IGF-1 LR3 (also known as IGF-1 LR3 or Long R3 IGF-1 or Long Arg3 IGF-1) is a therapeutically researched peptide studied for its effects on muscle gain, recovery, growth hormone. Synthetic long-acting IGF-1 analog with 3x potency and 20-30 hour half-life. Promotes muscle growth, tissue repair, and fat metabolism. Not FDA-approved, significant risks.
IGF-1 LR3 (Long Arg3 Insulin-Like Growth Factor-1) is a synthetic 83-amino acid analog of human insulin-like growth factor-1 (IGF-1), engineered with an arginine substitution at position 3 and an additional 13 amino acids at the N-terminus. These structural modifications significantly reduce its binding affinity to IGF-binding proteins (IGFBPs), resulting in an extended half-life of approximately 20-30 hours (compared to native IGF-1's ~10 minutes) and roughly three times greater biological potency than endogenous IGF-1. The peptide functions by binding to IGF-1 receptors (IGF-1R) on various cell types, initiating complex intracellular signaling cascades through the PI3K/Akt and MAPK/ERK pathways that promote cellular proliferation, differentiation, protein synthesis, and cell survival while inhibiting apoptosis.
Overview
IGF-1 LR3 has been extensively studied in preclinical research for its powerful anabolic effects, including stimulation of muscle hypertrophy through satellite cell activation, enhanced nitrogen retention and protein synthesis, accelerated tissue repair and regeneration, improved fat metabolism and lean mass development, potential neuroprotective effects through neurogenesis and synaptic plasticity, and metabolic benefits through enhanced glucose uptake in muscle and adipose tissue.
Due to its structural similarity to insulin, it also demonstrates some insulin-like metabolic effects.
However, IGF-1 LR3 carries significant risks including hypoglycemia (especially with continuous high dosing), potential increased cancer risk due to cellular proliferation effects, muscle and joint pain, and other side effects.
It is not FDA-approved for therapeutic use, is classified as a prohibited substance by the World Anti-Doping Agency (WADA), and remains strictly designated for research purposes only.
The compound requires careful handling, proper reconstitution with bacteriostatic water, and refrigerated storage.
Mechanism of action
Powerfully increases muscle growth, protein synthesis, and fat burning. Accelerates tissue repair and recovery. Risk of hypoglycemia.
Dosage and administration
Research Beginner
- 20-40mcg daily, typically post-workout
Research Intermediate
- 40-60mcg daily, split into 1-2 doses
Research Advanced
- 60-100mcg daily, split into 2 doses
General
- Intramuscular or subcutaneous injection
- Often injected bilaterally into muscles being trained
- Minimum 4-6 week break between cycles recommended
- Reconstitute with bacteriostatic water or acetic acid
- Store reconstituted solution at 2-8°C, use within 14-30 days
Cycle length
- typically 4-6 weeks maximum
Post
- workout timing common due to enhanced nutrient uptake
Natty status
IGF-1 LR3 is generally regarded as compatible with the natty designation, particularly when used for therapeutic healing purposes. Opinions vary across natural bodybuilding federations, and athletes who compete should consult the rulebook of their respective sanctioning body.[1]
Research
No primary research references are catalogued for this compound on Retapedia.
Related compounds
Other peptides in this catalogue with overlapping mechanisms or status:
References
External links
- 1mg IGF-1 LR3 — commercial
- Bacteriostatic Water Reconstitution Solution 10ml — commercial
This page was last edited on May 25, 2026, at 01:15 (UTC).
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