Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| IGF-1 LR3 | PEG-MGF | |
|---|---|---|
| Category | Growth Factors | Growth Factors |
| Standard Dose | Research indicates 20-50 mcg daily via subcutaneous or intramuscular injection. | — |
| Timing | Post-workout administration for muscle growth. Can be injected locally (intramuscularly) into target muscle groups. Morning dosing on rest days. | — |
| Cycle Duration | 4-6 week cycles maximum. Longer cycles risk significant side effects and receptor desensitization. | — |
| Evidence Level | moderate_human | Preclinical |
IGF-1 LR3 (Long Arginine 3-IGF-1) is an 83-amino acid synthetic analog of IGF-1 with an arginine substitution at position 3 and 13 additional N-terminal amino acids. These modifications eliminate binding to IGF-binding proteins, making it approximately 3x more potent than native IGF-1 with a half-life of 20-30 hours (vs 12-15 minutes for native IGF-1). It activates the IGF-1R tyrosine kinase receptor, triggering IRS-1/PI3K/Akt/mTOR and PI3K/Akt/GSK3-beta pathways to drive protein synthesis, muscle hypertrophy, and hyperplasia (new muscle cell formation).
Research indicates 20-50 mcg daily via subcutaneous or intramuscular injection.
Post-workout administration for muscle growth. Can be injected locally (intramuscularly) into target muscle groups. Morning dosing on rest days.
4-6 week cycles maximum. Longer cycles risk significant side effects and receptor desensitization.
Pegylated mechano growth factor analog discussed in muscle repair and hypertrophy contexts with limited human evidence.
Take our free assessment to get personalized recommendations based on your health goals, current stack, and biomarkers.
Get Your Free Protocol →or take the assessment →