LL-37
Also sold as: Cathelicidin LL-37, cathelicidin antimicrobial peptide, hCAP-18, CAP-18, LL-37 (CAP-18), LL-37 acetate, ropocamptide
LL-37 is not an FDA-approved drug for any indication; its only presence in an FDA drug database is as bulk ingredient listings in the National Drug Code Directory, and FDA states that assignment of an NDC number 'does not in any way denote FDA approval of the product'. LL-37 was nominated for use in pharmacy compounding under section 503A and FDA lists Cathelicidin LL-37 under 'Bulk drug substances nominated but withdrawn' — substances previously in category 2, the category for significant safety risks, whose nominations the nominators withdrew — and it appears in none of Categories 1, 2 or 3 of the 503A list updated 14 May 2026. FDA states it lacks sufficient safety-related information regarding cathelicidin LL-37 to know whether the drug would cause harm when administered to humans, and that nonclinical research findings suggest detrimental effects on male reproduction and that the drug can be protumorigenic in some tissues. In the largest trial to administer LL-37 to people — a phase IIb double-blind randomised placebo-controlled study of a topical formulation in 148 patients with hard-to-heal venous leg ulcers — the investigators reported that 'Efficacy analysis performed on the full study population did not identify any significant improvement in healing in patients treated with LL-37 as compared with the placebo.'
Which molecule this is. LL-37 is the mature 37-residue C-terminal peptide released by proteolytic cleavage from the human cathelicidin precursor protein hCAP-18. Two disambiguations carry most of this record. FIRST, LL-37 IS ENDOGENOUS. It is already present in human neutrophils, epithelia, saliva, gingival crevicular fluid and wound fluid, with nobody administering anything. That single fact reverses the meaning of most of the literature filed under its name: a study 'of LL-37' in humans is usually a study that MEASURED a peptide the subject already had, frequently as a readout of vitamin D status or smoking. It is not a study of a drug. SECOND, NAMES. The synthetic peptide taken into clinical trials carries the non-proprietary name ropocamptide; FDA files the compounding entry as 'Cathelicidin LL-37'; and FDA's National Drug Code Directory carries separate bulk-ingredient entries reading 'LL-37', 'LL-37 (CAP-18)' and 'LL-37 Acetate' from four different labelers, one of which records the active ingredient as ROPOCAMPTIDE. A label reading 'LL-37' does not by itself identify a salt form.
FDA status
FDA has not approved this and it is not in active development toward approval. That says nothing about whether it is being sold — most substances in this category are.
Not approved, and — this is the part that required a decision rather than a lookup — not investigational either. ABSENCE FROM Drugs@FDA, CHECKED PROPERLY. A NOT_FOUND from one wrong field is an artifact of the query, not a fact about the database, so the openFDA drug/drugsfda endpoint was queried on 2026-08-02 across every field that could carry it: openfda.generic_name, openfda.substance_name, products.active_ingredients.name and products.brand_name, each for 'LL-37', 'cathelicidin' and 'ropocamptide', plus unfielded full-text searches for all three. Every one returned no match. There is no NDA, no ANDA and no BLA. WHAT DOES EXIST is four entries in FDA's NDC Directory, every one with marketing_category 'BULK INGREDIENT' and a null application number — recorded separately under fdaFindings, because a bulk-ingredient listing is the single most misread artifact in this market. WHY NOT 'investigational'. LL-37 did have a real programme with a real sponsor: Pergamum AB and then Promore Pharma AB developed it under the non-proprietary name ropocamptide, through a first-in-man trial and a 148-patient phase IIb. That programme is over. Promore Pharma entered voluntary liquidation by decision of an extraordinary general meeting on 5 October 2023, having stated that the climate for the share issues needed to finance continued development of ropocamptide was very challenging, and the listed entity was then used for a reverse acquisition of an unrelated medical-device business. The vocabulary here is explicit that a terminated or abandoned programme is not investigational, and no successor sponsor, no new registered trial and no active recruitment administering LL-37 was identified as of 2026-08-02. 'In clinical trials' is sold on the strength of trials that stopped years ago; this is one of those.
“Inclusion in the NDC Directory does not indicate that FDA has verified the information provided or that the products are FDA-approved. … Assignment of an NDC number does not in any way denote FDA approval of the product. Any representation that creates an impression of FDA approval because a product has an NDC number is misleading and violates federal law.”Checked against the source on .
503A compounding
The nominator withdrew the nomination. This is not a legalisation event — the substance is not on the 503A bulks list and remains non-compoundable.
