# LL-37 LL-37 is in limbo: it is not approved, and it is on neither FDA list for compounding. No pharmacy may lawfully make it. The evidence grade is limited-human: a few trials put it on skin sores, with mixed results. FDA says it lacks the safety information to know whether it would harm people. Status checked: 2026-10-25. Last verified: 2026-10-26. Primary source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks This page has not been individually reviewed by a clinician. Information, not medical advice. | Fact | Value | Tier | Checked | Source | |---|---|---|---|---| | Also called | Cathelicidin LL-37, Ropocamptide | peer-reviewed | 2026-10-25 | [source](https://pubmed.ncbi.nlm.nih.gov/34687253/) | | Class | antimicrobial | peer-reviewed | 2026-10-25 | [source](https://pubmed.ncbi.nlm.nih.gov/29665030/) | | Regulatory status | limbo | primary | 2026-10-25 | [source](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) | | Status source read | 2026-10-23 | primary | 2026-10-25 | [source](https://www.fda.gov/media/94155/download) | | Evidence grade | limited-human | our assessment | 2026-10-25 | [source](https://peptideindex.ai/methodology#evidence-grade) | ## Name LL-37 Source: https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee ## Summary A chain of 37 amino acids that human skin makes to fight germs. It has been tested on skin sores and injected into skin tumors. Source: https://pubmed.ncbi.nlm.nih.gov/29665030/ ## Short answer LL-37 is in limbo: it is not approved, and it is on neither FDA list for compounding. No pharmacy may lawfully make it. The evidence grade is limited-human: a few trials put it on skin sores, with mixed results. FDA says it lacks the safety information to know whether it would harm people. Source: https://peptideindex.ai/methodology#short-answer ## Known risks - FDA warns that LL-37 given by some routes may set off the immune system. It also warns of impurities from how the peptide is made [^1]. - FDA says tests in animals point to harm to a male's ability to have children [^1]. - FDA says LL-37 may help tumors grow in some tissues. In mice, LL-37 helped ovarian tumors grow [^1] [^17]. - A woman given LL-37 shots into her melanoma grew many wart-like skin growths and a blister. They went away within 2 months after the shots stopped [^14]. - FDA says it does not have enough safety information to know whether LL-37 would harm people [^1]. Source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks ## What nobody knows yet - Nobody knows whether LL-37 would harm people who take it. FDA says it lacks the safety information to judge [^1]. - Nobody knows whether LL-37 helps leg sores heal. The largest trial found no clear benefit across the whole group [^11]. - Scientists do not know why LL-37 seems to feed some cancers and hold back others [^19]. - FDA has not set a date for its committee to meet on LL-37. Its notice does not say which use the committee will review [^4]. - Nobody knows whether LL-37 cream helps foot sores heal for good. The one trial followed people for only 4 weeks [^12]. Source: https://pubmed.ncbi.nlm.nih.gov/34687253/ ## What it is LL-37 is a chain of 37 amino acids that the human body makes [^14]. Amino acids are the building blocks of proteins. LL-37 is part of the skin's first defense against germs [^14]. White blood cells and the lining of some organs make it too [^19]. It kills some germs and also steers the immune system [^19]. FDA calls it cathelicidin LL-37 [^1]. It is part of no FDA-approved drug and has no official US quality standard [^5]. A drug company has tested it as a treatment for leg sores, under the name ropocamptide [^11]. Doctors in one US study injected it into melanoma, a skin cancer [^14] [^15]. Source: https://pubmed.ncbi.nlm.nih.gov/29665030/ ## Where it stands legally LL-37 is in limbo: FDA lists it among the Category 2 substances whose nominations were withdrawn, and it has not added it to Category 1 [^1] [^2]. That is not approval, and it does not make compounding lawful. Checked 23 October 2026. Category 2 is FDA's list of substances that raise significant safety concerns. Category 1 is the list of substances under evaluation, which pharmacies may use while FDA reviews them [^3]. In April 2026, the groups that nominated LL-37 withdrew, so it came off Category 2 [^1] [^7]. Taking a substance off Category 2 does not by itself let pharmacies use it [^8]. FDA says its Pharmacy Compounding Advisory Committee will discuss LL-37 at a