Peptide data sheet
LL-37
Recovery · Cathelicidin · hCAP-18 · CAMP
Verdict
unprovenThe unproven label reflects a genuinely double-edged evidence base: LL-37 has a large body of laboratory work on killing microbes, shaping immune responses, and supporting wound repair, but controlled human trials establishing a therapeutic benefit are minimal, and the same peptide has been implicated in inflammatory skin disease, so the honest read is interesting-but-unsettled rather than a green light.
By MrPepTalks Editorial
Reviewed for scientific accuracy · research information, not medical advice
Last updated Reviewed
Quick answer
LL-37 is the only known human cathelicidin, a 37-amino-acid host-defense peptide cleaved from the hCAP-18 protein and released by neutrophils, skin cells, and other tissues. It is commonly researched for antimicrobial activity against bacteria and biofilms, for immune-signaling roles, and for wound healing. The evidence is largely preclinical, and LL-37 is notably context-dependent: the same peptide is studied both for healing and as a driver of inflammatory skin conditions. It is not FDA-approved and is sold for research use only.
- Class
- Cationic antimicrobial host-defense peptide; sole human cathelicidin (cleaved from hCAP-18, CAMP gene)
- Half-life
- short; rapidly bound and degraded in tissue, not well characterized in humans (reported)
- FDA status
- Not FDA-approved. Studied in preclinical and early research; sold for laboratory research use only, not for human use.
- WADA banned?
- No
Which form actually works?
Topical / wound context
Unproven
The direction with the most host-defense and wound-repair literature behind it, since LL-37 is naturally active in skin and mucosal surfaces. Interest is real, but controlled human data for a topical wound-healing benefit is thin, and because LL-37 is also implicated in inflammatory skin disease the same route carries a genuine two-sided-effect caveat.
Injectable / systemic
Unproven
The systemic-research direction people ask about, based mostly on cell and animal work on antimicrobial and immune-modulating activity. Human data for a systemic benefit is essentially absent, and LL-37's context-dependent, sometimes pro-inflammatory behavior makes this the least-characterized and most uncertain route, so it stays firmly unproven.
Third-Party Testing & Certificate of Analysis (COA)
A certificate of analysis (COA) is a lab document that reports what a specific batch of material actually contains. Reputable research suppliers publish one for every batch, tied to a lot number you can match against the vial you received.
- HPLC — purity
- High-performance liquid chromatography reports purity as a percentage: how much of the sample is the intended compound rather than impurities.
- Mass spectrometry (MS) — identity
- Mass spectrometry confirms identity by measuring the sample's molecular mass, so it matches the peptide the label names.
It also matters who ran the test. In-house results come from the seller's own lab; an independent third-party lab has no stake in the result, so its COA generally carries more weight. Look for a named testing laboratory, a batch or lot number, and a test date that lines up with the vial in hand.
New to reading one? This guide walks through a COA line by line: how to read a peptide COA.
Sources
- Reinholz M, Ruzicka T, Schauber J. Cathelicidin LL-37: an antimicrobial peptide with a role in inflammatory skin disease. Ann Dermatol, 2012.
- Ramos R et al. Wound healing activity of the human antimicrobial peptide LL37. Peptides, 2011.
- Kahlenberg JM, Kaplan MJ. Little peptide, big effects: the role of LL-37 in inflammation and autoimmune disease. J Immunol, 2013.
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