IGF-1 LR3 vs Ipamorelin vs Mod GRF 1-29
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 →Mod GRF 1-29
Mod GRF 1-29 (Modified GRF 1-29, also called CJC-1295 without DAC or Tetrasubstituted GRF 1-29) is a modified growth hormone-releasing hormone analog with improved stability over natural GHRH.
Full details →Side-by-Side Comparison
| Aspect | IGF-1 LR3 | Ipamorelin | Mod GRF 1-29 |
|---|---|---|---|
| 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. | Binds to GHRH receptors in the pituitary gland to stimulate growth hormone release. Four amino acid substitutions improve resistance to enzymatic degradation while maintaining biological activity. |
| 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. | Typical dosing: 100-300mcg administered 2-3 times daily, usually combined with a GHRP like Ipamorelin for synergistic effects. |
| 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. | Subcutaneous injection. Best administered on empty stomach. Short half-life (~30 minutes) necessitates multiple daily doses, unlike DAC version. |
| 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. | Flushing, headache, dizziness, and injection site reactions. Generally well-tolerated. May cause water retention. |
| Best For |
What They Have in Common
IGF-1 LR3, Ipamorelin, Mod GRF 1-29 are all commonly used for:
Key Differences
Unique to Ipamorelin:
Unique to Mod GRF 1-29:
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 Mod GRF 1-29 are commonly used for Muscle Growth, Fat Loss, Recovery & Healing.
Which Should You Choose?
Both peptides have similar evidence levels for their shared goals. Your choice may depend on specific use case, availability, or personal response.
Commonalities
Both Ipamorelin and Mod GRF 1-29 are commonly used for Muscle Growth, Fat Loss, Recovery & Healing, Sleep Quality.
Which Should You Choose?
Ipamorelin has stronger evidence for Fat Loss, Sleep Quality.