LL-37 (Cathelicidin) vs MK-677 (Ibutamoren)

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

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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MK-677 (Ibutamoren)

MK-677, also known as Ibutamoren, is an orally active growth hormone secretagogue. Unlike peptides, it can be taken orally and has a long half-life, providing 24-hour GH elevation.

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Side-by-Side Comparison

AspectLL-37 (Cathelicidin)MK-677 (Ibutamoren)
MechanismDisrupts bacterial membranes, neutralizes endotoxins, modulates immune cell function, and promotes wound healing. Has both direct antimicrobial and immunomodulatory effects.Acts as a potent, selective agonist of the ghrelin receptor (GHS-R1a). Increases GH and IGF-1 levels without affecting cortisol. Mimics ghrelin's GH-releasing effects.
Typical DosageResearch protocols vary widely. Typical ranges: 50-200mcg administered subcutaneously 2-3 times weekly. Some protocols use higher doses for acute infections.Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase.
AdministrationSubcutaneous injection. Can cause significant injection site reactions. Often used in conjunction with other immune-supporting protocols.Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing.
Side EffectsInjection site pain and reactions are common. May cause flu-like symptoms, temporary fatigue, or immune activation responses.Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity.
Best For

What They Have in Common

Both LL-37 (Cathelicidin) and MK-677 (Ibutamoren) are commonly used for:

Key Differences

Unique to LL-37 (Cathelicidin):

Unique to MK-677 (Ibutamoren):

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