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LL-37 5 mg
Peptide Library · Profile
LL-37 5 mg
LL-37 is the only peptide in this library that is already inside the person reading about it — your own neutrophils and skin make it. So the question was never whether it does anything. It is whether more of it helps, and the literature answers that in both directions: three randomised trials, all topical, the largest of which failed its primary endpoint, against a body of work showing this same molecule causes the inflammation in rosacea and breaks immune tolerance to your own DNA in psoriasis and lupus.
Molecular weight4,493.3Da · free peptide · 37 residues
Randomised human trialsThreeall topical · none systemic
Human pharmacokineticsNone foundby any route, in any trial
Gap, antibacterial to cytotoxic2.6–5×5 µM kills E. coli; 13–25 µM kills human cells
The short version
Plain English first. Everything below this section is the same material with the sources, the numbers and the caveats attached.
What it is
A 37-residue fragment of your own cathelicidin protein — the only cathelicidin humans have. Neutrophils carry it, injured skin makes more of it within hours, and it does two jobs at once: it punches holes in bacterial membranes, and it signals to your immune system. Both jobs are real. Neither is gentle.
What has actually been measured
Three randomised, placebo-controlled trials in humans, all of them creams on chronic wounds. The two that report their size enrolled 148 and 34 patients. The 148-patient study — the only properly powered one — found no significant benefit on its primary endpoint. The 34-patient study found benefit at its two lower concentrations and nothing at all at its highest, which is the opposite shape of a normal dose–response.
What has not been measured
Anything systemic. No pharmacokinetic study of administered LL-37 in humans was found by any route — no blood level, no half-life, no clearance. Every human trial on record put it on the surface of a wound and left it there. There is no trial of an injection, and no human safety data for one.
What most people get wrong
Treating “your body makes it” as a safety argument. Your body makes it locally, briefly, and under control. When that control fails, this molecule is the cause of the disease: deleting the cathelicidin gene in mice abolishes rosacea-type skin inflammation, and LL-37 bound to your own DNA is what makes immune cells attack it in psoriasis and lupus. “Endogenous” and “safe to add more of” are not the same claim.
What LL-37 is
A single 37-amino-acid chain, cut out of a larger protein you already carry. The name is literal: two leucines at the start, thirty-seven residues long.
| Sequence | LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES |
| Length | 37 residues |
| Molecular weight | 4,493.3 Da — average mass of the free peptide |
| Net charge near pH 7.4 | about +6 — eleven lysines and arginines against five acidic residues |
| Parent protein | hCAP18, the product of the CAMP gene |
| Structure in water | Disordered. It only becomes a helix once certain anions are present |
The molecular weight above is our own calculation from the published sequence, using standard average residue masses, not a figure copied from a vendor page. We did that because vendor-published weights for this peptide vary, and because the number you actually want depends on the salt form — see below.
Four names for the same thing, and one that means something else
| Name | What it refers to |
|---|---|
| LL-37 | The 37-residue active peptide. This is what is in the vial |
| hCAP18 | The whole parent protein, not the peptide. Papers measuring “hCAP18 expression” are measuring the precursor |
| CAMP | The gene. Mouse knockouts are written Camp−/− |
| Cathelicidin | The family. In humans the family has exactly one member, so “cathelicidin” and “LL-37” get used interchangeably — but in mouse papers “cathelicidin” means CRAMP, a different sequence |
That last row matters more than it looks. A great deal of the animal literature is about CRAMP, the mouse peptide, and is written as though it were about cathelicidin generally. The mouse molecule is not this molecule.
