37-residue peptide derived from human cathelicidin
Cathelicidin LL-37
A 37-residue peptide derived from the human cathelicidin protein. No FDA-approved drug product exists, and FDA lists it among bulk substances whose compounding nominations were withdrawn.
Why people are interested in Cathelicidin LL-37
A 37-residue peptide derived from the human cathelicidin protein. No FDA-approved drug product exists, and FDA lists it among bulk substances whose compounding nominations were withdrawn.
- Antimicrobial peptides— a research-category classification, not a claimed use
- Preclinical research compounds— a research-category classification, not a claimed use
Where the interest comes from differs by compound: published research, an approved use, clinical discussion, community discussion and vendor claims are different things. This page keeps them apart — the sections below say which kind of source supports each statement.
Quick facts
- Molecular weight
- 4493 g/mol
- Sequence length
- 37 chars
- CAS number
- 154947-66-7
- PubChem CID
- 16198951
0 evidence records indexed · 0 clinical trials · last reviewed 15 September 2026
Research at a glance
No evidence records in this file yet.
What has actually been studied
What is still unknown
What we know
Editorial reading of the records below, labelled as Therapept analysis. How records are built
What remains uncertain
Preparation and handling
Lyophilized peptides ship as powders; whatever happens next involves diluents, concentrations and storage conditions that are compound- and product-specific. Therapept’s preparation guides explain the vocabulary and the arithmetic; the product’s own documentation states its requirements.
United States regulatory status
No FDA-approved product
- No approved drug product exists in Drugs@FDA.
- Listed as “Cathelicidin LL-37” on FDA's table of bulk substances nominated for compounding and withdrawn. FDA's published concerns include immunogenicity risk for certain routes, peptide-related impurities and API characterisation, and insufficient safety information.
- FDA's entry also notes nonclinical findings suggesting detrimental effects on male reproduction and that the substance can be protumorigenic in some tissues.
- Not named on the WADA 2026 Prohibited List.
Regulatory status describes how a substance is classified. It is not a safety assessment, and it says nothing about the quality of any particular material.
Technical identity
- Compound class
- 37-residue peptide derived from human cathelicidin; antimicrobial peptide
- Sequence
- LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
- Molecular formula
- C205H340N60O53
- Molecular weight
- 4493 g/mol
- CAS number
- 154947-66-7
- PubChem CID
- 16198951
- Research categories
- Antimicrobial peptides, Preclinical research compounds
Sources
Last reviewed 15 September 2026 · Compiled by Therapept Editorial · How these records are built