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Evidence-rated reference Updated August 2026
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KPV vs LL-37

The distinction that mattersBoth host-derived peptides sold for inflammation, with opposite immune directions. KPV suppresses NF-kB signalling; LL-37 is pro-inflammatory at higher concentrations and drives psoriasis and lupus pathology.

These are not equivalent in evidence LL-37 is rated 2/5 and KPV is rated 1/5 — a gap of 1 level on our scale. Similar marketing does not mean similar proof.

KPV Research Use OnlyLL-37 Research Use Only
Evidence rating
1/5 Minimal Evidence rating 1 out of 5: Minimal
2/5 Limited Evidence rating 2 out of 5: Limited
Regulatory statusNot approved. Preclinical anti-inflammatory research compound; increasingly marketed for gut and skin inflammation.Not approved. Studied topically for chronic wounds; systemic use unstudied. Has a genuine pro-inflammatory disease association.
CategoryImmune & Anti-inflammatoryAntimicrobial & Antibiotic
Drug classC-terminal tripeptide fragment of alpha-melanocyte-stimulating hormoneHuman cathelicidin antimicrobial peptide — 37 residues
RouteOral, topical, or subcutaneous (research)Topical or subcutaneous (research)
Half-lifeNo pharmacokinetic study exists, in humans or animals. As an unmodified tripeptide it is expected to be cleaved rapidly by peptidases.No measured half-life, in humans or animals. Proteases in serum and wound fluid degrade it, which is why analogues are engineered for stability.
Sequence length3 residues37 residues
Molecular weight342.4 Da4,493.3 Da
Studied inRodent colitis models, in-vitro immune cell work, and topical dermatology models. No completed human trials.Small phase 1/2 topical trials in hard-to-heal venous leg ulcers; extensive immunology research; substantial literature on its role in autoimmune skin disease.
Who should avoid it
  • Immunosuppressed patients
  • Pregnancy
  • Active infection
  • Psoriasis, rosacea, or lupus
  • Any autoimmune inflammatory condition
  • Pregnancy
  • Systemic use generally
Legal statusNot approved for human use.Not approved for human use.

Benefits — KPV

  • Anti-inflammatory without pigmentation

    Retains alpha-MSH anti-inflammatory activity while lacking the melanocortin pigmentation effect — a clean pharmacological separation.

  • Colitis improvement in rodents

    Oral and rectal delivery reduce colonic inflammation in animal models of inflammatory bowel disease.

  • Antimicrobial activity in vitro

    Activity against Candida and some bacteria in laboratory models.

  • Favourable preclinical safety

    Small tripeptides with endogenous origins generally show low toxicity in animal work.

Benefits — LL-37

  • Broad-spectrum antimicrobial activity

    Active against bacteria, fungi and some viruses, including biofilm-forming organisms, with a membrane mechanism that resists conventional resistance development.

  • Chronic wound healing signal

    A small randomized topical trial in venous leg ulcers showed improved healing rates.

  • Endotoxin neutralisation

    Binds and neutralises bacterial LPS in laboratory models.

  • Immune cell recruitment

    Chemotactic for neutrophils, monocytes and T cells.

Risks & cons — KPV

  • No human trials

    All efficacy claims are preclinical extrapolation.

  • Immune modulation is not inherently benign

    Suppressing NF-κB signalling long-term has implications for infection surveillance and tumour immunity that have not been studied.

  • Unapproved and unregulated

    Research-chemical supply chain.

  • Delivery and stability poorly characterised

    How much survives oral administration in humans is unknown.

Risks & cons — LL-37

  • Drives autoimmune skin disease

    LL-37 is overexpressed in psoriasis and rosacea lesions and functions as an autoantigen in psoriasis. Adding more is mechanistically the wrong direction in these conditions.

  • Pro-inflammatory at higher concentrations

    The same peptide is antimicrobial at low concentration and inflammatory at high concentration — a narrow therapeutic window.

  • Cytotoxic to human cells at higher doses

    Membrane-disrupting activity is not perfectly selective for microbes.

  • No systemic human data

    Injectable use has never been evaluated.

  • Lupus association

    LL-37-DNA complexes are implicated in systemic lupus erythematosus pathogenesis.

Infographic for KPV
Infographic for LL-37

A comparison is not a recommendation. Neither column is being suggested for you. Which — if either — is appropriate depends on your diagnosis, history and medications, and that is a conversation for a qualified clinician.