LL-37 (Human Cathelicidin)
Human Cathelicidin | Antimicrobial Peptide
Community Research
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LL-37 is the only human cathelicidin antimicrobial peptide, a 37-amino acid cationic peptide derived from hCAP18 that exhibits broad-spectrum antimicrobial activity against bacteria, viruses, and fungi while modulating immune responses.
Provides direct antimicrobial activity through membrane disruption, promotes wound healing by enhancing keratinocyte migration and angiogenesis, and modulates immune responses without systemic exposure when used topically.
Molecular Data
Research Indications
68% ulcer area reduction demonstrated with 0.5mg/mL concentration in clinical trials.
Enhanced granulation tissue formation and wound closure.
Accelerated healing demonstrated in animal models.
Boosts natural immune defenses against pathogens.
Active against MRSA and multi-drug resistant bacteria with >4 log reduction in biofilms.
Balances immune responses without causing immunosuppression.
Stimulates skin cell growth and regeneration.
Promotes new blood vessel formation for tissue repair.
Supports collagen production for wound healing.
Dosing Protocols
Topical application is the most established route, providing direct access to wound sites with minimal systemic exposure.
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Wound healing - Standard | 0.5mg/mL gel/cream | Daily to twice weekly | Direct wound application |
| Wound healing - Intensive | 1.6mg/mL gel/cream | Daily | Direct wound application |
Reconstitution Instructions
- 1 Clean and debride wound area
- 2 Apply thin layer directly to wound surface
- 3 Cover with sterile dressing if needed
- 4 Change per clinical protocol (daily to twice weekly)
- 5 Monitor healing progress and adjust frequency
- 6 Document wound measurements and progression
Interactions
What to Expect
Side Effects & Safety
Common Side Effects
- Generally well-tolerated
- Mild injection site reactions (injectable)
- Local irritation at application site (topical)
Stop Signs - Discontinue if:
- Severe injection site reactions with spreading inflammation
- Allergic reaction signs (rash, difficulty breathing, swelling)
- Persistent flu-like symptoms
- Signs of wound infection (increased redness, warmth, drainage)
- Worsening wound condition or delayed healing
- Unusual pain or irritation at application site
Contraindications
- Pre-existing hypersensitivity to peptides
- Compromised immune status (relative contraindication)
- Non-sterile wound environments
Quality Checklist
Good Signs
- Sterile, clear formulation
- ≥98% purity by HPLC
- White to off-white lyophilized powder
- Proper cold chain maintenance (2-8°C)
- Appropriate gel base compatible with peptide activity
- Clinical-grade concentrations (0.5-1.6mg/mL)
Warning Signs
- Brief room temperature exposure acceptable if promptly refrigerated
- Homemade topical formulations may lack sterility
Bad Signs
- Discolored or cloudy solutions
- Yellow discoloration or visible particles
- Pre-mixed liquid formulations (LL-37 unstable long-term)
- Non-sterile preparations
- Microbial contamination
References
- Venous Leg Ulcer Trial - Grönberg et al.Wound Repair and Regeneration (2014)
68% ulcer area reduction demonstrated at optimal doses in chronic venous leg ulcers.
- Melanoma Phase I Trial(2015)
Intratumoral LL-37 in melanoma patients demonstrated safety and immune stimulation (NCT02225366).
- MRSA Biofilm Study - Noore et al.PLOS ONE (2019)
>4 log reduction in MRSA biofilms compared to conventional antibiotics.
- Structural Analysis - Wang et al.Journal of Biological Chemistry (2008)
NMR spectroscopy determining 3D structure of LL-37.
Related Peptides
Disclaimer
This information is for educational and research purposes only. Consult a healthcare professional before use.