Independent · non-commercial · publishes on a quarterly cycle|Current cycle 2026 Q3
Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Compound monograph · Immune modulators

LL-37 — compound monograph

37-residue cationic antimicrobial host-defence peptide. Unapproved, research supply. The Institute assesses 2 outcomes for this compound and grades the strongest at low certainty.

Document identifier
CEI-MN-042
Series
Compound monograph
Version
4.3
Published
27 Jan 2025
Last reviewed
27 Apr 2026
Next review
27 Apr 2028
Identifier
10.71829/cei.mono.42
Certainty
Low
Cycle
2025 Q1

§1Identification and status

§1.1Nomenclature

Preferred name
LL-37
Compound class
37-residue cationic antimicrobial host-defence peptide
Assessment series
Immune modulators
Synonyms and codes
human cathelicidin LL-37 · CAP-18(104-140) · hCAP18 fragment
Route as evaluated
Topical and intralesional in clinical studies

§1.2Chemistry

Chemical identifiers are reproduced where they are public. Where a structure has not been published the monograph records not disclosed rather than constructing one.[1]

CAS registry number
154947-66-7
Molecular formula
C205H340N60O53
Average mass
4493.26
Monoisotopic mass
4490.31
ATC classification
not assigned

§1.3Sequence and structural notes

H-Leu-Leu-Gly-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gly-Lys-Glu-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-Asn-Leu-Val-Pro-Arg-Thr-Glu-Ser-OH

The mature 37-residue antimicrobial peptide released from the C-terminus of human cathelicidin hCAP18. It is strongly cationic with a net charge of approximately +6 and forms an amphipathic alpha-helix in membrane-mimetic environments. Its high arginine and lysine content makes counter-ion binding substantial and aggregation on surfaces a practical handling problem.

§1.4Assessment status

The Institute assesses LL-37 across 2 indications and grades the strongest of them at low certainty. Supplied as a research chemical; no marketing authorisation for the uses under which it is supplied.

Distribution of certainty ratingsShare of assessed outcomes at each certainty level.2assessed outcomes
HighModerateLowVery low
Figure 1. Distribution of certainty ratings across the 2 outcomes the Institute assesses for LL-37. A rating attaches to a specific population, comparator and outcome and does not transfer between them.

Table 1. Assessed outcomes for LL-37, ordered by certainty. Each row links to the per-indication evidence extract.

IndicationEffect as recordedCertaintyTrials
Cutaneous wound healing and tissue repairA phase 1/2 trial of intralesional LL-37 in hard-to-heal venous leg ulcers reported greater ulcer-area reduction at intermediate doses than at the…Low1
Immune modulation and adjunctive immunotherapyNo randomised human evidence for systemic immune effectsVery low0
Effects are reproduced as the contributing trials reported them. Where a confidence interval is held it appears on the per-indication extract rather than in this summary table.

References cited on this page

References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.

  1. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q6B Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products. ICH Harmonised Tripartite Guideline 1999;Step 4 version. identifier not held by the Institute

Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.

Nothing published by the Institute is medical advice, a diagnosis, a prescription, a treatment recommendation or a purchasing recommendation. Compounds supplied for research use are not approved for human or veterinary use in any jurisdiction, and a favourable analytical assessment of a supplier is not a statement that any product is safe or effective. The Institute publishes certainty ratings and never recommendations. No telephone number, messaging handle or ordering channel appears anywhere on this site.