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InflammationAnimal / preclinical only

LL-37

Human cathelicidin antimicrobial peptide. Endogenous component of innate immunity with broad-spectrum antimicrobial, immunomodulatory, and wound-healing activity. Researched as a topical and systemic therapeutic across multiple indications; no FDA-approved formulation yet.

Educational only — not medical advice. SmartPeptide does not prescribe, diagnose, or treat. Always consult a licensed healthcare provider before using any peptide, supplement, medication, or protocol.

What the research shows

Robust in-vitro and animal-model evidence for antimicrobial activity (including biofilm disruption), wound healing acceleration, and immunomodulation. Small human topical trials suggest promise for chronic wounds. No approved systemic indication.

What's still experimental

Most therapeutic applications. Optimal route, dose, formulation, and safety profile in systemic use are unknown.

Anecdotal / community reports

Community use for chronic infections, Lyme disease, biofilm-related conditions. These uses are not supported by published RCTs and may risk LL-37's known pro-inflammatory effects in susceptible individuals.

Anecdotal reports are NOT scientific evidence. They reflect personal experience and may not generalize.

FDA approval status

Source: openFDA + DailyMed (NIH/NLM)
No FDA-approved drug label exists for “LL-37”. This peptide is not currently approved by the FDA as a finished pharmaceutical product. Any commercial product claiming FDA approval should be treated with suspicion.

Doses studied in research

No established dose range

What published trials tested or FDA-approved labels specify. Reporting research facts — not a SmartPeptide recommendation.

No FDA-approved or established trial dose range for this peptide. Anecdotal ranges discussed in community forums exist but are not supported by published clinical trials, and SmartPeptide will not publish unverified doses.

This is the honest answer for peptides like BPC-157, IGF-1 LR3, MOTS-c, Epitalon and similar research compounds — robust human dose- ranging studies have not been published. Always work with a licensed clinician familiar with experimental peptides if you are considering any use.

FDA enforcement & recalls

Live · openFDA Drug Enforcement API
Total actions
2
recalls + withdrawals
Ongoing
1
not yet completed
Class I (serious)
0
health hazard / death risk
  • Class IITerminated· Voluntary: Firm initiated
    FDA record

    LL-37 2 mg/mL (5 mL) Injection, 5 mL vials, Rx only, Farmakeio 1736 N Greenville Ave Richardson, TX 75081 USA

    Reason: Lack of Assurance of Sterility: deviations from Current Good Manufacturing Practices (CGMP) that call into question the sterility of products intended to be sterile.

    Apr 5, 2022·North American Custom Laboratories, LLC dba FarmaKeio Superior Custom Compounding
  • Class IIOngoing· Voluntary: Firm initiated
    FDA record

    LL-37, 2000 MCG/ML, 2 ML vial, The Guyer Institute of Molecular Medicine, Indianapolis, IN

    Reason: Lack of Assurance of Sterility: due to concerns with production processes which cannot assure sterility of products intended to be sterile.

    Nov 30, 2020·Advanced Nutriceuticals, LLC
FDA classifications: Class I = reasonable probability of serious adverse health consequences or death. Class II = temporary or medically reversible adverse consequences. Class III = unlikely to cause adverse health consequences.

Mechanism & targets

ChEMBL · UniProt · Open Targets

Molecule (ChEMBL)

View on ChEMBL
Formula
C205H341N61O52

Protein targets (UniProt)

  • Cathelicidin antimicrobial peptide
    P49913gene: CAMPHomo sapiens· 170 aaReviewed

    Antimicrobial protein that is an integral component of the innate immune system (PubMed:14978112, PubMed:16637646, PubMed:18818205, PubMed:22879591, PubMed:9736536). Binds to bacterial lipopolysaccharides (LPS) (PubMed:16637646, PubMed:18818205). Acts via neutrophil N-formyl peptide receptors to enhance the release of CXCL2 (PubMed:22879591). Postsecretory processing generates multiple cathelicidin antimicrobial peptides with various lengths which act as a topical antimicrobial defense in sweat…

  • Cathelicidin antimicrobial peptide
    Q1KLX2gene: CAMPPongo pygmaeus· 170 aaReviewed

