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IGF-1 LR3

Natty
muscle gainrecoverygrowth hormoneinjectablesubcutaneousintramuscular

What It Does

Powerfully increases muscle growth, protein synthesis, and fat burning. Accelerates tissue repair and recovery. Risk of hypoglycemia.

Natty Status Classification

This peptide is generally considered within the natty realm by some in the fitness community, particularly when used for therapeutic healing purposes. However, opinions vary, and competitive natural bodybuilding organizations may have different stances. Always check your federation's specific rules if you compete.

Description

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.

Full Description

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.

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.

What is Lyophilized Powder?

Lyophilized powder is a sterile, freeze-dried medication that must be reconstituted (mixed with a liquid solvent, like sterile water) before it can be injected. This process extends the drug's shelf life and stability, making it ideal for temperature-sensitive products. The lyophilization process removes water from the peptide in a frozen state through sublimation, which preserves the physical and chemical properties until it is needed.

Application Methods

  • Subcutaneous injection
  • Intramuscular injection

Product Names

  • IGF-1 LR3 Peptide
  • Long R3 Insulin-Like Growth Factor
  • IGF-1 Long Arg3

Benefits

  • Powerful muscle growth and hypertrophy stimulation
  • Enhanced protein synthesis and nitrogen retention
  • Accelerated tissue repair and regeneration
  • Improved fat metabolism and body composition
  • Faster recovery from training and injuries
  • Activation of muscle satellite cells for growth
  • Enhanced cellular proliferation and survival
  • Potential neuroprotective and cognitive benefits
  • Improved glucose uptake and metabolism
  • Reduced muscle breakdown and catabolism

Dosage Levels

  • 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
  • Intramuscular or subcutaneous injection
  • Cycle length: typically 4-6 weeks maximum
  • Often injected bilaterally into muscles being trained
  • Post-workout timing common due to enhanced nutrient uptake
  • 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

Research

Where to Buy

*Peptides are stored in form and need to be reconstituted with sterile bacteriostatic water before use.

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Last Updated: 10/19/2025