LL-37
Also known as: Cathelicidin, CAP18
Key Facts: LL-37
- Category
- Immune
- FDA Status
- Not FDA Approved
- Clinical Status
- Investigational - Clinical trials for wound healing
- Administration
- Subcutaneous injection or topical
- Typical Dose
- 100-200 mcg daily
- Frequency
- Once daily
- Evidence Level
- Human Trials
- Duration
- Variable by protocol
What to Expect
A naturally occurring antimicrobial peptide and the only human cathelicidin. Part of the innate immune system with broad-spectrum antimicrobial activity.
Mechanism of Action
LL-37 directly kills bacteria, fungi, and some viruses by disrupting their cell membranes. It also modulates the immune response, promotes wound healing, reduces inflammation, and has anti-biofilm activity against bacterial infections.
Research Summary
Research demonstrates broad antimicrobial activity including against antibiotic-resistant bacteria. Studies show wound healing benefits, anti-biofilm effects, and immune modulation. Being investigated for chronic infections and wound healing applications.
Dosing Information
Typical Dosingⓘ
Community experience
100-200 mcg daily
50-300 mcg daily
Once daily
Antimicrobial peptide. Used for infections, biofilm disruption. Some use higher doses for acute infections.
Research Dosingⓘ
Scientific studies
Doses from research protocols
Doses from Studies
100-200 mcg subcutaneous
Varies by indication
Duration
Variable by protocol
Administration
Subcutaneous injection or topical
Timing & Administration
Best Time to Take
Morning
As directed, typically once daily
Food Recommendation
With or without food
Why This Timing?
LL-37 is an antimicrobial peptide. Morning use supports daytime immune surveillance.
Possible Side Effects
Not everyone experiences these effects. Individual responses vary based on dosage, duration, and personal factors.
- ●Injection site reactions (common)
- ●Skin toxicity (ulcers, burning)
- ●Allergic reactions
- ●May trigger histamine release - use caution with MCAS or histamine sensitivity
- ●May contribute to autoimmune conditions
- ●High-dose toxicity concerns
- ●Limited long-term safety data
References
Related Peptides
Peptides commonly compared with LL-37 or used in similar applications.
Thymosin Alpha-1
Clinical TrialsA naturally occurring thymic peptide that enhances immune function. Approved in over 35 countries for hepatitis B/C and as an immune adjuvant.
ImmuneKPV
PreclinicalA tripeptide derived from alpha-melanocyte stimulating hormone (α-MSH). Known for potent anti-inflammatory effects, particularly in the gut.
ImmuneVIP
Clinical TrialsA naturally occurring peptide with immunomodulatory and anti-inflammatory effects. Being studied for ARDS, pulmonary hypertension, and autoimmune conditions.
ImmuneEnfuvirtide
FDAA peptide HIV fusion inhibitor that blocks viral entry into cells. First approved drug in the fusion inhibitor class.
ImmuneTB-500
Clinical TrialsA synthetic 17-amino acid fragment of Thymosin Beta-4 (TB-4). NOT the same as TB-4 - TB-500 has a longer half-life (~2-4 days vs ~2 hours) and is the active region responsible for tissue repair and cell migration. Note: Many vendors mislabel TB-4 as 'TB-500' in premixed products.
HealingMatrixyl 3000
ResearchAn advanced version of Matrixyl combining two peptides for enhanced anti-aging effects. Targets both collagen production and inflammation.
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Educational Information Only
This information is provided for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare providers before making any decisions about peptides or other substances. The protocols listed reflect doses observed in research studies, not recommendations.