The counterion arithmetic, and why it is the opposite problem to a tripeptide
No vendor we checked discloses the salt form. LL-37 is a strongly basic peptide — six lysines, five arginines and a free N-terminus, twelve sites that can each hold an acid counterion. Trifluoroacetate, the residue left behind by standard purification, weighs 114 Da:
| Form | Peptide content | In a nominal 5 mg vial |
|---|---|---|
| Free peptide | 100% | 5.00 mg |
| 1 TFA | 97.5% | 4.88 mg |
| 6 TFA | 86.8% | 4.34 mg |
| 12 TFA | 76.7% | 3.83 mg |
Compare our Cartalax profile, where a single TFA costs 25.5% of the mass because the molecule is only 333 Da. Here each counterion costs just 2.5% — but there are up to twelve of them. The two peptides arrive at nearly the same worst case, 77% versus 75% peptide content, by completely opposite routes. On a tripeptide the risk is one heavy counterion; on LL-37 it is twelve light ones. Either way, nothing on the label tells you which you have.
Our arithmetic from the published sequence, not a finding from any source. Twelve is the maximum; real material typically carries fewer. The honest statement is that the number is unknown and the range is wide enough to matter.
Vendors disagree about solubility by roughly fifty-fold
We found published solubility figures for this peptide that differ by about fifty times, from the same class of supplier, with no counterion disclosed by either. That is not a small discrepancy in a handling note; it is the difference between a peptide that dissolves readily and one that needs help.
We are not printing either number, because we cannot tell which product each describes. A solubility figure for a TFA salt and a solubility figure for an acetate salt are figures about two different materials, and with the counterion undisclosed neither can be checked.
The human evidence, trial by trial
This is the strongest human dossier of any Khavinson-adjacent or research-only compound in this library — three randomised, placebo-controlled trials. It is also a dossier where the biggest and best-powered study came back negative, and saying so is the whole point of a page like this.
| Trial | Design | Result on the stated primary endpoint |
|---|---|---|
| HEAL LL-37 2021 · venous leg ulcers | 148 patients, phase IIb, double-blind, three arms (two concentrations + placebo), on top of compression therapy | Negative. “Efficacy analysis performed on the full study population did not identify any significant improvement.” A benefit appeared only in a post hoc subgroup of large wounds |
| Grönberg 2014 · venous leg ulcers | 34 patients, first-in-man, three concentrations + placebo, 4-week treatment phase | Mixed. Healing rate about sixfold higher than placebo at the lowest concentration (p = 0.003); at the highest concentration, no difference from placebo at all |
| Diabetic foot ulcer 2023 · Jakarta | Randomised, double-blind, placebo cream, 4 weeks. Enrolment not stated in the abstract | Partially positive. Granulation index consistently better (p = 0.031 to 0.009 across visits), but no reduction in IL-1α, TNF-α or bacterial colonisation — the three mechanisms it was supposed to work through |
The inverted dose–response is the most important thing here
In the 34-patient trial, the two lower concentrations worked and the highest did nothing. In the 148-patient trial, the whole population showed nothing. Read together, those two results say something specific: whatever this peptide does to a wound, it is not a case of more being better, and nobody has established where the useful window is.
That is consistent with the cytotoxicity data further down this page, and it is the single strongest argument against reasoning from “it is antimicrobial, so more of it is more antimicrobial.”
What none of the three trials did
- None gave it systemically. All three were creams or topical applications. There is no injection trial.
- None measured a blood level. No trial we found reports plasma concentration, half-life or clearance for administered LL-37, in humans, by any route.
- None ran longer than four weeks of treatment. There is no long-term human exposure data.
- None was in a healthy person. Every participant had a chronic wound.
A fourth human study exists and is often miscounted as a fourth trial of the peptide: a controlled trial of topical calcipotriol, a vitamin D analogue, which raised the body's own hCAP18 expression in wounded skin. That is a study of a different drug, measuring this peptide as an outcome. It tells you the gene is inducible; it tells you nothing about applying the peptide.
How it works, and the fact that undercuts systemic use
Two mechanisms, both well documented: direct membrane disruption, and immune signalling. The problem is that the best-characterised measurement of the first one also contains a finding nobody selling this peptide quotes.
