LL-37 vs BPC-157
LL-37 is the sole human cathelicidin, a 37-residue antimicrobial and immunomodulatory peptide released from the hCAP18 precursor encoded by the CAMP gene and induced by 1,25-dihydroxyvitamin D3. BPC-157 is a synthetic pentadecapeptide whose sequence corresponds to a fragment of a protein found in gastric juice, with no confirmed endogenous circulating counterpart. Both are promoted for gut and tissue repair, which is why the pair is compared, but they come from opposite ends of the evidence spectrum: LL-37 has completed randomised placebo-controlled human trials, including one that failed its primary analysis, while BPC-157 has a large rodent literature and no controlled human trial at all. No study has administered both. Four publications engage both peptides, all of them reviews that catalogue them alongside other repair or anti-inflammatory peptides, and none of the four generated comparative data.
No study has compared them directly.
Everything below is drawn from separate studies that used different models, endpoints and species. That is a real limit on what can be concluded, not a formality.
No published study has administered LL-37 and BPC-157 in the same experiment, and searches of PubMed and Europe PMC returned no comparison of the two in any species or model. The four publications that engage both are reviews. A 2026 narrative review of therapeutic peptides grouped them in the same section on regenerative and tissue-repair peptides, describing BPC-157 as a gastric-juice-derived pentadecapeptide stable in gastric acid and LL-37 as the only human cathelicidin, with roles in epithelial barrier integrity, intestinal inflammation and wound repair. A 2024 review of bioactive peptides for skin wound repair tabulated both among candidate wound-healing peptides with their sequences and sources. Two further reviews, one on bacteria-based platforms for inflammatory bowel disease and one on bioactive peptides produced by engineered probiotics, listed engineered Lactococcus lactis strains secreting BPC-157 alongside strains secreting cathelicidin, the peptide family to which LL-37 belongs, as separate delivery strategies for colitis. In every case the two peptides are described in parallel rather than measured against each other.
The 4 publications that cover both
- 01Review2026
Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives
Renke G, Chinellato L · Int J Mol Sci · narrative review of 106 articles on therapeutic peptides in metabolic, endocrine and aesthetic practice, with a section on regenerative and tissue-repair peptides
The review placed LL-37 and BPC-157 in the same section on regenerative and tissue-repair peptides. BPC-157 was described as a fifteen-amino-acid peptide originally isolated from human gastric juice with a multimodal mechanism, and its targets were given as injured tendon, muscle, ligament, bone, peripheral nerve and gastrointestinal mucosa on the basis of preclinical evidence. LL-37 was described as the only human cathelicidin, expressed in the gastrointestinal epithelium and contributing to colonic barrier integrity and microbiota balance, with protective roles against colitis and colon tumorigenesis in animal models. The review characterised LL-37 as a promising but experimental therapeutic target and reported no comparison between the two.
- 02Review2024
Discovery of bioactive peptides as therapeutic agents for skin wound repair
Md Fadilah NI, et al. · J Tissue Eng · narrative review of bioactive peptides for skin wound repair, tabulating antimicrobial and tissue-repair peptides from marine, amphibian, mammalian and synthetic sources with their sequences and origins
The review tabulated LL-37, identified as the human cathelicidin with the sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES, and BPC-157, identified as derived from human gastric juice with the sequence GEPPPGKPADDAGLV, among peptides with reported wound-repair activity. It described defensins and cathelicidins as among the best-studied antimicrobial peptide classes with immunomodulatory properties relevant to wound healing, and grouped BPC-157 with peptides drawn from other biological sources. No comparative experiment between the two was reported.
- 03Review2024
Recent advances in bacteria-based platforms for inflammatory bowel diseases treatment
Lu J, et al. · Exploration (Beijing) · narrative review of engineered bacteria used as in situ drug-producing carriers for inflammatory bowel disease, with a table of strains and the therapeutic proteins or peptides they secrete
The review described localised secretion of the gastric pentadecapeptide BPC-157 by genetically engineered probiotics in the colon as an antioxidant strategy for colitis, citing work in which Lactococcus lactis expressing BPC-157 reduced reactive oxygen species in fibroblast cells. Cathelicidin-secreting Lactococcus lactis appeared separately in the same table as a microbial-regulation strategy tested in dextran sodium sulfate colitis in mice. The two were listed as distinct delivery approaches and were not compared.
