GHRP-2 vs IGF-1 LR3 vs Ipamorelin
A three-way comparison to help you find the right peptide for your research goals.
GHRP-2
Growth Hormone Releasing Peptide 2 (GHRP-2) is considered one of the most potent GHRPs available. It provides strong GH release with moderate hunger increase compared to GHRP-6.
Full details →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 →Side-by-Side Comparison
| Aspect | GHRP-2 | IGF-1 LR3 | Ipamorelin |
|---|---|---|---|
| Mechanism | Binds to the ghrelin receptor (GHS-R) to stimulate GH release from the pituitary. Also has some direct effects on the hypothalamus. Causes less appetite increase than GHRP-6. | 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. |
| Typical Dosage | Typical dosing: 100-300mcg administered 2-3 times daily. Often stacked with GHRH peptides for enhanced GH release. | 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. |
| Administration | Subcutaneous injection on an empty stomach. Can be used at bedtime to enhance natural GH pulse during sleep. | 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. |
| Side Effects | Moderate hunger increase, water retention, potential prolactin and cortisol elevation (less than GHRP-6), tingling sensations. | 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. |
| Best For |
What They Have in Common
GHRP-2, IGF-1 LR3, Ipamorelin are all commonly used for:
Key Differences
Unique to GHRP-2:
Unique to IGF-1 LR3:
Unique to Ipamorelin:
Detailed Analysis
Commonalities
Both GHRP-2 and IGF-1 LR3 are commonly used for Muscle Growth, Fat Loss.
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 GHRP-2 and Ipamorelin are commonly used for Muscle Growth, Fat Loss, Sleep Quality.
Which Should You Choose?
Ipamorelin has stronger evidence for Fat Loss, Sleep Quality.
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.