The direct antimicrobial numbers
| Minimum inhibitory concentration | 5 µM against E. coli |
| Cytotoxic to human cells | 13–25 µM — “cytotoxic against several eukaryotic cells” |
| Separation between the two | about 2.6 to 5-fold |
| Shape required for activity | α-helix. Disordered in plain water; needs bicarbonate, sulfate or trifluoroacetate to fold |
| Below pH 5 | Helicity falls away; at pH 2 it is entirely disordered, and inactive |
In human serum, both activities are switched off
From the same 1998 study that produced every number in the table above, stated plainly by its authors: in the presence of human serum, the antibacterial and the cytotoxic activities of LL-37 are inhibited.
That single sentence is the most consequential thing on this page for anyone reasoning about a systemic route. The peptide's measured potency is a potency in buffer. Put it in serum — which is what you do the moment anything is absorbed — and the authors who established the potency report that it goes away. Serum proteins bind it; apolipoproteins in particular have been implicated. No study we found measures what fraction of an administered dose stays free.
The same paper notes that in solutions matching plasma, intracellular fluid or interstitial fluid, LL-37 is helical — and therefore, in its authors' words, could pose a danger to human cells on release. Both halves of that are in the one source: dangerous by ion composition, neutralised by serum protein. We are reporting both rather than the convenient half.
The immune signalling half
Independent of killing anything, LL-37 is a signalling molecule. It recruits neutrophils, monocytes and T cells, drives keratinocyte migration and angiogenesis, and binds nucleic acids. The wound-healing rationale rests on this half, not on the antimicrobial half — which is consistent with the 2023 diabetic-foot trial, where granulation improved while bacterial counts did not.
It is also where the trouble is.
The part the marketing leaves out
LL-37 is not a molecule with a side-effect list. It is a molecule that is causally implicated in three human diseases, in work published in Nature, Nature Medicine and Science Translational Medicine. This is better-evidenced than most of what is claimed for it.
Rosacea: deleting the gene abolishes the inflammation
People with rosacea express abnormally high levels of cathelicidin in facial skin, and the fragments they express are differently processed from those in unaffected people. Injecting those rosacea-type fragments into mouse skin produces inflammation. Adding the processing enzyme produces inflammation. And the causal step: in mice with the cathelicidin gene deleted, the inflammation does not occur.
That is not a correlation. Nature Medicine, 2007. The molecule is the mechanism of the disease.
Psoriasis: it is what breaks tolerance to your own DNA
Immune cells normally ignore your own DNA. LL-37 binds that DNA and condenses it into aggregates that get delivered into plasmacytoid dendritic cells and retained there, where they trigger TLR9 and a type I interferon response.
The authors' own framing: an endogenous antimicrobial peptide breaking innate tolerance to self-DNA. Nature, 2007.
Lupus: the same complexes, in serum, with antibodies against them
In systemic lupus erythematosus, activated neutrophils release webs of DNA bound to antimicrobial peptides. Those complexes activate the same dendritic-cell pathway — and patients develop autoantibodies against the antimicrobial peptides themselves, which then drives more release. A self-sustaining loop. Science Translational Medicine, 2011.
We are not claiming that applying this peptide causes lupus. We are stating that the molecule's role in a serious autoimmune disease is established in a top-tier journal, and that no study has assessed whether administering it raises autoimmune risk — searched and not found.
Cancer: it goes both ways, by tissue
The oncology literature on LL-37 does not resolve into a direction, and anyone telling you it does in either direction is picking a subset. Review-level summaries describe it as having both pro-tumour and anti-neoplastic properties — promoting invasion in some tissues, cytotoxic to cancer cells in others, with the authors of those reviews explicitly calling the observations inconsistent.
We are deliberately not building a table of which cancer goes which way. The honest summary is that the direction is tissue-dependent and contested in the review literature, and that no human outcome data exists either way. A page that resolved this cleanly would be misrepresenting the field.
