IGF-1 LR3

Also known as: Long R3 IGF-1, LR3-IGF-1

A modified IGF-1 with extended half-life and enhanced potency.

Overview

IGF-1 LR3 is a modified form of insulin-like growth factor-1 with an arginine substitution at position 3 and a 13 amino acid extension. These modifications reduce IGF binding protein affinity, increasing bioactivity.

Mechanism of Action

Activates IGF-1 receptors with higher potency than native IGF-1 due to reduced IGFBP sequestration. Promotes protein synthesis, cellular proliferation, and inhibits apoptosis.

Pharmacokinetics

Extended half-life (~20-30 hours) compared to native IGF-1 (~15 minutes). Greater tissue exposure and bioactivity.

Dosing Protocols

Note: These are research protocols from literature. This is not medical advice.

1

Research

Dose

20-50 mcg

Frequency

Once daily

Duration

4-6 weeks

Post-workout or morning; monitor glucose

Stacking Recommendations

Peptides that may be combined based on complementary mechanisms in research settings.

Rationale: Muscle growth

Synergy: Satellite cell activation plus systemic IGF

Rationale: Complete GH/IGF axis

Synergy: Endogenous plus exogenous IGF effects

Research Areas

Muscle GrowthTissue RepairMetabolic ResearchCell Culture

Key Research Findings

  • 12-3x more potent than native IGF-1 in cell proliferation
  • 2Significantly longer half-life than native IGF-1
  • 3Widely used in cell culture and research
  • 4Anabolic effects on skeletal muscle

Side Effects & Contraindications

Reported Side Effects

  • Hypoglycemia
  • Joint pain
  • Water retention

Contraindications

  • Active malignancy
  • Diabetes
  • Pregnancy

Safety Considerations

Hypoglycemia risk. Theoretical cancer concerns due to mitogenic effects. Requires careful dosing.

Storage Requirements

Store lyophilized at -20C. Very temperature sensitive.

Scientific References

Quick Reference

Sequence
MFPAMPLSSL(13 AA extension)-GPETR3LCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA
Molecular Weight
9111 g/mol
Half-Life
20-30 hours
Bioavailability
High (SC, IM)
Research Stage
preclinical
Administration
Subcutaneous or intramuscular