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Comparison

KPV vs LL-37

Both are healing & repair, so the meaningful differences are in kinetics, evidence and regulatory status.

On published evidence alone, LL-37 is the better documented of the two (preliminary human). That is a statement about the state of the literature, not a recommendation.

KPV LL-37
Class Healing & repair Healing & repair
Evidence Animal models only Preliminary human
Human trials None published ~3
Half-life ~1-2 hours ~1 hour
Reported range 200-500 mcg 100-500 mcg
Frequency 1-2x daily Once daily, short courses
Routes Oral, Subcutaneous, Topical Subcutaneous, Topical
FDA approved No No
Research use only Yes Yes
Banned in sport No No
Studied for Inflammatory bowel research, Skin inflammation, Gut barrier research Antimicrobial research, Biofilm research, Wound healing
Reported side effects Injection-site reactions, Mild gastrointestinal upset Injection-site inflammation, Flu-like symptoms, Flushing

KPV

KPV is the terminal three residues of alpha-melanocyte-stimulating hormone. It retains the parent hormone anti-inflammatory activity, apparently by entering cells and interfering with NF-κB and MAPK signalling to reduce proinflammatory cytokine production, but it does not activate melanocortin-1 receptors and therefore does not cause tanning. Most research is in inflammatory bowel models, where oral and rectal delivery have been examined.

LL-37

LL-37 is the active 37-residue fragment cleaved from human cathelicidin hCAP18, produced by neutrophils and epithelial cells. It disrupts bacterial membranes directly and also modulates host immunity by recruiting immune cells, neutralising endotoxin and influencing wound repair. Its biology is genuinely double-edged: the same peptide is implicated in the pathology of rosacea and psoriasis, so more is not straightforwardly better.

KPV vs LL-37: common questions

What is the difference between KPV and LL-37?

Both are healing & repair. KPV: The C-terminal tripeptide of alpha-MSH, which keeps the anti-inflammatory activity without the pigmentation effects. LL-37: The only human cathelicidin antimicrobial peptide, with broad antibacterial activity and a complicated immunomodulatory profile.

Which has stronger evidence, KPV or LL-37?

LL-37 has the stronger evidence base (preliminary human, about 3 human studies) compared with KPV (animal models only).

Are KPV and LL-37 FDA approved?

Neither is FDA approved for any indication.

References

Regulatory and primary sources

  1. PubChem compound record (CID 13294447) ↗ · structure, identifiers, synonyms
  2. FDA: Unapproved drugs and "research use only" products ↗ · regulatory status of non-approved products
  3. PubChem compound record (CID 16198951) ↗ · structure, identifiers, synonyms
  4. CAS Registry Number 154947-66-7 ↗ · chemical identity

Published literature

  1. Ichiyama T, Sato S, Okada K, et al.. The neuroimmunomodulatory peptide alpha-MSH.Ann N Y Acad Sci 2000.PubMed 11268347 · doi:10.1111/j.1749-6632.2000.tb05386.x
  2. Coutinho LFD, DE Oliveira Neves LF, Camilo RP. A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review.J Sports Med Phys Fitness 2026.PubMed 41880199 · doi:10.23736/S0022-4707.26.17773-1
  3. Catania A, Cutuli M, Garofalo L, et al.. The neuropeptide alpha-MSH in host defense.Ann N Y Acad Sci 2000.PubMed 11268348 · doi:10.1111/j.1749-6632.2000.tb05387.x
  4. Brzoska T, Böhm M, Lügering A, et al.. Terminal signal: anti-inflammatory effects of α-melanocyte-stimulating hormone related peptides beyond the pharmacophore.Adv Exp Med Biol 2010.PubMed 21222263 · doi:10.1007/978-1-4419-6354-3_8
  5. Adnan SB, Maarof M, Fauzi MB, et al.. Exploring the Role of Tripeptides in Wound Healing and Skin Regeneration: A Comprehensive Review.Int J Med Sci 2025.PubMed 41209547 · doi:10.7150/ijms.118118
  6. Lipton JM, Catania A. Mechanisms of antiinflammatory action of the neuroimmunomodulatory peptide alpha-MSH.Ann N Y Acad Sci 1998.PubMed 9629264 · doi:10.1111/j.1749-6632.1998.tb09576.x
  7. Rodrigues JM, Ferreira Leal AP, Buccini DF, et al.. Host defense peptides as a new drug lead to a strategy for inflammatory bowel disease.Drug Discov Today 2025.PubMed 41241376 · doi:10.1016/j.drudis.2025.104535
  8. Lipton JM, Catania A, Delgado R. Peptide modulation of inflammatory processes within the brain.Neuroimmunomodulation 1998.PubMed 9730684 · doi:10.1159/000026335
  9. Ahn CS, Huang WW. Rosacea Pathogenesis.Dermatol Clin 2018.PubMed 29499802 · doi:10.1016/j.det.2017.11.001
  10. Ismailova A, White JH. Vitamin D, infections and immunity.Rev Endocr Metab Disord 2022.PubMed 34322844 · doi:10.1007/s11154-021-09679-5
  11. Malhotra S, Hayes D Jr, Wozniak DJ. Cystic Fibrosis and Pseudomonas aeruginosa: the Host-Microbe Interface.Clin Microbiol Rev 2019.PubMed 31142499 · doi:10.1128/CMR.00138-18
  12. Wang H, Zhou C. Advances in the pathogenesis of rosacea.Front Immunol 2025.PubMed 41646975 · doi:10.3389/fimmu.2025.1705588
  13. Takahashi T, Yamasaki K. Psoriasis and Antimicrobial Peptides.Int J Mol Sci 2020.PubMed 32947991 · doi:10.3390/ijms21186791
  14. Traidl S, Roesner L, Zeitvogel J, et al.. Eczema herpeticum in atopic dermatitis.Allergy 2021.PubMed 33844308 · doi:10.1111/all.14853
  15. Scheenstra MR, van Harten RM, Veldhuizen EJA, et al.. Cathelicidins Modulate TLR-Activation and Inflammation.Front Immunol 2020.PubMed 32582207 · doi:10.3389/fimmu.2020.01137
  16. Kwiecien K, Zegar A, Jung J, et al.. Architecture of antimicrobial skin defense.Cytokine Growth Factor Rev 2019.PubMed 31473081 · doi:10.1016/j.cytogfr.2019.08.001

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.