One more thing the gene tells you
The same gene is under-expressed in atopic eczema, where low cathelicidin is associated with greater susceptibility to skin infection. So the body appears to have a window: too little is a problem, too much is a different problem. Nothing in the literature establishes where in that window a person is, or how adding more moves them.
Reconstitution and the concentration nobody mentions
The handling question here is unusual, and it is arithmetic rather than opinion: a reconstituted vial of LL-37 sits far above the concentration at which this peptide is cytotoxic in a dish.
| 5 mg in 1 mL | about 1,100 µM |
| 5 mg in 2 mL | about 560 µM |
| Against the E. coli MIC of 5 µM | roughly 220-fold higher at 1 mL |
| Against the 13–25 µM cytotoxic range | roughly 45 to 85-fold higher |
Our arithmetic, from the molecular weight on this page and the published MIC. It is not a dosing calculation and must not be read as one — a concentration in a vial is not a concentration at a tissue, and the serum-binding finding above means the two are not simply related. What it does establish is that undiluted vial concentration is nowhere near the concentrations at which this peptide has been characterised, in either direction.
The anion problem is specific to this peptide
Most peptides in this library are indifferent to what you dissolve them in, within reason. LL-37 is not: it is disordered and inactive in plain water and requires certain anions to adopt the helix its activity depends on. Bicarbonate, sulfate and trifluoroacetate all do it with about equal efficiency; chloride does it less well, even at physiological concentration.
That is a published structural finding, and it has an awkward consequence worth stating: a residual TFA counterion is one of the anions that folds this peptide. The same impurity that costs you mass may be the thing holding the molecule in its active shape. We have found no study that resolves this, and we are not going to pretend otherwise. It is also why acidic conditions matter — below pH 5 the helix comes apart, and at pH 2 it is gone entirely.
The 28-day figure, as always
No stability study specific to this peptide was found — not in solution, not lyophilised, at any temperature. Our storage guide recommends 28 days for a reconstituted peptide in bacteriostatic water. The sterility half of that figure transfers here unchanged; benzyl alcohol does not care what is dissolved in it. The stability half has never been measured for this molecule.
The 28 days is always recommended, never a deadline, and on this compound it carries no compound-specific evidence at all. A 37-residue chain with multiple oxidisable and cleavable positions is a different stability proposition from a tripeptide, and nobody has published the work.
Storage
No storage study specific to LL-37 was found in a primary source. The guidance available is generic peptide handling: freeze the lyophilised solid, keep it dry and dark, avoid repeated freeze–thaw once in solution.
Our general conventions are in the storage guide. We would add one peptide-specific caution from the structural literature rather than from a stability study: because activity depends on helix content, and helix content depends on the ion environment and pH, a solution that has been diluted into something unbuffered may be inactive without looking any different. That is an inference from published structure, flagged as an inference.
Reported effects
The topical safety record is genuinely reassuring and we will say so. There is no systemic safety record at all.
What the trials reported
The 34-patient first-in-man study found no safety concerns regarding local or systemic adverse events across three concentrations. The 148-patient study reported the drug well tolerated and safe at both dose strengths. That is real, prospectively collected human safety data, and it is more than almost anything else in this library has.
It is safety data for a cream on a leg ulcer, for four weeks. It does not extend to any other route, any longer duration, or any healthy person.
The in-vitro number that defines the margin
At 13–25 µM this peptide is cytotoxic to several kinds of human cell, against a 5 µM concentration needed to inhibit E. coli. A two-and-a-half to five-fold window between “kills bacteria” and “kills your cells” is narrow for a molecule, and it is the most likely explanation for the inverted dose–response in the trial where the highest concentration did nothing.
Immunogenicity, which is the regulator's stated concern
FDA's own recorded concern about this substance, verbatim: compounded drugs containing cathelicidin LL-37 “may pose risk for immunogenicity for certain routes of administration.”
