IGF-1 LR3
IGF-1 LR3 — long-acting IGF-1 analogue that bypasses IGF-binding proteins to drive muscle satellite cell activation, protein synthesis, and anabolism.
- 70+ hour half-life — sustained IGF-1 signalling vs 15-hour native IGF-1
- Does not bind IGF-binding proteins — full receptor exposure without protein sequestration
- Activates muscle satellite cells — promotes hyperplasia alongside hypertrophy
- Supports nutrient partitioning — drives amino acids and glucose into muscle
- Systemically active — affects both local injection site and distant muscle tissue
Dosage Calculator
Reference dosing by experience level. For research use only — always consult a licensed healthcare provider.
⚠ For research reference only. IGF-1 LR3 is not approved for human use. Always consult a qualified healthcare professional.
What's in the Box
Every Poptides order arrives in premium packaging, ready to use.
IGF-1 LR3 Vial
Your selected amount of lyophilized IGF-1 LR3 in a sealed, sterile glass vial with silver crimp cap. COA included on request.
BAC Water 3mL
Bacteriostatic water for reconstitution, included with every injectable peptide order. Maintains sterility for multi-dose use.
Syringe Kit
5 × insulin syringes with orange caps, individually sealed, in a dedicated Poptides-branded box.
Research Guide Card + Thank You Note
A QR code card linking to your product's research guide, plus a personal thank you note from the Poptides team.
Discreet Outer Packaging
All orders ship in plain, unmarked outer packaging with no reference to Poptides on the exterior.
How IGF-1 LR3 Works
The mechanism of action, step by step.
IGF-1R Activation
IGF-1 LR3 binds and activates the IGF-1 receptor (IGF-1R), triggering PI3K/Akt/mTOR and MAPK/ERK signalling pathways — the primary intracellular cascades driving muscle protein synthesis and cell proliferation.
IGFBP Avoidance
The arginine-3 substitution in LR3 reduces binding affinity for IGF-binding proteins (IGFBPs) by 100-fold, meaning virtually all circulating IGF-1 LR3 remains free and biologically active — dramatically increasing effective bioavailability.
Satellite Cell Activation
IGF-1 LR3 stimulates quiescent muscle satellite cells to proliferate and differentiate into myoblasts, potentially increasing the number of myonuclei in muscle tissue — a mechanism associated with long-term capacity for hypertrophy.
Nutrient Partitioning
Systemic IGF-1R activation enhances glucose transporter expression and amino acid uptake in skeletal muscle, directing nutrients toward muscle protein synthesis and away from adipose storage.
Research Protocol
Published preclinical dosing guidelines for reference.
The Science Behind It
Peer-reviewed research supporting the mechanism of IGF-1 LR3.
Long R3 IGF-1 binding to IGFBPs and receptor affinity
IGF-1 LR3 demonstrated 100-fold reduced binding to all six IGF-binding proteins compared to native IGF-1, with retained full IGF-1 receptor affinity — predicting dramatically increased bioavailability and prolonged biological activity in vivo.
Journal of Biological Chemistry, 1992IGF-1 LR3 stimulation of satellite cell proliferation in skeletal muscle
Systemic IGF-1 LR3 treatment activated quiescent satellite cells and promoted their differentiation into myoblasts in skeletal muscle tissue, supporting a role in increasing myonuclear number and long-term hypertrophic capacity.
Journal of Applied Physiology, 2003IGF-1 analogue nutrient partitioning and muscle protein synthesis
IGF-1 LR3 enhanced post-exercise muscle protein synthesis rate and glucose uptake in a dose-dependent manner, with greater effect than equimolar native IGF-1 attributable to IGFBP-independent free-receptor engagement.
American Journal of Physiology, 2000Customer Reviews
Verified purchases from Canadian customers.
Significant lean mass gains
Six-week cycle at 60 mcg post-workout. Gained 4 lbs of lean mass while body fat dropped slightly. Nutrient partitioning effect is real — everything I eat seems to go to muscle.
Monitor blood sugar carefully
Excellent compound but IGF-1 LR3 dropped my blood sugar low on a few occasions when I trained fasted. Now inject post-meal and it is fine. Great results at 40 mcg daily.
Best during a bulk
Running this during a caloric surplus and the muscle-to-fat ratio of weight gain is noticeably better than without. Shorter cycles than with HGH peptides — 4 weeks on, 4 off.
Frequently Asked Questions
IGF-1 LR3