IGF-1 LR3 vs Sermorelin vs Tesamorelin
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 →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 →Tesamorelin
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH). It is FDA-approved under the brand name Egrifta for reducing excess abdominal fat in HIV-infected patients with lipodystrophy.
Full details →Side-by-Side Comparison
| Aspect | IGF-1 LR3 | Sermorelin | Tesamorelin |
|---|---|---|---|
| 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. | 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. | Stimulates the pituitary gland to produce and release growth hormone by binding to GHRH receptors. Increases IGF-1 levels which promotes lipolysis and reduces visceral adipose tissue. |
| Typical Dosage | 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. | FDA-approved dose: 2mg administered subcutaneously once daily. Research protocols may use various dosing schedules. |
| Administration | 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. | Subcutaneous injection into the abdomen. Rotate injection sites. Best administered at the same time daily, preferably in the evening. |
| Side Effects | 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. | Common side effects include injection site reactions (erythema, pruritus), joint pain, peripheral edema, and muscle pain. May cause elevated blood glucose. |
| Best For |
What They Have in Common
IGF-1 LR3, Sermorelin, Tesamorelin are all commonly used for:
Key Differences
Unique to IGF-1 LR3:
Unique to Sermorelin:
Detailed Analysis
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 IGF-1 LR3 and Tesamorelin are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
IGF-1 LR3 has stronger evidence for Muscle Growth. Tesamorelin has stronger evidence for Fat Loss.
Commonalities
Both Sermorelin and Tesamorelin are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
Tesamorelin has stronger evidence for Fat Loss.