- 04Review2022
Bioactive peptides produced by engineered probiotics and other food-grade bacteria: A review
Romero-Luna HE, et al. · Food Chem X · narrative review of bioactive peptides produced by engineered probiotics and food-grade bacteria, tabulating antimicrobial, antiviral, antidiabetic, antihypertensive and anti-inflammatory peptides with the strains expressing them
The review listed the pentadecapeptide BPC-157 expressed in Lactococcus lactis, reported to decrease reactive oxygen species concentration in fibroblast cells as a possible approach to inflammatory bowel disease and gastrointestinal inflammation, and listed cathelicidin expressed in a separate Lactococcus lactis strain as reducing inflammation in mice with colitis. Alpha-melanocyte-stimulating hormone delivered by Bifidobacterium longum appeared in the same table. The peptides were catalogued individually with no comparison between them.
Side by side.
| LL-37 | BPC-157 | |
|---|---|---|
| Evidence maturity | Early clinical | Preclinical only |
| Studies cited here | 17 | 15 |
| Published 2023 or later | 13 | 8 |
| Newest paper | 2026 | 2026 |
| Sequence and origin | The only human cathelicidin, a 37-residue amphipathic alpha-helical peptide released by proteolytic cleavage of the hCAP18 precursor encoded by the CAMP gene, expressed by neutrophils, monocytes and epithelial cells and transcriptionally induced by 1,25-dihydroxyvitamin D3. | A synthetic 15-amino-acid peptide whose sequence corresponds to a fragment of a protein found in gastric juice. It has no confirmed endogenous circulating counterpart. |
| Mechanism as described in the literature | Direct membrane permeabilisation of microbes, neutralisation of lipopolysaccharide, and receptor-mediated chemotaxis and immunomodulation through FPR2/FPRL1, with effects that are strongly concentration- and context-dependent. | Angiogenesis associated with VEGFR2 activation and upregulation, modulation of the nitric oxide system, and cytoprotective and gut-barrier effects reported in rodents. |
| Size of the evidence base | Seventeen studies in this library: five human clinical, one systematic review, four animal in vivo, five in vitro and two reviews, spanning 2000 to 2026. | Fifteen studies: eight animal in vivo, three human clinical, two in vitro, one systematic review and one review, spanning 2006 to 2026. |
| Human data | Randomised placebo-controlled trials have been completed, including a phase IIb trial of topical LL-37 in hard-to-heal venous leg ulcers that was negative on its primary analysis, a double-blind trial of an LL-37 cream in mildly infected diabetic foot ulcers, and an open-label randomised trial of an oral recombinant formulation in hospitalised COVID-19 patients. No systemic or injectable human data exist. | Two uncontrolled open-label pilot studies and one retrospective chart review, all from the same private clinic, plus one ex vivo study on surgically discarded human arterial tissue. No randomised controlled trial has been completed for any indication. |
| Best-characterised finding | Chemoattraction of human neutrophils, monocytes and T cells through FPRL1, reported in 2000, and prevention of bacterial biofilm formation at concentrations below those required to kill planktonic bacteria, reported in 2008. | Accelerated healing in rat transection and defect models of quadriceps muscle, medial collateral ligament and the myotendinous junction, alongside gastrointestinal and ischaemia-reperfusion protection. |
| Safety signals reported | Elevated LL-37 is implicated as a pathogenic driver in rosacea, psoriasis and atherosclerosis, and 2026 observational work described an LL-37-ApoB-100 complex as a coronary artery disease biomarker and an adaptive immune response to LL-37 as an autoantigen. The switch between protective and inflammatory behaviour is not adequately characterised. | No long-term human safety data exist and no human pharmacokinetic study has been published; the only disposition data come from a 2022 study in rats and dogs. Orthopaedic reviews published in 2025 and 2026 characterised the human evidence as insufficient. |
| Independence of the literature | Broadly distributed across immunology, dermatology, microbiology, cardiology and ophthalmology groups internationally, with clinical trials run by independent sponsors. | Much of the preclinical corpus originates from a small number of closely affiliated research groups, and all three human reports come from one private clinic, which limits independent replication. |
| Regulatory and anti-doping status | No approved LL-37 product in any jurisdiction, and the controlled human trials used topical or oral formulations rather than injection. | No approved formulation in any jurisdiction, and the peptide is prohibited in professional sport. |
And what it does not.