Read that against the lupus finding above, where patients develop autoantibodies against the antimicrobial peptides in their own neutrophil traps. The regulator's concern and the published immunology point at the same thing from different directions. No immunogenicity assessment of administered LL-37 has been published that we could find — searched and not found. The concern is on the record; the data is not.
Nobody has opened a vial
We found no published analysis of the contents of research LL-37 vials sold online — no mass spectrometry, no purity audit, by any regulator, academic group or independent laboratory. For a 37-residue synthetic peptide this matters more than for a tripeptide: truncated and deletion products are a known synthesis problem on chains this length, and the structural literature shows that N-terminal deletions of four and eight residues are measurably less active than the full peptide. A truncation here is not an inert impurity; it is a weaker molecule that will pass a crude purity check.
That is an argument for lot-specific certificates with a mass spectrum, not against them. Ours are on the certificate register.
Regulatory status
Unlike most of this library, LL-37 is named explicitly by both the Canadian and American authorities. There is no obscurity defence available here.
| Body | LL-37 named? | What it says |
|---|---|---|
| Health Canada, 1 Aug 2025 | Yes — by name | Listed among unauthorised injectable peptide drugs seized from a Canadian seller. Pinealon is on the same list |
| FDA, updated 22 Apr 2026 | Yes — as “Cathelicidin LL-37” | Nominated for compounding, then withdrawn. Stated concern: may pose risk for immunogenicity for certain routes of administration |
| Approved medicine anywhere | No | The furthest it has reached is a phase IIb trial that missed its primary endpoint. There is no marketing authorisation in any jurisdiction |
| WADA 2026 Prohibited List | Not named — S0 applies | S0 covers substances with no current approval by any governmental regulatory health authority for human therapeutic use. That is this compound exactly |
| Australia | Not checked. We make no claim | |
Two things follow that are worth being blunt about. Being named on the FDA's withdrawn list is not the same as being banned — it means a compounding nomination was made and did not survive, and the reason given was immunogenicity. And being on Health Canada's seizure list means it is an unauthorised drug in Canada, full stop, regardless of what it is called or who sells it. Neither of those is a safety verdict. Both are facts about its legal position, and they are more specific than for almost anything else we stock.
Sentient Biogenix supplies LL-37 for laboratory research use only. It is not for human or veterinary use.
Questions we actually get
What is it?
A 37-residue peptide cut from hCAP18, the only cathelicidin protein humans have. Your neutrophils carry it; injured skin makes more within hours. It kills bacteria directly by disrupting membranes, and it signals to the immune system. Both are well established.
My body already makes it, so it must be safe to add more — right?
That is the inference we would most like to head off. Your body makes it locally, briefly, and under tight control. The best-evidenced thing in the whole literature is what happens when that control fails: deleting the gene in mice abolishes rosacea-type inflammation, meaning the molecule is the cause of it. In psoriasis and lupus, this peptide bound to your own DNA is what makes the immune system attack that DNA. Endogenous does not mean innocuous.
Does it heal wounds?
It has three randomised placebo-controlled trials in chronic wounds, which is more human evidence than most research peptides will ever have. The largest, at 148 patients, did not find a significant benefit in the full population — only in a post hoc subgroup of large wounds. A 34-patient study found clear benefit at its lowest concentration and none at its highest. So: plausibly yes, topically, in a window nobody has pinned down.
Why would the highest dose work worst?
The likeliest reason is on this page. The concentration that kills E. coli is 5 µM; the concentration that kills human cells is 13–25 µM. That is a window of about three to five-fold. Push past it and you are damaging the tissue you are trying to heal.
What's the half-life?
Unknown. No pharmacokinetic study of administered LL-37 in humans was found, by any route. All three trials were topical and none reports a blood level. There is a related and more awkward finding: the study that established this peptide's potency also found that human serum inhibits both its antibacterial and its cytotoxic activity, so even a measured blood concentration would not tell you how much was active.
Is it approved anywhere?
