IGF-1 LR3 vs LL-37 (Cathelicidin)

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

IGF-1 LR3

IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.

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LL-37 (Cathelicidin)

LL-37 is the only human cathelicidin antimicrobial peptide. It plays crucial roles in innate immunity and has shown diverse biological activities including antimicrobial, immunomodulatory, and wound healing properties.

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Side-by-Side Comparison

AspectIGF-1 LR3LL-37 (Cathelicidin)
MechanismBinds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours.Disrupts bacterial membranes, neutralizes endotoxins, modulates immune cell function, and promotes wound healing. Has both direct antimicrobial and immunomodulatory effects.
Typical DosageResearch protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles.Research protocols vary widely. Typical ranges: 50-200mcg administered subcutaneously 2-3 times weekly. Some protocols use higher doses for acute infections.
AdministrationIntramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off.Subcutaneous injection. Can cause significant injection site reactions. Often used in conjunction with other immune-supporting protocols.
Side EffectsHypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions.Injection site pain and reactions are common. May cause flu-like symptoms, temporary fatigue, or immune activation responses.
Best For

What They Have in Common

Both IGF-1 LR3 and LL-37 (Cathelicidin) are commonly used for:

Key Differences

Unique to IGF-1 LR3:

Unique to LL-37 (Cathelicidin):

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