Long R3 IGF-1 vs Insulin-like growth factor 1
IGF-1 re-engineered to slip past its binding proteins — more free signal, for longer. The hepatic mediator of growth hormone's anabolic effects. Side by side: type, evidence tier, receptor, molecular weight, and half-life — the same fields as each monograph, rearranged so the engineering difference is visible.
Long R3 IGF-1 IGF-1 LR3 | Insulin-like growth factor 1 IGF-1 | |
|---|---|---|
| Also known as | — | — |
| Type | Analog | Endogenous |
| Evidence | Preclinical | Established |
| Family | Growth & repair | Growth & repair |
| Class | 83-aa IGF-1 analog (Arg³ substitution + 13-aa N-terminal extension) | Single-chain growth factor (70 aa) |
| Receptor | IGF-1 receptor (IGF-1R), a receptor tyrosine kinase | IGF-1 receptor (IGF-1R, a receptor tyrosine kinase) |
| Molecular weight | ≈9,111 Da | ~7,649 Da |
| Half-life | Hours — free of the IGFBP clearance that limits native IGF-1 to ~10 min | |
| Based on | Insulin-like growth factor 1 | Native hormone |
Half-life bars are on a logarithmic scale across the molecules shown. Reference values for the native or representative form — educational only, not medical or dosing advice.
Common questions
- What is the difference between Long R3 IGF-1 and Insulin-like growth factor 1?
- Long R3 IGF-1 is an engineered analog based on Insulin-like growth factor 1; Insulin-like growth factor 1 is an endogenous hormone. Long R3 IGF-1 signals at IGF-1 receptor (IGF-1R), a receptor tyrosine kinase; Insulin-like growth factor 1 signals at IGF-1 receptor (IGF-1R, a receptor tyrosine kinase).
- How do the half-lives of IGF-1 LR3 and IGF-1 compare?
- The reported circulating half-life of Long R3 IGF-1 is Hours — free of the IGFBP clearance that limits native IGF-1 to ~10 min; Insulin-like growth factor 1 is ~12–16 h bound to IGFBPs (~10 min free). These are reference values for the native or representative form — educational only, not dosing advice.
Prefer the other order? Insulin-like growth factor 1 vs Long R3 IGF-1. Or open the interactive comparison tool to add more molecules.