No. The furthest it got was a phase IIb trial that missed its primary endpoint. FDA holds it as a compounding nomination that was withdrawn, with immunogenicity as the stated concern, and Health Canada names it on a 2025 seizure list of unauthorised injectable peptides.
Is the mouse research about this molecule?
Mostly not, and this trips up a lot of summaries. The mouse cathelicidin is CRAMP, a different sequence. Papers titled “cathelicidin” in mice are about CRAMP. The one place that distinction works for the evidence is the rosacea study, where deleting the mouse gene abolished the inflammation — a gene-deletion result does not depend on the sequences matching.
So why do you sell it?
Because it is a legitimate and genuinely interesting research compound with real human trial data behind it — which is rare here. What we will not do is sell it as a safe antimicrobial because your body makes it. The same molecule, in the same literature, causes rosacea and breaks tolerance to self-DNA. You should know both halves before you buy anything from us.
References
- Mahlapuu M, Sidorowicz A, Mikosinski J, et al. Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: a multicentric prospective randomized placebo-controlled clinical trial. Wound Repair and Regeneration 2021;29(6):938–950. DOI 10.1111/wrr.12977. PMID 34687253. — the HEAL LL-37 phase IIb trial, 148 patients. The primary efficacy analysis was negative in its own words: no significant improvement in the full study population. The positive finding is a post hoc subgroup of wounds of at least 10 cm², which the authors themselves say needs a further adequately powered study.
- Grönberg A, Mahlapuu M, Ståhle M, Whately-Smith C, Rollman O. Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial. Wound Repair and Regeneration 2014;22(5):613–21. DOI 10.1111/wrr.12211. PMID 25041740. — first-in-man, 34 patients, three concentrations. Source of the inverted dose–response: about sixfold faster healing at the lowest concentration (p = 0.003), and no difference from placebo at the highest. Also the source of the topical safety statement.
- Miranda E, Bramono K, Yunir E, et al. Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trial. Archives of Dermatological Research 2023;315(9):2623–2633. DOI 10.1007/s00403-023-02657-8. PMID 37480520. Registered NCT04098562. — granulation index better at every visit, but no reduction in IL-1α, TNF-α or aerobic bacterial colonisation. The abstract does not state the number enrolled, so we do not print one.
- Johansson J, Gudmundsson GH, Rottenberg ME, Berndt KD, Agerberth B. Conformation-dependent antibacterial activity of the naturally occurring human peptide LL-37. Journal of Biological Chemistry 1998;273(6):3718–24. DOI 10.1074/jbc.273.6.3718. PMID 9452503. — the single most important source on this page. Origin of the 5 µM E. coli MIC, the 13–25 µM eukaryotic cytotoxicity, the anion-dependent helix, the pH behaviour, the reduced activity of N-terminally truncated forms, and the finding that human serum inhibits both the antibacterial and the cytotoxic activity.
- Yamasaki K, Di Nardo A, Bardan A, et al. Increased serine protease activity and cathelicidin promotes skin inflammation in rosacea. Nature Medicine 2007;13(8):975–80. DOI 10.1038/nm1616. PMID 17676051. — the causal rosacea result. Abnormally high cathelicidin in affected skin, differently processed fragments, inflammation reproduced by injecting those fragments — and abolished in mice with the Camp gene deleted.
- Lande R, Gregorio J, Facchinetti V, et al. Plasmacytoid dendritic cells sense self-DNA coupled with antimicrobial peptide. Nature 2007;449(7162):564–9. DOI 10.1038/nature06116. PMID 17873860. — the psoriasis mechanism. LL-37 condenses inert self-DNA into aggregates retained in early endosomes, triggering TLR9 and interferon. The authors' framing is “breaking innate tolerance to self-DNA.”