Read the direction of travel, because the market reads it backwards. Cathelicidin LL-37 was PREVIOUSLY IN CATEGORY 2 — the category FDA reserves for substances that may present significant safety risks — and it left because the nominators withdrew, not because FDA resolved anything in its favour. It did not enter Category 1. It is not on the 503A bulks list. It appears in none of Categories 1, 2 or 3 of the list updated 2026-05-14, verified on 2026-08-02 by fetching that PDF with a browser user-agent and extracting its text: zero hits for 'LL-37', 'cathelicidin' and 'ropocamptide' across all seven pages. Status moved sideways, and FDA left its safety concerns published on a page it never took down. NOT ONE OF THE SEVEN. Cathelicidin LL-37 was not among the substances before the Pharmacy Compounding Advisory Committee on 23-24 July 2026, so none of what that committee recommended reaches it — see fdaFindings.
“Bulk drug substances nominated but withdrawn — This list of bulk drug substances previously in category 2 of the interim policies were withdrawn by the nominators. … Cathelicidin LL-37”Checked against the source on .
Evidence
There is human data, but efficacy is not established. This includes programmes that were tested and failed.
ADMINISTRATION CHECK RUN, AND IT MATTERED. LL-37 is endogenous, which is the exact condition that reduces MOTS-c and TB-500 from an apparent handful of human RCTs to an actual zero, so every candidate study was opened rather than counted. The count, performed 2026-08-02: an intervention query for 'LL-37' on ClinicalTrials.gov returns 20 studies. EIGHTEEN of them do not administer it — they measure endogenous LL-37 in saliva, serum, gingival crevicular fluid or peri-implant sulcus fluid, most often as a readout of vitamin D supplementation, smoking exposure or periodontal disease. Two administer it: NCT02225366 (M.D. Anderson with NCI, intratumoral injection in melanoma, phase 1/2, 4 participants ACTUAL, completed 2020-11-24, results posted) and NCT04098562 (topical cream in diabetic foot ulcers, Universitas Indonesia, last known status UNKNOWN since 2019, enrolment only ESTIMATED — treat it as unreported). THE TWO THAT COUNT ARE NOT ON ClinicalTrials.gov AT ALL, which is why a registry-only search understates this compound. Both were European and both administered synthetic LL-37 topically to human wounds: Grönberg et al. 2014, a first-in-man randomised placebo-controlled trial in 34 participants with venous leg ulcers, sponsor Pergamum AB; and the trial cited above, HEAL LL-37 (EudraCT 2018-000536-10), a phase IIb double-blind randomised placebo-controlled study in 148 patients with hard-to-heal venous leg ulcers, sponsor Promore Pharma AB. Both abstracts were retrieved through the NCBI E-utilities efetch endpoint and the phase IIb was opened in full on PMC. LL-37 was given to people. WHY THE TIER IS NOT HIGHER. The phase IIb did not succeed. The investigators reported that efficacy analysis in the full study population did not identify any significant improvement in healing versus placebo, and the positive result they describe is confined to a POST HOC analysis in the subgroup with large target wounds — the authors' own word is 'post hoc', and their conclusion asks for 'a further study adequately powered' to assess that group. That study was never run: the sponsor liquidated in October 2023. This tier is assigned because the vocabulary reserves 'promising-but-unproven' for programmes with a human signal that were tested and not established, explicitly including ones that failed. This is one that failed. THE GAP THAT MATTERS MOST IS ROUTE AND INDICATION. Every human administration of LL-37 identified here was either topical application to a chronic leg ulcer under compression, or injection directly into a cutaneous melanoma lesion. Nothing in this evidence base describes systemic subcutaneous or nasal use, and nothing in it addresses immune support, gut health, chronic infection or biofilm — the claims the consumer market is built on. A trial of a wound gel is not evidence for an injected vial.
“Efficacy analysis performed on the full study population did not identify any significant improvement in healing in patients treated with LL-37 as compared with the placebo.”Checked against the source on .
What FDA found
FDA’s own words. These are the most citable thing on this site, and the least likely to appear anywhere funded by someone selling the compound.
FDA lists Cathelicidin LL-37 in the table headed 'Bulk drug substances nominated but withdrawn' on its page identifying bulk drug substances that may present significant safety risks — a list FDA describes as substances previously in category 2 of the interim policies whose nominations were withdrawn by the nominators.
