IGF-1 LR3
Also known as: Insulin-like Growth Factor 1 Long R3
Overview
IGF-1 LR3 is a modified analogue of Insulin-like Growth Factor 1 with an extended half-life due to reduced binding affinity for IGF binding proteins. It promotes muscle cell proliferation and differentiation, and is one of the most potent anabolic peptides available. Requires careful dosing due to hypoglycaemia risk.
How it works
Binds to IGF-1 receptors on muscle cells, activating the PI3K-Akt-mTOR signalling pathway which drives protein synthesis, cell proliferation, and inhibits apoptosis. Promotes satellite cell activation and muscle hypertrophy. Also stimulates glucose uptake in muscle tissue which can cause hypoglycaemia if doses are too high.
Primary uses
- Muscle cell proliferation
- Hypertrophy
- Recovery acceleration
- Fat metabolism
- Anti-catabolic effects
What to expect
Based on reported user experiences and available research, here is a general timeline of effects:
Days 1–7
- PI3K-Akt-mTOR signalling activates immediately — muscle protein synthesis is elevated
- Monitor blood glucose — hypoglycaemia risk is highest in the first week
- Post-workout administration maximises muscle cell uptake
Days 7–28
- Satellite cell activation and muscle hypertrophy are progressing
- Recovery between sessions is typically significantly faster
- Fat metabolism improvements are active alongside muscle growth
Days 28–84
- Significant hypertrophy and strength gains expected at 4-8 weeks
- Anti-catabolic effects are well established
- Consider a rest period after 4-6 weeks to prevent receptor desensitisation
Days 84–999
- Extended use beyond 8-10 weeks requires careful monitoring
- Consider cycling off to restore receptor sensitivity
- Long-term use data is limited — exercise caution and monitor with blood work
Storage and preparation
Store lyophilised at -20°C. Once reconstituted, store at 4°C and use within 14 days. Very sensitive to degradation — handle carefully and minimise freeze-thaw cycles.
Reconstitute with acidified water (0.1% acetic acid) or bacteriostatic water. Common: 1mg vial with 2ml gives 500mcg/ml. For 50mcg dose, draw 0.1ml. Administer post-workout for optimal uptake.
Research
The following studies are available via PubMed:
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