GHRP-2 vs IGF-1 LR3 vs Sermorelin
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 →Sermorelin
Sermorelin is a synthetic analog of GHRH consisting of the first 29 amino acids of the natural hormone. It was previously FDA-approved for GH deficiency diagnosis and treatment in children.
Full details →Side-by-Side Comparison
| Aspect | GHRP-2 | IGF-1 LR3 | Sermorelin |
|---|---|---|---|
| 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. | Binds to GHRH receptors in the pituitary gland to stimulate natural GH production and release. Maintains the body's natural feedback mechanisms for GH regulation. |
| 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: 200-500mcg administered once daily, usually before bed. Some protocols use twice daily dosing. |
| 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, preferably at bedtime to work with natural GH release patterns. Can be combined with GHRPs for synergistic effects. |
| 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 injection site reactions, headache, flushing, or dizziness. Less side effects than direct GH administration. |
| Best For |
What They Have in Common
GHRP-2, IGF-1 LR3, Sermorelin are all commonly used for:
Key Differences
Unique to GHRP-2:
Unique to IGF-1 LR3:
Unique to Sermorelin:
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 Sermorelin are commonly used for Muscle Growth, Fat Loss, Sleep Quality.
Which Should You Choose?
GHRP-2 has stronger evidence for Muscle Growth.
Commonalities
Both IGF-1 LR3 and Sermorelin are commonly used for Muscle Growth, Fat Loss, Recovery & Healing.
Which Should You Choose?
IGF-1 LR3 has stronger evidence for Muscle Growth.