Growth Factors

IGF-1 LR3

Evidence: moderate_human

Mechanism of Action

IGF-1 LR3 (Long Arginine 3-IGF-1) is an 83-amino acid synthetic analog of IGF-1 with an arginine substitution at position 3 and 13 additional N-terminal amino acids. These modifications eliminate binding to IGF-binding proteins, making it approximately 3x more potent than native IGF-1 with a half-life of 20-30 hours (vs 12-15 minutes for native IGF-1). It activates the IGF-1R tyrosine kinase receptor, triggering IRS-1/PI3K/Akt/mTOR and PI3K/Akt/GSK3-beta pathways to drive protein synthesis, muscle hypertrophy, and hyperplasia (new muscle cell formation).

Dosing Protocol

Standard: Research indicates 20-50 mcg daily via subcutaneous or intramuscular injection.

Maintenance: Research indicates 20 mcg daily or bilaterally at injection sites.

Administration: subcutaneousintramuscular

Timing: Post-workout administration for muscle growth. Can be injected locally (intramuscularly) into target muscle groups. Morning dosing on rest days.

Duration: 4-6 week cycles maximum. Longer cycles risk significant side effects and receptor desensitization.

Notes

IGF-1 LR3 is among the highest-risk peptides in this database. The hypoglycemia risk is real and potentially fatal — clients must always have fast-acting glucose available. Chronic use can cause organ growth (intestines, heart) similar to acromegaly. The cancer risk with elevated IGF-1 is well-documented in epidemiological studies. IGF-1 LR3 promotes both hypertrophy (cell growth) AND hyperplasia (new cell formation) — a distinction from most other anabolic compounds. Reserved for advanced, well-monitored clients only. Not recommended as a first-line intervention.

Stacking

  • HGH
  • MGF
  • PEG-MGF

Interactions

  • Insulin [HIGH] — IGF-1 LR3 causes significant hypoglycemia risk; extreme caution with insulin co-administration.
  • HGH [MEDIUM] — HGH increases endogenous IGF-1; combined with exogenous IGF-1 LR3, total IGF-1 activity may be excessive.
  • Oral hypoglycemics [HIGH] — Additive hypoglycemia risk.

Contraindications

  • Active cancer or history of cancer (IGF-1 is a potent growth factor for tumors)
  • Diabetic retinopathy
  • Pregnancy and breastfeeding
  • Acromegaly features
  • Under 25 years of age (growth plate concerns)

Side Effects

  • Hypoglycemia (primary danger — can be severe)
  • Organ and intestinal growth with chronic use
  • Joint pain
  • Jaw/hand growth (prolonged use)
  • Increased tumor risk
  • Water retention
  • Neuropathy

Key Papers

  • 10.1210/er.2009-0010
  • 10.3390/ijms21030713

Source Quality

Research-grade supplier with rigorous third-party testing. Counterfeits common. Verify via HPLC and mass spectrometry COA.

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Disclaimer: This information is for educational purposes only and is not medical advice. BioAccelera Labs does not diagnose, treat, or prescribe. Consult a licensed healthcare provider before using any compound.

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