IGF-1 LR3
A long-acting modified analog of insulin-like growth factor 1 with extended half-life and reduced binding-protein affinity.
Overview
IGF-1 LR3 (Long R3 IGF-1) is a synthetic analog of human IGF-1 with a 13-residue N-terminal extension and an arginine substitution at position 3. These modifications dramatically extend its half-life and reduce binding to IGF-binding proteins, leaving more free, biologically active hormone.
Benefits
- Direct anabolic signaling at IGF-1 receptors
- Supports muscle hypertrophy
- Promotes satellite cell activation
- May aid recovery between sessions
Mechanism of Action
IGF-1 LR3 binds IGF-1 receptors on muscle and other tissues, activating the PI3K/Akt pathway that drives protein synthesis, cell proliferation, and inhibits apoptosis.
Dosage (informational only)
- Typical range
- 20–50 mcg per day
- Frequency
- Once daily, often pre- or post-workout
Hypoglycemia risk — keep glucose available. Long-term safety in healthy adults is poorly characterized.
Side Effects
- Hypoglycemia
- Joint pain
- Possible tissue overgrowth with chronic use
- Sodium retention
Related peptides
A GHRH analog designed for long-acting stimulation of natural growth hormone production.
A myostatin-binding protein studied for its potential to drive significant muscle hypertrophy by removing the body's natural growth ceiling.
A long-acting GLP-1 receptor agonist studied for its effects on appetite, satiety, and glucose regulation.