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