Click any to learn more, or ask PepBot to build you a complete stack.

Research & Citations

Frequently Asked Questions about IGF-1 LR3

What is the difference between IGF-1 LR3 and regular IGF-1?
IGF-1 LR3 has a 20–30 hour half-life vs 12–15 minutes for native IGF-1. The LR3 modification prevents binding to IGFBPs (binding proteins that neutralize IGF-1), making it 2–3x more potent. It's also more stable and practical for research use.

Still have questions about IGF-1 LR3?

PepBot has encyclopedic knowledge of IGF-1 LR3 — dosing, stacking, interactions, latest research, and personalized protocols. Ask anything.