The two peptides are not comparable in the way the pairing implies. LL-37 is an endogenous human effector with a large mechanistic literature, several completed randomised controlled trials and a documented double role: the same peptide that supports barrier defence and wound repair is implicated as a pathogenic driver in rosacea, psoriasis and atherosclerosis, and its largest wound trial failed its primary analysis. BPC-157 is a synthetic peptide with a much larger volume of rodent work aimed directly at tendon, ligament, muscle and gut injury, no completed randomised controlled trial, limited independent replication and human reports confined to two uncontrolled pilots and one chart review from a single clinic. Neither has controlled human evidence for the soft-tissue and gastrointestinal repair uses that drive the comparison, and no study has ever measured them against each other, so claims that one is more effective than the other are not sourced from data.
Common questions.
- Has a single study given LL-37 and BPC-157 to the same subjects?
No. Searches of PubMed and Europe PMC across peptide names, sequence names and the cathelicidin family term returned no experiment with arms for both, in cell culture, in animals or in humans. The four publications that name both are review articles, which catalogue each peptide separately among wound-repair or anti-inflammatory candidates. Nothing in the literature measures the two under the same conditions, so no comparative ranking can be drawn from published data.
- What did the phase IIb venous leg ulcer trial of LL-37 report?
The HEAL LL-37 trial was a multicentre, double-blind, randomised, placebo-controlled study in 148 patients with hard-to-heal venous leg ulcers, testing a topical formulation. It was negative on its primary analysis, and it remains the largest controlled human trial of the peptide. Two smaller randomised trials have since been published, one of a topical cream in mildly infected diabetic foot ulcers and one of an oral recombinant formulation in hospitalised COVID-19 patients.
- Is either peptide produced naturally in the human body?
LL-37 is. It is the sole human cathelicidin, released by proteolytic cleavage of the hCAP18 precursor encoded by the CAMP gene, expressed by neutrophils, monocytes and epithelial cells, and transcriptionally induced by 1,25-dihydroxyvitamin D3. BPC-157 corresponds to a fragment of a protein found in gastric juice, but no endogenous circulating counterpart of the synthetic pentadecapeptide has been confirmed, so the marketed molecule is a laboratory construct rather than a human peptide.
- Why is LL-37 described as harmful in some conditions?
Its activity is concentration- and context-dependent. The same peptide that permeabilises microbial membranes and chemoattracts immune cells is implicated as a pathogenic driver in rosacea, psoriasis and atherosclerosis. Mouse models of rosacea-like inflammation are induced by injecting LL-37, and 2026 observational studies described an LL-37-ApoB-100 complex as a coronary artery disease biomarker and characterised adaptive immune responses to LL-37 as an autoantigen response in atherosclerotic disease.
- What do the engineered-bacteria reviews show about the two peptides?
They show parallel delivery strategies rather than a comparison. Both reviews tabulate Lactococcus lactis engineered to secrete BPC-157, cited as reducing reactive oxygen species in fibroblast cells, and separately tabulate Lactococcus lactis engineered to secrete cathelicidin, cited as reducing inflammation in mice with dextran sodium sulfate colitis. The strains, the endpoints and the source studies differ, so the tables record two independent lines of work rather than a head-to-head result.
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no comparison here should be read as a recommendation of either compound.