- Lande R, Ganguly D, Facchinetti V, et al. Neutrophils activate plasmacytoid dendritic cells by releasing self-DNA-peptide complexes in systemic lupus erythematosus. Science Translational Medicine 2011;3(73):73ra19. DOI 10.1126/scitranslmed.3001180. PMID 21389263. — the lupus arm. Source of the autoantibody finding: patients develop antibodies against the antimicrobial peptides themselves, which drives further release. This is the published counterpart to FDA's immunogenicity concern.
- Kiatsurayanon C, Peng G, Niyonsaba F. Opposing roles of antimicrobial peptides in skin cancers. Current Pharmaceutical Design 2022;28(3):248–258. DOI 10.2174/1381612827666211021163318. PMID 34674617. — the basis for our refusal to give cancer a direction. Review-level statement that these peptides have both pro-tumour and anti-neoplastic properties, with the authors calling the observations inconsistent.
- Sun L, Wang W, Xiao W, Yang H. The roles of cathelicidin LL-37 in inflammatory bowel disease. Inflammatory Bowel Diseases 2016;22(8):1986–91. DOI 10.1097/MIB.0000000000000804. PMID 27135484. — read for the opposite-direction case. Describes the role as intricate: overexpressed in ulcerative colitis mucosa, unchanged in Crohn's, with protective effects reported in models. Another reason not to state a direction.
- Schauber J, Ruzicka T, Rupec RA. Cathelicidin LL-37: a central factor in the pathogenesis of inflammatory dermatoses? Der Hautarzt 2008;59(1):72–4. DOI 10.1007/s00105-007-1457-z. PMID 18209993. — German-language review, read via its English abstract. Source of the three-way framing used on this page: decreased in atopic eczema, overabundant in rosacea, DNA-bound and autoimmune in psoriasis.
- Heilborn JD, Weber G, Grönberg A, Dieterich C, Ståhle M. Topical treatment with the vitamin D analogue calcipotriol enhances the upregulation of the antimicrobial protein hCAP18/LL-37 during wounding in human skin in vivo. Experimental Dermatology 2009;19(4):332–8. DOI 10.1111/j.1600-0625.2009.00997.x. PMID 19878298. — included to exclude it. This is a controlled trial of calcipotriol, not of LL-37, measuring the body's own expression as an outcome. It is sometimes miscounted as a fourth trial of the peptide. Note its own negative: in chronic ulcers, mRNA rose but no consistent protein increase was detected.
- Health Canada. Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks. Advisory, 1 August 2025. recalls-rappels.canada.ca — read in full this session. LL-37 appears by name in the affected-products table, alongside 43 others including Pinealon. The table's lead-in is “Unauthorized injectable peptide drugs, including:”, so the list is not exhaustive.
- US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of 22 April 2026. fda.gov — read in full this session. “Cathelicidin LL-37” appears in the nominated-but-withdrawn table, previously category 2, with the stated concern quoted verbatim on this page. Pinealon, EDR and Glu-Asp-Arg do not appear anywhere on that page.
- World Anti-Doping Agency. Prohibited List 2026, section S0. — LL-37 is not named. The application of S0 is ours, using the list's own definition of a substance with no current approval by any governmental regulatory health authority for human therapeutic use.
Listed rather than hidden, what we could not check. Searches for this page were run against PubMed, which was reachable throughout; identifiers and abstracts above come from it, and the DOI links go to the publishers. We could not obtain the enrolment number for the 2023 diabetic foot ulcer trial from its abstract, so no total patient count is printed on this page. We could not find a pharmacokinetic study of administered LL-37 in humans by any route, an immunogenicity assessment of administered LL-37, or any independent analysis of research-grade vials — all three are searched and not found, never does not exist. We did not check Australian regulatory sources and make no claim about them. The molecular weight, net charge and all counterion and concentration figures on this page are our own arithmetic from the published sequence, flagged as such wherever they appear, and no vendor solubility figure is reproduced because the two we found disagree by roughly fiftyfold with no counterion disclosed by either.
For laboratory research use only. Not for human or veterinary use. Nothing on this page is dosing guidance, and no figure here should be read as a recommendation.