Understand the source comparison
Long R3 IGF-1 Comparison: Native IGF-1, DES(1-3) IGF-1, and Receptor Selectivity
The table below compares Long R3 IGF-1 to native IGF-1 and DES(1-3) IGF-1. The three most commonly used IGF-1 analogs in biological research. Each peptide solves a different experimental constraint. Native IGF-1 70 ~10 minutes 100% (reference) Short-duration s
No winner is assigned.
This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- The table below compares Long R3 IGF-1 to native IGF-1 and DES(1-3) IGF-1. The three most commonly used IGF-1 analogs in biological research. Each peptide solves a different experimental constraint.
- Native IGF-1
- 70
- ~10 minutes
- 100% (reference)
- Short-duration signaling studies, serum-free cultures
- Requires frequent reapplication in serum-containing media; unsuitable for multi-day protocols without binding protein removal
- Long R3 IGF-1
- 83
- 20–30 hours
- 10–20% of native
- Multi-day cell culture, anabolic signaling studies, myogenesis and adipogenesis models
- Extended half-life is the key advantage; reduces experimental variance from peptide degradation; preferred for dose-response studies
- DES(1-3) IGF-1
- 67
- ~30 minutes
- ~10% of native
- Localized signaling studies, short-duration high-potency assays
- Truncated N-terminus increases receptor affinity but peptide degrades quickly; useful when maximal receptor activation over short intervals is required
- Long R3 IGF-1 occupies the middle ground between stability and potency. Native IGF-1 binds IGFBPs with the highest affinity, making it the least practical for serum-containing experiments. DES(1-3) IGF-1. Which lacks the first three amino acids. Shows reduced IGFBP binding and approximately 10× higher receptor affinity than native IGF-1, but its half-life remains short (under one hour in serum), limiting use to acute signaling studies. Long R3 IGF-1 sacrifices the hyper-potency of DES(1-3) in exchange for multi-day stability, making it the standard choice for differentiation protocols, proliferation assays, and metabolic studies requiring sustained receptor activation.
- In our experience supplying peptides to research labs, the most common error is selecting Long R3 IGF-1 for experiments where DES(1-3) would be more appropriate. Specifically, short-duration assays where maximal receptor activation is the goal. Long R3 IGF-1's advantage is duration, not peak signaling intensity. Conversely, using native IGF-1 in serum-containing cultures without accounting for IGFBP binding leads to irreproducible results. The effective free peptide concentration is unpredictable.