IGF-1 LR3 vs Ipamorelin vs PEG-MGF
A three-way comparison to help you find the right peptide for your research goals.
IGF-1 LR3
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.
Full details →Ipamorelin
Ipamorelin is a selective growth hormone secretagogue that stimulates the release of growth hormone from the pituitary gland without significantly affecting cortisol or prolactin.
Full details →PEG-MGF
PEG-MGF (PEGylated Mechano Growth Factor) is a variant of IGF-1 that is produced in response to muscle damage. PEGylation extends its half-life from minutes to several hours, making it practical for use.
Full details →Side-by-Side Comparison
| Aspect | IGF-1 LR3 | Ipamorelin | PEG-MGF |
|---|---|---|---|
| Mechanism | Binds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours. | Acts as a ghrelin mimetic, binding to the ghrelin receptor (GHS-R) in the pituitary to stimulate GH release. Highly selective with minimal effect on other hormones. | Activates muscle satellite cells (stem cells) and promotes their fusion to existing muscle fibers for repair and growth. MGF is produced naturally in response to mechanical stress on muscles. |
| Typical Dosage | Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles. | Typical dosing ranges from 200-300mcg administered 2-3 times daily, often combined with CJC-1295. | Research protocols typically use 200-400mcg injected into targeted muscle groups 2-3 times weekly, usually post-workout. |
| Administration | Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off. | Subcutaneous injection. Best results when administered fasted or before sleep. Often stacked with GHRH peptides. | Intramuscular injection, ideally into muscles trained that day. Best administered post-workout when satellite cell activation is relevant. |
| Side Effects | Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions. | Generally well-tolerated. May cause mild headaches, lightheadedness, or increased hunger initially. | Injection site soreness, potential hypoglycemia, and localized swelling. Generally well-tolerated. |
| Best For |
What They Have in Common
IGF-1 LR3, Ipamorelin, PEG-MGF are all commonly used for:
Key Differences
Unique to IGF-1 LR3:
Unique to Ipamorelin:
Detailed Analysis
Commonalities
Both IGF-1 LR3 and Ipamorelin are commonly used for Muscle Growth, Fat Loss, Recovery & Healing.
Which Should You Choose?
Ipamorelin has stronger evidence for Fat Loss.
Commonalities
Both IGF-1 LR3 and PEG-MGF are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
IGF-1 LR3 has stronger evidence for Muscle Growth.
Commonalities
Both Ipamorelin and PEG-MGF are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
Ipamorelin has stronger evidence for Muscle Growth.