    Antimicrobial protein that is an integral component of the innate immune system (By similarity). Binds to bacterial lipopolysaccharides (LPS) (By similarity). Acts via neutrophil N-formyl peptide receptors to enhance the release of CXCL2 (By similarity). Postsecretory processing generates multiple cathelicidin antimicrobial peptides with various lengths which act as a topical antimicrobial defense in sweat on skin (By similarity). The unprocessed precursor form, cathelicidin antimicrobial peptid…

  • Cathelicidin antimicrobial peptide
    Q1KLX7gene: CAMPMacaca fascicularis· 170 aaReviewed

    Antimicrobial protein that is an integral component of the innate immune system (By similarity). Binds to bacterial lipopolysaccharides (LPS) (By similarity). Acts via neutrophil N-formyl peptide receptors to enhance the release of CXCL2 (By similarity). Postsecretory processing generates multiple cathelicidin antimicrobial peptides with various lengths which act as a topical antimicrobial defense in sweat on skin (By similarity). The unprocessed precursor form, cathelicidin antimicrobial peptid…

Live research

PubMed · ClinicalTrials.gov · Europe PMC · OpenAlex
PubMed papers
4,189
total
Human studies
0
MeSH: humans
Clinical trials
0
published
Active trials
6
98 total registered

Clinical trials (ClinicalTrials.gov)

All trials for "LL-37 OR cathelicidin"

Europe PMC — 189,232 additional records

Includes EU/UK studies and PubMed Central full-text articles. Often surfaces research weeks before PubMed indexes it.

Research volume (OpenAlex topic graph)

Total works
1,130,738
all years
Last 5 years
426,133
recent activity
Open access
1,109,709
freely readable
OA share
98%
of all works

Human clinical evidence

Semantic Scholar · AI TLDRs · influence-ranked
Semantic Scholar API is currently rate-limited.

Human-study summaries for “LL-37 OR cathelicidin LL-37” are available on Semantic Scholar but the shared free-tier API quota is exhausted right now. Try refreshing in a few minutes, or check the PubMed and Europe PMC panels above for the same literature.

Research funding & verification

NIH RePORTER · CrossRef DOI registry

NIH-funded research

U.S. National Institutes of Health
Funded projects
140
all years
Top award sum
$22.6M
aggregate USD
Years covered
20
research span
Largest active / recent grants

Publication landscape

CrossRef · DOI registry
Indexed works (CrossRef)
1,802,061
all DOIs registered
Retracted papers
0
no retractions on record
Top funders of indexed research
  • National Natural Science Foundation of China30,491 works
  • National Science Foundation4,136 works
  • National Key Research and Development Program of China3,890 works
  • National Institutes of Health3,682 works
  • Fundamental Research Funds for the Central Universities3,066 works
  • National Research Foundation of Korea2,573 works

Funder diversity is a credibility signal. Research concentrated in a single drug company's funding warrants more scrutiny than research funded across NIH, charities, and academic grants.

Preprints — cutting edge

bioRxiv · medRxiv · via Europe PMC

Preprints have NOT been peer-reviewed. They are early research shared by authors before formal validation. Treat findings as preliminary.

Showing 6 of 1,954 preprints indexed by Europe PMC.

Known risks

Cytotoxicity at high concentrations (LL-37 can be toxic to human cells, not just bacteria). Pro-inflammatory effects in certain contexts (psoriasis, lupus). Limited human pharmacokinetic data.

Reported side effects

Topical: skin irritation. Systemic: poorly characterized in humans. Theoretical immune-modulation concerns.

FDA adverse event reports (FAERS)

Updated quarterly by FDA
No reports found in the FDA Adverse Event Reporting System for “LL-37”. This is normal for research-only peptides that are not marketed as FDA-approved drugs.

What requires medical supervision

Not FDA-approved. Should only be considered under a clinician familiar with antimicrobial peptide research.

Questions for your clinician

  • Is there published human evidence for my specific indication?
  • What's the risk of immune dysregulation in my case?
  • Are there FDA-approved alternatives we should try first?

Editorially curated references

Discussions about LL-37

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