LL37
Cathelicidin Antimicrobial Peptide
LL-37 is a naturally occurring antimicrobial peptide (AMP) belonging to the cathelicidin family. It plays a vital role in the immune system by exhibiting broad-spectrum antibacterial, antiviral, antifungal, and anti-inflammatory properties. LL-37 is produced from the human cathelicidin antimicrobial peptide (CAMP) gene and is primarily found in immune cells, epithelial tissues, and wound sites. Its key function is to defend the body against infections by disrupting microbial cell membranes and modulating immune responses.
Beyond its antimicrobial capabilities, LL-37 has been studied for its role in wound healing, tissue regeneration, and immune system modulation. It has shown potential in treating chronic infections, inflammatory conditions, and autoimmune disorders. Additionally, research suggests it may support gut health, combat biofilm-related infections, and aid in conditions such as Lyme disease, chronic wounds, and even cancer therapy.
Protocols
1. Wound Healing & Tissue Regeneration
Dosage: 10–50 mcg per injection, 1–2 times daily
Cycle: 4–6 weeks, reassess based on healing progress
Administration: Subcutaneous (SC) injection near the wound site or topical application mixed with a carrier cream
Stacking: Works well with BPC-157 and TB-500 for enhanced healing
Expected Benefits: Accelerated wound closure, reduced inflammation, improved tissue regeneration
2. Immune System Support & Antimicrobial Effects
Dosage: 50–100 mcg per injection, 3–5 times per week
Cycle: 4–8 weeks, followed by a break
Administration: SC injection, systemic use for immune modulation
Stacking: Often combined with Thymosin Alpha-1 for enhanced immune response
Expected Benefits: Increased resistance to infections, reduced inflammation, improved immune balance
3. Chronic Infections & Biofilm Disruption (e.g., Lyme Disease, MRSA, UTIs)
Dosage: 50–100 mcg per injection, daily or every other day
Cycle: 6–8 weeks, reassess based on symptoms
Administration: SC injection or nebulised (for respiratory infections)
Stacking: Can be combined with antibiotics or herbal antimicrobials to break biofilms
Expected Benefits: Enhanced pathogen clearance, reduced bacterial biofilm formation, improved symptom resolution
4. Gut Health & Inflammatory Bowel Disease (IBD)
Dosage: 50–100 mcg per injection, 3–5 times per week
Cycle: 6–8 weeks, followed by evaluation
Administration: SC injection or oral administration (low-dose for gut lining repair)
Stacking: Pairs well with BPC-157 and KPV peptide for gut healing
Expected Benefits: Reduced intestinal inflammation, improved gut barrier integrity, symptom relief in conditions like Crohn’s and ulcerative colitis
5. Skin Conditions (Eczema, Psoriasis, Acne, Rosacea)
Dosage: 10–50 mcg, applied topically once daily
Cycle: 4–8 weeks, or as needed
Administration: Mixed with a carrier (e.g., aloe vera, coconut oil) and applied to affected areas
Stacking: Can be combined with GHK-Cu for enhanced skin repair
Expected Benefits: Reduced skin inflammation, antimicrobial effects, improved skin texture
Further reading
LL-37 functions by disrupting the membranes of pathogenic microbes, making it highly effective against a wide range of bacteria, viruses, and fungi. Unlike conventional antibiotics, LL-37 also has immunomodulatory properties, allowing it to regulate inflammatory responses and promote healing. This makes it particularly useful in treating antibiotic-resistant infections and chronic inflammatory conditions.
In wound healing, LL-37 enhances cellular migration and angiogenesis, which are crucial for tissue repair. Studies suggest that it can significantly reduce healing time for chronic wounds such as diabetic ulcers. Additionally, its ability to disrupt bacterial biofilms makes it a promising candidate for treating persistent infections that are resistant to traditional antibiotics.
LL-37’s effects on the immune system extend beyond infection control. It has been shown to modulate cytokine production, reducing excessive inflammation while supporting a balanced immune response. This has led to interest in its use for autoimmune conditions, respiratory infections, and gut health disorders such as IBD and leaky gut syndrome.
One area of growing interest is its potential role in cancer therapy. Preliminary research indicates that LL-37 may have tumour-suppressing effects in certain cancers, although in some contexts, it may promote tumour progression. The dual role of LL-37 in cancer highlights the complexity of its functions and underscores the need for further research.
Despite its promising applications, LL-37 should be used with caution. Overuse or high doses may lead to excessive immune stimulation or unwanted inflammatory effects. Additionally, as it is still under investigation for various medical applications, its long-term safety profile is not yet fully established.
References
- Vandamme, D., et al. (2012). "Cathelicidins: Immunomodulatory antimicrobial peptides." Nature Reviews Microbiology, 10(9), 699–710.
Dürr, U. H., Sudheendra, U. S., & Ramamoorthy, A. (2006). "LL-37, the only human member of the cathelicidin family of antimicrobial peptides." Biochimica et Biophysica Acta, 1758(9), 1408–1425.
Kahlenberg, J. M., & Kaplan, M. J. (2013). "Little peptide, big effects: The role of LL-37 in inflammation and autoimmune disease." Journal of Immunology, 191(10), 4895–4901.
Yu, J., et al. (2010). "The role of cathelicidin LL-37 in inflammatory skin diseases." Dermatology Research and Practice, 2010, 821710.
Overhage, J., et al. (2008). "Human host defense peptide LL-37 prevents bacterial biofilm formation." Infection and Immunity, 76(9), 4176–4182.