IGF-1 LR3
Written by Alejandro Reyes
Founder & Lead Researcher
Reviewed by Peptide Nerds Editorial · Updated April 2026
Key Takeaway
IGF-1 LR3 is a modified version of insulin-like growth factor 1 with a longer half-life, promoting muscle growth and recovery.
| Type | Growth Hormone |
| FDA Status | Research Only |
| Evidence Level | Moderate |
| Typical Dose | 20-50 mcg daily |
| Frequency | Once daily |
| Cycle Length | 4-6 weeks |
| Key Goals | muscle-growth |
How it works
Binds to IGF-1 receptors to promote protein synthesis, cell growth, and inhibit cell death. The LR3 modification extends half-life from minutes to 20-30 hours.
Benefits
- Enhanced muscle growth
- Improved recovery
- Cell proliferation
Side effects
- Hypoglycemia risk
- Joint pain
- Organ growth concerns with prolonged use
Dosing protocol
Typical Dose
20-50 mcg daily
Frequency
Once daily
Cycle Length
4-6 weeks
Use with caution. Monitor blood sugar.
Deeper on IGF-1 LR3
Full breakdowns of every part of the IGF-1 LR3 research base.
What you will need
Basic supplies for reconstitution and subcutaneous injection.
This page contains affiliate links. Learn more
Bacteriostatic Water (30mL)
$8-15Required for reconstituting lyophilized peptides. 30mL is standard.
Insulin Syringes (1mL, 29ga)
$12-20 (100ct)1mL insulin syringes with 29-gauge needles for subcutaneous injection.
Alcohol Prep Pads
$5-10 (200ct)Sterile 70% isopropyl alcohol wipes for injection site prep.
Sharps Container
$8-15FDA-cleared sharps disposal container for used needles.
Get the IGF-1 LR3 cheat sheet
Dosing quick-reference, key studies, and side effect management — in your inbox.
Get the IGF-1 LR3 cheat sheet
Dosing quick-reference, key studies, and side effect management — in your inbox.
Stacks with IGF-1 LR3
Related peptides
Looking for weight loss peptides? See our complete guide to the best peptides for weight loss or compare semaglutide vs tirzepatide .
Get the Peptide Starter Kit (free)
Quick-start guide to GLP-1 peptides, dosing basics, and what to ask your doctor.
Medical Disclaimer: This content is for informational and educational purposes only. It is not intended as medical advice or a substitute for professional medical consultation, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide protocol.