IGF-1 LR3 vs MOTS-c vs Sermorelin
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 →MOTS-c
MOTS-c (Mitochondrial Open Reading Frame of the Twelve S rRNA type-c) is a mitochondrial-derived peptide that plays a key role in metabolic regulation and has emerged as a significant longevity research target.
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 | IGF-1 LR3 | MOTS-c | Sermorelin |
|---|---|---|---|
| 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. | Activates AMPK pathway, enhances glucose uptake in skeletal muscle, improves insulin sensitivity, and regulates mitochondrial function. Acts as a metabolic hormone affecting whole-body energy homeostasis. | 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 | Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles. | Research protocols typically use 5-10mg administered subcutaneously several times per week. Optimal dosing not yet established. | Typical dosing: 200-500mcg administered once daily, usually before bed. Some protocols use twice daily dosing. |
| Administration | Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off. | Subcutaneous injection. Often combined with exercise protocols as it enhances exercise capacity and metabolic adaptation. | Subcutaneous injection, preferably at bedtime to work with natural GH release patterns. Can be combined with GHRPs for synergistic effects. |
| Side Effects | Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions. | Limited human data. Animal studies show good tolerability. May affect energy levels and exercise performance. | 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
IGF-1 LR3, MOTS-c, Sermorelin are all commonly used for:
Key Differences
Unique to IGF-1 LR3:
Unique to MOTS-c:
Unique to Sermorelin:
Detailed Analysis
Commonalities
Both IGF-1 LR3 and MOTS-c are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
IGF-1 LR3 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.
Commonalities
Both MOTS-c and Sermorelin 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.