IGF-1 LR3 vs MGF (Mechano Growth Factor)
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 →MGF (Mechano Growth Factor)
MGF (Mechano Growth Factor) is a splice variant of IGF-1 that is produced locally in muscle tissue in response to mechanical stress. The non-PEGylated form has a very short half-life.
Full details →Side-by-Side Comparison
| Aspect | IGF-1 LR3 | MGF (Mechano Growth Factor) |
|---|---|---|
| Dose Range | 20 mcg–100 mcg | 400 mcg–1.2 mg |
| Frequency | 1x daily | Less than daily |
| Cycle Length | 4–6 weeks | 4–6 weeks |
| Route | subcutaneous | intramuscular |
| 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 muscle satellite cells (stem cells) and promotes their proliferation without differentiation, priming them for fusion with existing muscle fibers during repair and growth. |
| Typical Dosage | Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles. | Due to extremely short half-life (minutes), typical protocols use 100-200mcg injected directly into target muscles immediately post-workout. |
| Administration | Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off. | Intramuscular injection into trained muscles within minutes of workout completion. Must be used immediately after reconstitution due to instability. |
| Side Effects | Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions. | Injection site soreness, potential hypoglycemia, localized swelling. Short half-life limits systemic effects. |
| Best For |
What They Have in Common
IGF-1 LR3, MGF (Mechano Growth Factor) are both commonly used for:
Key Differences
Unique to IGF-1 LR3:
Which Has Stronger Evidence?
- Muscle Growth: IGF-1 LR3 has stronger research support.
| Goal | IGF-1 LR3 | MGF (Mechano Growth Factor) |
|---|---|---|
| Muscle Growth | high | medium |
| Recovery & Healing | medium | medium |
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
MGF (Mechano Growth Factor)
- The role of mechano growth factor in chondrocytes and cartilage defects: a concise review.
Acta biochimica et biophysica Sinica, 2023
- Pretreatment with mechano growth factor E peptide attenuates osteoarthritis through improving cell proliferation and extracellular matrix synthesis in chondrocytes under severe hypoxia.
International immunopharmacology, 2021
- Mechano growth factor interacts with nucleolin to protect against cisplatin-induced neurotoxicity.
Experimental neurology, 2020
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