Source comparison
IGF-1 LR3 Benefits: Research Application Comparison
The following table compares IGF-1 LR3 to native IGF-1 and other growth factor analogs across key research parameters. These distinctions determine experimental design, dosing frequency, and data interpretation. Half-life ~10 minutes 20–30 hours ~15 minutes ~2
This comparison does not assign a generated winner or score.
- The following table compares IGF-1 LR3 to native IGF-1 and other growth factor analogs across key research parameters. These distinctions determine experimental design, dosing frequency, and data interpretation.
- Half-life
- ~10 minutes
- 20–30 hours
- ~15 minutes
- ~20 minutes
- IGF-1 LR3's extended half-life eliminates the need for continuous infusion in vivo, making it the most practical analog for multi-day studies requiring sustained exposure.
- IGFBP Binding Affinity
- High (~100% bound)
- Low (~1% bound)
- Moderate (~80% bound)
- Very Low (~0.1% bound)
- Both LR3 and DES evade IGFBPs, but DES's ultra-short half-life limits its use to acute signaling studies or localized delivery models.
- Receptor Selectivity
- IGF-1R >> Insulin R
- IGF-2R ≥ IGF-1R
- All analogs show IGF-1R preference except IGF-2, which signals through a distinct receptor lacking intrinsic kinase activity. Different mechanism entirely.
- In Vitro Potency (EC50)
- 1–5 nM
- 0.5–2 nM
- 5–10 nM
- 0.1–0.5 nM
- DES is most potent per-mole in cell culture, but LR3 produces equivalent or greater effect at 24-hour timepoints due to stability.
- Systemic Bioavailability
- Very Low (IGFBP sequestration)
- High (free circulation)
- Low (IGFBP + rapid clearance)
- High (free circulation, short duration)
- For in vivo systemic studies, LR3 is the only analog that delivers consistent plasma exposure without infusion pumps.
- This table underscores the tradeoff between potency and duration. DES(1-3) IGF-1. Which lacks the first three N-terminal amino acids. Exhibits the highest per-molecule potency but requires dosing every 4–6 hours in vivo to maintain receptor activation. IGF-1 LR3 benefits include a pharmacokinetic profile that matches the timescale of most phenotypic endpoints (muscle fiber cross-sectional area, glucose uptake, lipogenesis) without the confounding variable of fluctuating hormone levels.