meeting before the end of February 2027 [^4] [^9]. FDA has posted no date for that meeting and no review of LL-37 for it [^4]. The committee gives advice only. FDA decides by writing a rule, after public comment [^7] [^20]. Until FDA acts, a pharmacy that makes LL-37 is outside federal law [^3] [^5]. In 2020, FDA warned a compounder that LL-37 was not eligible for compounding [^5]. The same year, that compounding pharmacy pleaded guilty to distributing unapproved new drugs, LL-37 among them [^6]. Source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks ## What the evidence shows The evidence grade is limited-human: three trials in people put LL-37 on skin sores, and their results are mixed [^10] [^11] [^12]. FDA says it lacks the safety information to know whether LL-37 would harm people [^1]. The body makes its own LL-37, and some studies only measure how much of it a person has [^12] [^19]. A level found in the body does not show that taking LL-37 helps. Leg sores: in a 2014 trial, 34 adults with hard-to-heal leg ulcers had LL-37 or a placebo, a dummy treatment, put on the wound [^10]. Two of the three LL-37 groups healed faster than the placebo group [^10]. A larger 2021 trial in 148 adults found no clear benefit over placebo across the whole group [^11]. A later look found a gain in people with large sores, and the authors say a new trial must test that [^11]. People in both trials tolerated LL-37 on the skin well [^10] [^11]. Foot sores: in a 2023 trial in Jakarta, adults with diabetes and mildly infected foot sores used LL-37 cream or a placebo cream [^12] [^13]. New healing tissue grew faster with LL-37, but germs on the wound did not drop more than with placebo [^12]. Shots: one small US study injected LL-37 into melanoma tumors in the skin [^15]. A 2018 report describes a 63-year-old woman whose injected tumors shrank. About 45 days in, she grew many skin growths, which went away after the shots stopped [^14]. Animals and cells: in diabetic mice, LL-37 helped wounds close [^16]. In mice with ovarian tumors, blocking the body's own LL-37 slowed tumor growth [^17]. In lab dishes, LL-37 made human cells grow faster [^18]. A 2010 review says LL-37 seems to feed some cancers and hold back others [^19]. Source: https://pubmed.ncbi.nlm.nih.gov/34687253/ ## Legitimate ways to get it There is no legal way to get LL-37 in the US today [^2] [^5]. No approved drug contains it. A pharmacy may use a substance with no official quality standard only if it is in an approved drug or on the federal list. LL-37 is neither [^3] [^5]. FDA could add it by writing a rule after its committee meets [^4] [^7]. No trial that gives LL-37 is open now. Of the two registry records that give it, one study is complete and the other has an unknown status [^13] [^15]. Any open trial would appear in the trials block below, with the date the official registry was last checked. Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ## How people are getting it anyway This section describes what happens and is not a recommendation. Pharmacies are the one channel for LL-37 that federal records name [^5] [^6]. In 2020, FDA warned a compounder that its LL-37 products did not meet the rules for compounding [^5]. The same year, that compounding pharmacy pleaded guilty to distributing unapproved new drugs, LL-37 among them [^6]. It agreed to give up its 2019 sales of those products [^6]. With a product made outside the rules, nobody checks what is in it the way FDA checks an approved drug. FDA warns that LL-37 products may hold impurities and may set off the immune system [^1]. We found no federal record that names LL-37 sold by websites or clinics, so this page does not describe those channels. Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ## Access routes Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ### None Detail: There is no legal route to LL-37 in the US today. It is in no approved drug, has no official quality standard, and is not on the list pharmacies may use. Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ## Unofficial channels Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ### Compounding outside the rules What it is: Made by a pharmacy from bulk LL-37, which is not on the list of substances pharmacies may use. Legal position: LL-37 has no official quality standard, is in no approved drug and is not on the federal list, so a pharmacy may not compound it under section 503A. (source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020) Documented risks: - FDA warns that compounded LL-37 may set off the immune system for some routes and may hold impurities. (source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) - FDA says it lacks the safety information to know whether LL-37 would harm people. (source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) Enforcement: - 2020-04-01: FDA warning letter to a compounding pharmacy: LL-37 was among bulk substances that made its products ineligible under section 503A. (source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020) - 2020-10-29: US Department of Justice: a Kentucky compounding pharmacy and its owner pleaded guilty to distributing unapproved new drugs, LL-37 among them. (source: https://www.justice.gov/usao-edky/pr/nicholasville-compounding-pharmacy-and-its-owner-plead-guilty-unlawful-distribution) Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ## Recruiting trials Snapshot date: 2026-10-25. A listing is not a recommendation. Trials have strict eligibility rules. Talk to your doctor and read the official record. None in this snapshot. Source: https://clinicaltrials.gov/api/v2/studies?query.intr=ropocamptide&filter.overallStatus=RECRUITING%2CNOT_YET_RECRUITING&pageSize=50&sort=StartDate%3Adesc&countTotal=true&fields=NCTId%2CBriefTitle%2COverallStatus%2CPhase%2CLeadSponsorName%2CStartDate%2CLocationCountry%2CLocationState ## Sources Source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks ### 1. FDA: bulk drug substances that may present significant safety risks, including those withdrawn from Category 2 Type: regulatory Tier: primary Source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks ### 2. FDA: categories of bulk drug substances nominated under section 503A, list updated 14 May 2026 Type: regulatory Tier: primary Source: https://www.fda.gov/media/94155/download ### 3. FDA: bulk drug substances used in compounding under section 503A Type: regulatory Tier: primary Source: https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act ### 4. FDA: Pharmacy Compounding Advisory Committee meeting before the end of February 2027 Type: regulatory Tier: primary Source: https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee ### 5. FDA warning letter to a compounding pharmacy, 1 April 2020 Type: regulatory Tier: primary Source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 ### 6. US Department of Justice: a Kentucky compounding pharmacy pleads guilty to distributing unapproved drugs, 29 October 2020 Type: regulatory Tier: primary Source: https://www.justice.gov/usao-edky/pr/nicholasville-compounding-pharmacy-and-its-owner-plead-guilty-unlawful-distribution ### 7. McDermott Will & Schulte: what the July 2026 committee votes on peptides mean Type: legal-analysis Tier: legal-analysis Source: https://www.mcdermottlaw.com/insights/bulk-list-bound-pcac-backs-majority-of-peptides-in-two-day-public-meeting/ ### 8. Goodwin: FDA signals a possible change in its stance on compounding some peptides Type: legal-analysis Tier: legal-analysis Source: https://www.goodwinlaw.com/en/insights/blogs/2026/05/fda-signals-potentially-evolving-stance-toward-compounding-of-certain-peptides ### 9. Sheppard Mullin: FDA pairs its peptide policy with action against unlawful sellers Type: legal-analysis Tier: legal-analysis Source: https://www.sheppard.com/insights/blogs/fda-balances-peptide-policy-with-enforcement-against-unlawful-peptide-sellers ### 10. LL-37 on hard-to-heal leg ulcers in 34 adults, placebo-controlled, 2014 Type: rct Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/25041740/ ### 11. LL-37 on hard-to-heal leg ulcers in 148 adults, placebo-controlled, 2021 Type: rct Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/34687253/ ### 12. LL-37 cream on diabetic foot ulcers, double-blind, Jakarta, 2023 Type: rct Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/37480520/ ### 13. ClinicalTrials.gov record NCT04098562: LL-37 cream on diabetic foot ulcers Type: reference Tier: primary Source: https://clinicaltrials.gov/study/NCT04098562 ### 14. Skin harm after LL-37 was injected into melanoma: a report of one woman, 2018 Type: human-trial Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/29665030/ ### 15. ClinicalTrials.gov record NCT02225366: LL-37 injected into melanoma Type: reference Tier: primary Source: https://clinicaltrials.gov/study/NCT02225366 ### 16. LL-37 and wound healing in diabetic mice, 2024 Type: animal Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/38423213/ ### 17. LL-37 and ovarian tumor growth in mice, 2009 Type: animal Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/19234121/ ### 18. LL-37 in breast cancer tissue and the growth of human cells in the lab, 2005 Type: in-vitro Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/15609314/ ### 19. Review: the roles of LL-37 in human cancer, 2010 Type: reference Tier: peer-reviewed Source: https://pubmed.ncbi.nlm.nih.gov/20521250/ ### 20. NBC News: FDA panel recommends easing peptide limits despite agency scientists Type: reference Tier: established-news Source: https://www.nbcnews.com/health/health-news/peptides-restrictions-ease-fda-panel-recommend-bpc-157-scientists-rcna588879 Last verified: 2026-10-26. Sources: - https://clinicaltrials.gov/api/v2/studies?query.intr=ropocamptide&filter.overallStatus=RECRUITING%2CNOT_YET_RECRUITING&pageSize=50&sort=StartDate%3Adesc&countTotal=true&fields=NCTId%2CBriefTitle%2COverallStatus%2CPhase%2CLeadSponsorName%2CStartDate%2CLocationCountry%2CLocationState - https://peptideindex.ai/methodology#evidence-grade - https://peptideindex.ai/methodology#short-answer - https://pubmed.ncbi.nlm.nih.gov/29665030/ - https://pubmed.ncbi.nlm.nih.gov/34687253/ - https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee - https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks - https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 - https://www.fda.gov/media/94155/download [^1]: FDA: bulk drug substances that may present significant safety risks, including those withdrawn from Category 2 https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks [^2]: FDA: categories of bulk drug substances nominated under section 503A, list updated 14 May 2026 https://www.fda.gov/media/94155/download [^3]: FDA: bulk drug substances used in compounding under section 503A https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act [^4]: FDA: Pharmacy Compounding Advisory Committee meeting before the end of February 2027 https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/meeting-pharmacy-compounding-advisory-committee [^5]: FDA warning letter to a compounding pharmacy, 1 April 2020 https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/tailor-made-compounding-llc-594743-04012020 [^6]: US Department of Justice: a Kentucky compounding pharmacy pleads guilty to distributing unapproved drugs, 29 October 2020 https://www.justice.gov/usao-edky/pr/nicholasville-compounding-pharmacy-and-its-owner-plead-guilty-unlawful-distribution [^7]: McDermott Will & Schulte: what the July 2026 committee votes on peptides mean https://www.mcdermottlaw.com/insights/bulk-list-bound-pcac-backs-majority-of-peptides-in-two-day-public-meeting/ [^8]: Goodwin: FDA signals a possible change in its stance on compounding some peptides https://www.goodwinlaw.com/en/insights/blogs/2026/05/fda-signals-potentially-evolving-stance-toward-compounding-of-certain-peptides [^9]: Sheppard Mullin: FDA pairs its peptide policy with action against unlawful sellers https://www.sheppard.com/insights/blogs/fda-balances-peptide-policy-with-enforcement-against-unlawful-peptide-sellers [^10]: LL-37 on hard-to-heal leg ulcers in 34 adults, placebo-controlled, 2014 https://pubmed.ncbi.nlm.nih.gov/25041740/ [^11]: LL-37 on hard-to-heal leg ulcers in 148 adults, placebo-controlled, 2021 https://pubmed.ncbi.nlm.nih.gov/34687253/ [^12]: LL-37 cream on diabetic foot ulcers, double-blind, Jakarta, 2023 https://pubmed.ncbi.nlm.nih.gov/37480520/ [^13]: ClinicalTrials.gov record NCT04098562: LL-37 cream on diabetic foot ulcers https://clinicaltrials.gov/study/NCT04098562 [^14]: Skin harm after LL-37 was injected into melanoma: a report of one woman, 2018 https://pubmed.ncbi.nlm.nih.gov/29665030/ [^15]: ClinicalTrials.gov record NCT02225366: LL-37 injected into melanoma https://clinicaltrials.gov/study/NCT02225366 [^16]: LL-37 and wound healing in diabetic mice, 2024 https://pubmed.ncbi.nlm.nih.gov/38423213/ [^17]: LL-37 and ovarian tumor growth in mice, 2009 https://pubmed.ncbi.nlm.nih.gov/19234121/ [^18]: LL-37 in breast cancer tissue and the growth of human cells in the lab, 2005 https://pubmed.ncbi.nlm.nih.gov/15609314/ [^19]: Review: the roles of LL-37 in human cancer, 2010 https://pubmed.ncbi.nlm.nih.gov/20521250/ [^20]: NBC News: FDA panel recommends easing peptide limits despite agency scientists https://www.nbcnews.com/health/health-news/peptides-restrictions-ease-fda-panel-recommend-bpc-157-scientists-rcna588879