What is LL-37 (cathelicidin)?
The short answer
LL-37 is a peptide, a short chain of amino acids.
What it is
LL-37 (cathelicidin): Antimicrobial peptide (37-aa).
Human host-defense peptide.
What people look into
Skin and hair
- 5 sources
- Status as of
- How we source
- Ellum doesn't sell peptides.
Get updates on LL-37 (cathelicidin)
What it is
- Also known as
- cathelicidin ll-37
- How it works
- Human host-defense peptide.
Regulatory status
Not FDA-approved How we label status
As of October 4, 2026, LL-37 (cathelicidin) is not FDA-approved for any use and is not on FDA's 503A bulks list.
- Federal (FDA)
- Not FDA-approved
- 503A compounding
- No category (nomination withdrawn; removed from Cat 2 2026-04-22); not on 216.23 as of 2026-10-07; not an approved-drug component (as of October 7, 2026)
- PCAC history
- Scheduled: PCAC 'before the end of February 2027' (no date set)
Timeline
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Timeline table
| Date | What happened | Source |
|---|---|---|
| FDA warning letter to a compounding pharmacy states that LL-37 was not nominated for inclusion on the 503A bulks list. | FDA, event of November 10, 2021, on fda.gov |
References
Sources as of October 4, 2026
- FDA: www.fda.gov/media/94155/download
- FDA: www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- FDA: www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee
- eCFR: www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-216/subpart-B/section-216.23
- FDA: api.fda.gov/drug/drugsfda.json