Verified by fetching the page with a browser user-agent and parsing its two tables rather than reading the flattened text, because the flattened text does not tell you which table a row is in and that is the entire question. Table 1 is Category 2 and holds fifteen rows; 'Cathelicidin LL-37' is not in it. Table 2 is the withdrawn table and holds seventeen entries; 'Cathelicidin LL-37' is one of them, filed alphabetically between BPC-157 and CJC-1295. The practical consequence is the one people get wrong: withdrawal moved LL-37 off Category 2 and nowhere else. FDA's stated concerns about it stayed published.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — FDA, 22 April 2026“This list of bulk drug substances previously in category 2 of the interim policies were withdrawn by the nominators.”
Checked against the source on .Cathelicidin LL-37 appears in none of Categories 1, 2 or 3 of FDA's list of bulk drug substances nominated for use in compounding under section 503A, updated 14 May 2026.
Recorded to close a misreading, not to establish the status — absence from this document proves absence and nothing more, which is why the withdrawal above is sourced to the safety-risks page instead. Verified on 2026-08-02 by fetching the PDF with a browser user-agent and extracting all seven pages locally: zero hits for 'LL-37', 'LL37', 'cathelicidin' and 'ropocamptide'. This is precisely the trap that produced a false 'never nominated' reading elsewhere in this library. LL-37 is invisible in the document most people check, and present in the one they do not.
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act — FDA, 14 May 2026Checked against the source on .Cathelicidin LL-37 was not among the bulk drug substances before FDA's Pharmacy Compounding Advisory Committee at its meeting of 23-24 July 2026.
Verified by fetching the agenda PDF and extracting its text on 2026-08-02: zero hits for 'LL-37' and zero for 'cathelicidin'. The substances the agenda does name are BPC-157, KPV, TB-500, MOTS-c, semax, epitalon and emideltide (DSIP). This matters because of what is about to be written about that meeting. Coverage of the July 2026 committee recommendations is being read across the peptide category as a general softening, and LL-37 was not in the room. It received no recommendation, favourable or otherwise, and nothing about its position changed in July 2026.
Pharmacy Compounding Advisory Committee Meeting, July 23-24, 2026 — Agenda — FDA, 23 July 2026Checked against the source on .LL-37's only presence in an FDA drug database is as bulk ingredient listings in the National Drug Code Directory. As of the openFDA data current to 31 July 2026 there are four, from Qingdao Biopeptek Co., Ltd., Nanjing Chengong Pharmaceutical Co., Ltd., DARMERICA, LLC and Pure Peptide Pharmaceuticals Inc., every one carrying the marketing category 'BULK INGREDIENT', the dosage form POWDER, and no application number.
The most misread artifact in this market, recorded so it can be checked in one request. An NDC is a listing identifier, not an approval, and FDA says so in terms: 'Assignment of an NDC number does not in any way denote FDA approval of the product. Any representation that creates an impression of FDA approval because a product has an NDC number is misleading and violates federal law.' FDA's page also describes the directory as containing 'finished and unfinished drugs' and as covering 'approved and unapproved drugs'. A supplier holding an NDC for LL-37 powder has registered and listed; it has not been approved, reviewed or endorsed. Two details worth reading. The Nanjing listing records its active ingredient as ROPOCAMPTIDE under the generic name 'LL-37 (CAP-18)', which is the clearest single confirmation in an FDA database that the drug-candidate name and the research-peptide name denote the same molecule. And two of the four listings record marketing start dates of 2025-12-08 and 2026-05-01 — this is current supply, not a legacy entry.
openFDA National Drug Code Directory API — query for generic_name "LL-37" — FDA, 31 July 2026Checked against the source on .
Documented safety signals
FDA states that compounded drugs containing cathelicidin LL-37 may pose a risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and active pharmaceutical ingredient characterization, and that FDA lacks sufficient safety-related information regarding cathelicidin LL-37 to know whether the drug would cause harm when administered to humans.
Note the shape of the finding: it is a statement about missing information, not a report of harm, and those are different things that get collapsed in both directions. It cuts against 'no adverse events have been reported, so it is safe' — FDA is saying the information needed to answer the question does not exist. It equally does not establish that LL-37 has hurt anyone. Read it against this record's evidence section rather than alone. Human tolerability data does exist for one route: the investigators in both venous-leg-ulcer trials reported that topical LL-37 was well tolerated, and the 2014 trial reported no safety concerns regarding local or systemic adverse events. That is a finding about a wound gel applied to skin. FDA's concern is expressly about routes of administration and about what is in a bulk substance, and neither of those is answered by a topical trial.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — FDA, 22 April 2026“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.”
Checked against the source on .FDA states that nonclinical research findings suggest detrimental effects on male reproduction and that cathelicidin LL-37 can be protumorigenic in some tissues.
