For clinicians
Cathelicidin (LL-37) for prescribers: status, evidence and what FDA has said
A neutral reference. It reports Cathelicidin (LL-37)'s regulatory status, the quality of its human evidence and what FDA has said about it. It does not suggest a dose, a protocol or a source.
Status reviewed 2026-05-19 · By the Grey Peptides Editorial Board · Regulatory fields generated from our tracker
| Also known as | LL-37, hCAP18 |
| FDA approval | Not FDA-approved |
| Compounding (503A) | Not compoundable; PCAC review due by Feb 2027 |
| Outsourcing (503B) | No 503B status recorded |
| FDA advisory committee | Scheduled for review before the end of February 2027 |
| WADA 2026 List | Prohibited (S0 catch-all) |
| WADA 2027 List | Prohibited (S0 catch-all) |
| Evidence grade | Low |
| Status reviewed | 2026-05-19 |
What FDA has said
FDA lists Cathelicidin LL-37 among substances it has identified as potentially presenting significant safety risks outside Category 2 (page current as of 2026-04-22). In FDA's words:
Compounded drugs containing cathelicidin LL-37 may pose risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and API characterization. FDA lacks sufficient safety-related information regarding cathelicidin LL-37 to know whether the drug would cause harm when administered to humans. Nonclinical research findings suggest detrimental effects on male reproduction and that this drug can be protumorigenic in some tissues.
Monitoring: what the literature does and does not say
- No label. Cathelicidin (LL-37) has no FDA-approved label, and therefore no labelled guidance on monitoring.
- What FDA has said about its risks is quoted above, from its list of bulk substances that may present significant safety risks.
These are gaps, not a monitoring schedule. This page does not supply one, and for a compound in this position the human evidence would not support one.
Compounding: where it stands
Today's position for Cathelicidin (LL-37): Not compoundable; PCAC review due by Feb 2027. An FDA advisory committee's vote is a non-binding recommendation; until FDA acts, a vote does not change what may be compounded. Our explainer on the 503A and 503B categories sets out what each status means, and the regulatory tracker is updated as FDA acts.
The evidence
The 37-residue active peptide released from the human cathelicidin precursor hCAP-18 (encoded by the CAMP gene), with direct microbicidal activity and pleiotropic effects on wound healing, angiogenesis, and innate immune signaling.
The encyclopedia entry lists the human and animal studies we hold, each with its PMID.
What this page leaves out
Doses, regimens, cycle lengths and sources. That is deliberate. A reference that reports status and evidence is useful only if it is not also a protocol, and for a compound in this position there is no approved one to report.
Sources
- US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Content current as of 2026-04-22; read 2026-10-01. FDA
- Grey Peptides regulatory tracker, row for Cathelicidin (LL-37), reviewed 2026-05-19. Tracker · dataset
- World Anti-Doping Agency. Prohibited List 2027, dated August 26, 2026, in force January 1, 2027. WADA
This page is a reference for qualified professionals. It is not medical advice, it does not recommend any treatment, and it is not a substitute for the prescriber's own judgement and their state and federal obligations.
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