IGF-1 LR3
Long Arginine 3-IGF-1
Three times more potent than native IGF-1
IGF-1 LR3 is a modified version of insulin-like growth factor 1 with enhanced potency and longer half-life. Used in muscle-building and anti-aging research.
Admin routes
Subcutaneous, Intramuscular
Popularity
Medium
Side effects
Monitor closely
AU vendors
0 rated
✓Key benefits
📈What to expect
Enhanced muscle pump during exercise; improved recovery
Increased muscle fullness and vascularity
Measurable strength and lean mass gains
Full protocol benefits; cycle off to prevent desensitisation
Based on community reports and published research. Individual results vary significantly.
💊Dosing protocols
Muscle growth
20–50 mcg
Once daily
4–8 weeks
Recovery
50–100 mcg
Once daily
4–6 weeks
Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.
Research status|Extensive preclinical data - used in research since the 1990s
Overview
IGF-1 LR3 is a synthetic analog of insulin-like growth factor 1 (IGF-1) with an arginine substitution at position 3 and a 13-amino-acid extension at the N-terminus. These modifications reduce binding to IGF binding proteins, resulting in approximately three times greater potency than native IGF-1 and a half-life of 20–30 hours compared to minutes for natural IGF-1.
⚙️How it works
Activates IGF-1 receptors through two primary pathways: the PI3K-AKT pathway (promoting glucose uptake, protein synthesis, and muscle growth) and the RAS-RAF-MAPK pathway (stimulating cell proliferation and tissue regeneration). Its structural modifications make it more bioavailable and longer-lasting in circulation than native IGF-1.
⚡Side effects
📅Research history
IGF-1 first produced by recombinant DNA technology
LR3 variant developed with reduced IGFBP binding
Widely adopted in bodybuilding community
WADA intensifies testing for IGF-1 variants
Research focus shifts to anti-aging and recovery applications
IGF-1 LR3 vs native IGF-1
Native IGF-1 has a half-life of only 12–15 minutes in circulation because 95% is bound to IGF binding proteins (IGFBPs). LR3's structural modifications dramatically reduce IGFBP binding, meaning more free IGF-1 is available to activate receptors. This makes it far more potent per microgram but also requires careful dosing - the extended activity window means effects (including side effects) last longer.
Reconstitution and storage
IGF-1 LR3 typically comes in 1 mg vials. Reconstitute with 1 mL of bacteriostatic water for 1000 mcg/mL. At 50 mcg per dose, this gives 20 doses per vial. Use a 100-unit insulin syringe - 50 mcg = 5 units. Store reconstituted at 2–8°C, use within 3 weeks.
References
- [1]Francis GL, et al. 'Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I.' Journal of Molecular Endocrinology, 1992.
- [2]Tomas FM, et al. 'Superior potency of infused IGF-I analogues which bind poorly to IGF-binding proteins.' American Journal of Physiology, 1993.
Frequently asked questions
Related peptides
Community experiences
Share your experience with IGF-1 LR3. Effects, side effects, protocol details - help others make informed decisions.
No community reviews yet. Be the first to share your experience with IGF-1 LR3.
Need to calculate your dose?
Use our free reconstitution calculator to work out syringe units for IGF-1 LR3.
Open CalculatorDisclaimer: This guide is for educational and informational purposes only. It is not medical advice. The dosing protocols listed are sourced from published research and community reports and do not constitute a recommendation. Always consult a qualified healthcare professional before using any peptide. Australian regulations classify many peptides as Schedule 4 (prescription-only) substances. Check current TGA guidelines before purchasing.