The most specific negative finding FDA publishes about this substance, and it is worth isolating from the boilerplate it sits next to. The immunogenicity and characterization language above is close to identical across a dozen entries on FDA's page; this sentence is written for LL-37 alone. Only three of the seventeen withdrawn entries carry a substance-specific nonclinical finding at all. Two limits, stated because the finding is strong enough not to need overstating. It is NONCLINICAL — FDA's word — so it does not describe an observed effect in a person. And FDA gives no citation to the underlying research on this page, so what is verifiable here is that FDA said it, not the primary data behind it. It is also the reason this record's marketing gap is not merely an efficacy gap. LL-37 is sold into a market that reads an endogenous human peptide as inherently safe because the body already makes it. FDA's stated concerns run the other way, and 'protumorigenic in some tissues' is not a claim any seller of this compound discloses.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — FDA, 22 April 2026“Nonclinical research findings suggest detrimental effects on male reproduction and that this drug can be protumorigenic in some tissues.”
Checked against the source on .
Questions people actually ask
Every answer cites the document behind it. Where the honest answer is “nobody knows”, that is the answer you will get.
- Is LL-37 FDA-approved?
No. LL-37 is not an approved drug product in the United States under any name — not LL-37, not cathelicidin LL-37, and not ropocamptide, the non-proprietary name under which it was developed as a drug candidate. Searching FDA's Drugs@FDA database through the openFDA drug/drugsfda endpoint on 2 August 2026 across generic name, substance name, active-ingredient name and brand name, plus unfielded full-text search, returned no match for any of those three names: there is no NDA, ANDA or BLA. What does exist, and what gets mistaken for approval, is a listing. LL-37 appears in FDA's National Drug Code Directory as four bulk-ingredient entries from peptide API suppliers, each carrying an NDC number. FDA is unusually blunt about what that means: 'Inclusion in the NDC Directory does not indicate that FDA has verified the information provided or that the products are FDA-approved… Assignment of an NDC number does not in any way denote FDA approval of the product. Any representation that creates an impression of FDA approval because a product has an NDC number is misleading and violates federal law.' FDA also describes the directory as covering 'approved and unapproved drugs'. A supplier with an NDC has registered and listed a product; nobody has approved it.
National Drug Code Directory — FDA, 4 March 2026“Inclusion in the NDC Directory does not indicate that FDA has verified the information provided or that the products are FDA-approved. The content of each NDC Directory entry is the responsibility of the labeler submitting the SPL file. Assignment of an NDC number does not in any way denote FDA approval of the product. Any representation that creates an impression of FDA approval because a product has an NDC number is misleading and violates federal law.”
Checked against the source on .- Can a compounding pharmacy legally make LL-37?
Not under section 503A. Cathelicidin LL-37 is not on FDA's 503A bulk drug substances list — it appears in none of Categories 1, 2 or 3 of the list updated 14 May 2026, verified by extracting that document directly — and it is not an active ingredient in any FDA-approved drug product. The history is the part that gets reported backwards. Cathelicidin LL-37 was nominated, and FDA placed it in category 2, the category for bulk drug substances that may present significant safety risks. It then left category 2, and it left for one reason: FDA lists it in a table headed 'Bulk drug substances nominated but withdrawn', which FDA describes as substances 'previously in category 2 of the interim policies' that 'were withdrawn by the nominators'. A nominator giving up is not FDA changing its mind. LL-37 did not move into Category 1, it did not reach the bulks list, and FDA left its safety concerns about it published on the same page that records the withdrawal.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — FDA, 22 April 2026“Bulk drug substances nominated but withdrawn — This list of bulk drug substances previously in category 2 of the interim policies were withdrawn by the nominators. … Cathelicidin LL-37”
Checked against the source on .- Is there human evidence that LL-37 works?
There is human evidence, and the largest trial of it did not succeed. HEAL LL-37 (EudraCT 2018-000536-10) was a phase IIb double-blind randomised placebo-controlled study run by Promore Pharma AB in 148 patients with hard-to-heal venous leg ulcers, testing a topical LL-37 formulation alongside compression therapy. The investigators reported: 'Efficacy analysis performed on the full study population did not identify any significant improvement in healing in patients treated with LL-37 as compared with the placebo.' A positive result was reported, but the authors describe it as a POST HOC analysis restricted to the subgroup with large target wounds, and their own conclusion calls for 'a further study adequately powered to statistically assess the treatment outcome in this patient group'. That confirmatory study was never run. Read the scope before carrying any of this across. This trial studied a topical formulation applied to open leg ulcers under compression bandaging. It is not evidence about injected or nasal LL-37, and it says nothing about immune support, gut health, chronic infection or biofilm, which are the uses LL-37 is marketed for.
Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trial (Mahlapuu et al., Wound Repair and Regeneration 2021;29(6):938-950) — PubMed Central, 23 October 2021“Efficacy analysis performed on the full study population did not identify any significant improvement in healing in patients treated with LL-37 as compared with the placebo. In contrast, a post hoc analysis revealed statistically significant improvement with LL-37 treatment in several interrelated healing parameters in the subgroup of patients with large target wounds …”
Checked against the source on .- Has LL-37 ever actually been given to people, or do the studies just measure it in the body?
Both — and separating the two is the single most important thing to get right about this compound. LL-37 is endogenous: it is already present in human neutrophils, epithelia, saliva and wound fluid, so a study can carry 'LL-37' in its title while administering nothing at all. Of the 20 studies ClinicalTrials.gov returns for an LL-37 intervention query, checked one by one on 2 August 2026, eighteen measure endogenous LL-37 as a biomarker — in saliva, serum, gingival crevicular fluid or peri-implant sulcus fluid — most often as a readout of vitamin D supplementation, smoking exposure or gum disease. Those are not trials of a drug. Genuine administration studies do exist, and the earliest is a first-in-man trial published in 2014: Grönberg and colleagues randomised 34 participants with hard-to-heal venous leg ulcers to topical LL-37 or placebo, sponsored by Pergamum AB, and reported 'There were no safety concerns regarding local or systemic adverse events.' A larger phase IIb followed in 148 patients, and separately M.D. Anderson Cancer Center with the National Cancer Institute injected LL-37 directly into melanoma lesions in a phase 1/2 study that completed with 4 participants enrolled (NCT02225366). So the honest count is small but not zero. What none of these studies did is administer LL-37 by the routes it is sold for, or for the reasons it is sold.
Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial (Grönberg et al., Wound Repair and Regeneration 2014;22(5):613-21) — PubMed, 1 September 2014“This first-in-man trial included 34 participants with VLUs … There were no safety concerns regarding local or systemic adverse events. In conclusion, topical treatment with LL-37 for chronic leg ulcers was safe and well tolerated with the marked effect on healing predictors … warranting further investigations.”
Checked against the source on .- Did FDA's July 2026 advisory committee vote cover LL-37?
No. Cathelicidin LL-37 was not among the substances before the Pharmacy Compounding Advisory Committee at its meeting of 23-24 July 2026. The seven bulk drug substances on that agenda were BPC-157, KPV, TB-500, MOTS-c, semax, epitalon and emideltide (DSIP); extracting the agenda document returns no mention of LL-37 or cathelicidin anywhere in it. LL-37 therefore received no recommendation at that meeting, favourable or unfavourable, and nothing about its position changed in July 2026. This is worth stating explicitly because coverage of that meeting is being read across the whole peptide category. Two separate things would have to be true for it to reach LL-37, and neither is: LL-37 was not on the agenda, and in any case an advisory committee recommendation is not a rule — FDA's own description is that advisory committees make non-binding recommendations which the agency generally follows but is not legally bound to follow.
Pharmacy Compounding Advisory Committee Meeting, July 23-24, 2026 — Agenda — FDA, 23 July 2026Checked against the source on .- Is LL-37 safe?
Unknown, and FDA has said so in terms while also publishing two specific concerns. On the general question FDA states that it 'lacks sufficient safety-related information regarding cathelicidin LL-37 to know whether the drug would cause harm when administered to humans', and that compounded drugs containing it 'may pose risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and API characterization'. More specifically, FDA states that 'Nonclinical research findings suggest detrimental effects on male reproduction and that this drug can be protumorigenic in some tissues.' That sentence is written for LL-37 alone rather than shared with the other entries on FDA's page, and it is nonclinical — it describes laboratory and animal findings, not an observed effect in a person. There is genuine human tolerability data, and it is narrow: investigators in two European trials of a TOPICAL formulation applied to venous leg ulcers reported it was well tolerated, with the 2014 trial reporting no safety concerns regarding local or systemic adverse events. That is a finding about a wound preparation on skin, and it does not transfer to an injected or nasal product. The intuition to distrust here is the one this compound invites: LL-37 is a peptide the human body already makes, which is widely treated as meaning it must be harmless. Endogenous is not the same as safe at an administered exposure by an unstudied route, and FDA's published concerns run in the opposite direction.
Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — FDA, 22 April 2026“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.”
Checked against the source on .