IGF-1 LR3 vs Selank
A detailed comparison to help you understand the differences and choose 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 →Selank
Selank is a synthetic peptide derived from the naturally occurring immunomodulatory peptide tuftsin. Developed in Russia for anxiety and cognitive enhancement.
Full details →Side-by-Side Comparison
| Aspect | IGF-1 LR3 | Selank |
|---|---|---|
| Dose Range | 20 mcg–100 mcg | 300 mcg–900 mcg |
| Frequency | 1x daily | 2x daily |
| Cycle Length | 4–6 weeks | 2–4 weeks |
| Route | subcutaneous | intranasal |
| 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. | Modulates the expression of brain-derived neurotrophic factor (BDNF) and affects serotonin and norepinephrine systems. Has immunomodulatory and anxiolytic properties. |
| Typical Dosage | Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles. | Intranasal administration: 250-500mcg 2-3 times daily. Subcutaneous: 250-500mcg daily. |
| Administration | Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off. | Most commonly administered intranasally for cognitive effects. Can also be injected subcutaneously. |
| Side Effects | Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions. | Generally well-tolerated. Some users report mild fatigue or nasal irritation with intranasal use. |
| Best For |
Key Differences
Unique to IGF-1 LR3:
Unique to Selank:
Key Studies
IGF-1 LR3
- IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep.
American journal of physiology. Endocrinology and metabolism, 2025
- Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regeneration.
International journal of biological macromolecules, 2025
- Attenuated glucose-stimulated insulin secretion during an acute IGF-1 LR3 infusion into fetal sheep does not persist in isolated islets.
Journal of developmental origins of health and disease, 2023
Selank
- Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats.
Bulletin of experimental biology and medicine, 2022
- The Influence of Selank on the Level of Cytokines Under the Conditions of "Social" Stress.
Current reviews in clinical and experimental pharmacology, 2021
- Functional Connectomic Approach to Studying Selank and Semax Effects.
Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 2020
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