The antimicrobial peptide

LL-37

LL-37 is a human cathelicidin — one of the few antimicrobial peptides produced naturally by the body and studied for its interaction with both infection and immune signalling.

Also known as: Cathelicidin

Research context

  • The only human cathelicidin known.
  • Studied in antimicrobial and immune-modulation research.
  • Single 5mg presentation.
Pricing

LL-37

from £17 per vial

StrengthPrice
5mg £17bank £15.30 Buy vial

Bank transfer prices shown under each card price (10% off). Checkout runs on Stripe; bank orders confirm on clearance.

Related compounds

Thymosin Alpha-1KPVGHK-Cu

What LL-37 is

LL-37 is a 37-amino-acid peptide and the only known human member of the cathelicidin family. It is one of the body's own antimicrobial peptides — produced naturally by epithelial cells and neutrophils, and released in response to infection and inflammation. It is unusual among research peptides in that it is genuinely endogenous rather than synthetic: the sequence exists in you already, and the research literature is largely about how its expression and behaviour are regulated.

What makes LL-37 interesting is that it is not purely antimicrobial. It sits at a junction point in the immune system: it disrupts microbial membranes directly, but it also acts on immune signalling, chemotaxis and wound-response pathways. That dual role is exactly why it appears so often in the literature — and exactly why it is described cautiously.

Where LL-37 sits in the catalogue

LL-37 anchors the immune support shelf. It is not interchangeable with the other compounds sold alongside it, and the differences are worth understanding before choosing:

CompoundClass / originVolume of human evidence
LL-37Human cathelicidin (antimicrobial peptide)Limited — extensive lab work, few controlled human studies
Thymosin Alpha-1Thymic peptide; T-cell maturation signallingModerate — used clinically in some countries as an adjunct
KPVTripeptide fragment of α-MSHEarly — animal and in-vitro inflammation models
GHK-CuCopper-binding tripeptide; tissue-remodelling researchModerate — long history of topical research

Thymosin Alpha-1 has the longest clinical history on this shelf. LL-37 has the largest basic-science literature. Neither is a medicine in the way that word is normally used, and neither is sold as one here.

Supply, handling and documentation

LL-37 is supplied as lyophilised powder in a 5mg single presentation. Folding behaviour matters here: LL-37 is a longer, more structurally complex peptide than the tri- and tetrapeptides on our shelf, and it is less forgiving of rough handling.

  • Store sealed vials refrigerated, dry and protected from light.
  • Reconstitute gently — swirl, do not vortex or shake aggressively, as longer peptides are more prone to aggregation.
  • Keep reconstituted solution refrigerated at 2–8°C and covered.
  • Do not refreeze once reconstituted.

Batch documentation is available on request — see the lab and COA policy for what is and is not provided. The reconstitution guide covers gentle handling technique.

Ordering, payment and delivery

Priced per vial in the panel at the top of the page. Bank transfer is 10% below the card price and is shown beneath it; bank orders confirm on clearance. Card checkout is handled by Stripe.

UK dispatch is same or next working day with tracking. Shipping and payment terms are set out on the delivery page. Questions before ordering are welcome — just contact us.

LL-37: common questions

Is LL-37 natural?

Yes. It is the only known human cathelicidin and is produced by the body as part of its innate antimicrobial response. The research peptide supplied here is the same sequence, made synthetically.

Is LL-37 a medicine?

No. It is supplied as a research chemical. It is not a medicine, it is not for human or veterinary use, and nothing on this page is medical advice.

What is LL-37 researched for?

Its antimicrobial action on microbial membranes, and separately its role in immune signalling, chemotaxis and wound-response pathways.

Why is LL-37 described as more difficult to handle?

It is 37 amino acids rather than three or four. Longer chains are more prone to aggregation when agitated, so reconstitution should be gentle and the solution should not be repeatedly frozen.

Do you offer more than one size?

LL-37 is a single 5mg presentation, priced in the table above.

Do you provide a certificate of analysis?

Batch documentation is available on request. See the lab and COA policy for the exact scope.

Research purposes only. LL-37 is supplied as a research chemical. It is not a medicine, it is not for human or veterinary use, and nothing here is medical advice or a dosing recommendation.