Compare Peptides

Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.

Popular comparisons

Lactoferrin

Lactotransferrin, LF

Unregulated
Immune & Antimicrobial

LL-37

Cathelicidin, Human Cathelicidin Antimicrobial Peptide

Unregulated
Immune & Antimicrobial
Overview

A naturally occurring iron-binding glycoprotein found in milk, saliva, tears, and mucosal secretions. One of the body's first-line innate immune defenses. Available as an oral supplement and in research-grade injectable form.

The only human cathelicidin antimicrobial peptide, LL-37 is a 37-amino-acid peptide naturally produced by immune cells, epithelial cells, and barrier tissues. It plays a critical role in innate immunity by directly killing bacteria, viruses, and fungi, while also modulating inflammatory responses. Increasingly studied for chronic infections, biofilm disruption, and immune regulation.

Mechanism of Action

Binds free iron, depriving bacteria of a nutrient essential for growth (bacteriostatic effect). Also directly disrupts bacterial cell membranes (bactericidal). Modulates immune response by promoting T-cell and NK cell activity while reducing inflammatory cytokines. Enhances iron absorption in the gut.

Disrupts microbial membranes through electrostatic interaction with negatively charged bacterial surfaces, creating pores that kill pathogens. Also modulates immune responses by recruiting immune cells, promoting wound healing, and disrupting bacterial biofilms. Acts as a bridge between innate and adaptive immunity.

Common Uses
  • Immune support
  • Iron deficiency (improves absorption)
  • Gut health
  • Antimicrobial defense
  • Anti-inflammatory support
  • Immune system support
  • Chronic infection management
  • Biofilm disruption (Lyme, SIBO)
  • Wound healing
  • Upper respiratory infection support
Known Risks
  • Generally well-tolerated orally
  • GI discomfort at high doses
  • Allergic reactions in dairy-sensitive individuals
  • Injectable form has limited safety data
  • Injection site reactions (pain, redness)
  • Potential autoimmune activation at high doses
  • Limited human clinical data for therapeutic use
  • Overexpression linked to psoriasis and rosacea in some contexts
Regulatory Status
Unregulated

Available as a dietary supplement (GRAS status). Not FDA-approved for any medical indication. Widely available OTC. Injectable form is research-only.

Unregulated

Not FDA-approved as a therapeutic. LL-37 is an endogenous human peptide being studied in clinical trials for wound healing and infection. Some compounding pharmacies have offered it, but it has no formal FDA category for compounding. Research is ongoing for topical wound applications.

This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.