Your body's own natural antibiotic peptide. It fights a wide range of bacteria, viruses, and fungi, helps break up bacterial biofilms (stubborn colonies that resist treatment), and supports wound healing while keeping your immune response in check.
What to Expect
Week 1–2
Enhanced innate antimicrobial defense. May notice faster resolution of minor infections. Improved wound healing speed.
Week 3–6
Biofilm disruption effects becoming apparent for chronic infections (Lyme, SIBO). Improved immune surveillance. Reduced chronic infection symptoms.
Week 8+
Sustained antimicrobial and immunomodulatory benefits. Chronic biofilm-associated infections may show significant improvement. Enhanced wound healing.
Common Side Effects
Scientific Overview
LL-37 is the only cathelicidin-derived antimicrobial peptide in humans, cleaved from the precursor protein hCAP18. This 37-residue, amphipathic α-helical peptide exhibits broad-spectrum antimicrobial activity against gram-positive/negative bacteria, fungi, and enveloped viruses through membrane disruption. Beyond direct antimicrobial activity, LL-37 modulates innate immunity by promoting chemotaxis of neutrophils and monocytes, stimulating angiogenesis, and modulating TLR signaling. It plays roles in wound healing, biofilm disruption, and immune surveillance.
Dosing
50-100 mcg subq daily, injected near the infection site. Cycle for 2-4 weeks.
Practical Guide
Reconstitution
Mix 5mg vial with 1-2mL BAC water. Typical dose is 50-100mcg.
Storage
Refrigerate after reconstitution. Use within 14-21 days. Sensitive to degradation.
Injection Sites
Subcutaneous with insulin syringe. Start with low dose and titrate up — Herxheimer reactions possible. Inject near infection site when possible.
Timing
Morning dosing preferred. May cause Herxheimer (die-off) reactions — start low and increase gradually.
Food
No food interactions.
Benefit Profile
Medical Considerations
Contraindications
- ✕Pregnancy/nursing
- ✕Active autoimmune conditions (psoriasis, rosacea — LL-37 is elevated in these conditions)
- ✕Sepsis risk
Drug Interactions
Recommended Monitoring
- →CBC with differential
- →CRP if treating infection
- →Monitor for Herxheimer reactions
This information is for educational purposes only. Always consult a qualified healthcare provider before starting any peptide protocol.
Published Research
LL-37 antimicrobial peptide: Molecular characterisation and its role in oral health and disease-A narrative review.
LL-37, the master antimicrobial peptide, its multifaceted role from combating infections to cancer immunity.
Cathelicidin LL-37 in periodontitis: current research advances and future prospects - A review.
Decoding LL-37: Structure and antimicrobial mechanisms against microbial threats.
Human antimicrobial/host defense peptide LL-37 may prevent the spread of a local infection through multiple mechanisms: an update.
Exploring the Antimicrobial Potential of LL-37 Derivatives: Recent Developments and Challenges.
Antimicrobial Peptides of the Cathelicidin Family: Focus on LL-37 and Its Modifications.
Cathelicidin expression in the pathogenesis of atopic dermatitis and the therapeutic potential of vitamin D.
Cathelicidin peptide LL-37: A multifunctional peptide involved in heart disease.
The LL-37 domain: A clue to cathelicidin immunomodulatory response?