Shop by goal

Popular compounds

Research resources

LL-37: Immune / Anti-Inflammatory research guide

Not medical advice. LL-37 is a research compound. This guide does not provide dosing, diagnosis, therapy recommendations, or claims about effects in humans.

What LL-37 is

LL-37 is the only human cathelicidin - a 37-residue amphipathic antimicrobial peptide that punches holes in bacterial membranes while simultaneously acting as an alarmin that orchestrates the innate immune response.

One-paragraph overview from our research datasheet — still scientific, but faster to read than the full mechanism list below.

LL-37 human cathelicidin antimicrobial peptide (37 aa, +6 net charge) disrupts bacterial membranes via amphipathic alpha-helical channel formation and NF-κB modulation.

Research contexts

Peer-reviewed literature typically discusses LL-37 in specific experimental settings. The points below reflect how the scientific community frames this compound—not as health claims, but as the research questions being asked.

Research vs. personal use: Literature describes experiments in controlled lab and animal models. This is distinct from any real-world use; our products are for laboratory research only.

Typical study contexts

Innate immune activation, viral challenge models, or vaccine-adjuvant style experiments in animals.

Thymic peptides and host-defence research are reported in highly controlled preclinical contexts.

Peer-reviewed preclinical work sometimes describes experiments that track whether forms amphipathic tetrameric transmembrane channels disrupting bacterial membrane integrity via electrostatic insertion

Peer-reviewed preclinical work sometimes describes experiments that track whether broad-spectrum antimicrobial activity against Gram-positive, Gram-negative bacteria, fungi, and enveloped viruses

Peer-reviewed preclinical work sometimes describes experiments that track whether inhibits bacterial biofilm formation through membrane disruption at sub-MIC concentrations

Peer-reviewed preclinical work sometimes describes experiments that track whether interacts with intracellular polyanionic targets (DNA, RNA, ribosomes) for secondary bactericidal mechanisms

Why Immune / Anti-Inflammatory research matters

Immune-focused peptides are studied for how they modulate innate responses, viral models, or antimicrobial peptide biology in controlled experiments.

Mechanisms (technical review)

Our datasheet lists mechanistic themes observed in preclinical work. These are research endpoints, not health claims. They help scientists understand and compare pathways.

Forms amphipathic tetrameric transmembrane channels disrupting bacterial membrane integrity via electrostatic insertion

Broad-spectrum antimicrobial activity against Gram-positive, Gram-negative bacteria, fungi, and enveloped viruses

Inhibits bacterial biofilm formation through membrane disruption at sub-MIC concentrations

Interacts with intracellular polyanionic targets (DNA, RNA, ribosomes) for secondary bactericidal mechanisms

Activates FPRL-1, P2X7, and EGFR receptors modulating immune cell chemotaxis and wound healing

Promotes angiogenesis and keratinocyte migration for enhanced wound closure

Lab handling & preparation

Storage requirements: Lyophilised powder: store in freezer (−20 °C). Reconstituted: refrigerate 1–6 °C, away from sunlight. Use within the validated stability window for the specific batch and formulation. · Learn best practices in our detailed storage guide.

Research dosing context: Literature typically discusses 50-200 μg per day · Once daily subcutaneous injection or topical application · MW ~4493 Da, 37 amino acids with net charge +6 from 16 charged residues. Adopts helix-break-helix conformation in membrane environments. Limitations include susceptibility to proteolytic degradation, dose-dependent cytotoxicity, and high production costs. Vitamin D supplementation upregulates endogenous LL-37 production in vivo.

Preparation steps: Follow our detailed reconstitution guide, use the calculator tool for volume confirmation, and always verify purity with the COA reading guide.

Common Questions People Are Asking

What is LL-37 and how does it work?

LL-37 is the only human cathelicidin antimicrobial peptide - a 37-amino-acid, positively charged (net +6) amphipathic helix cleaved from the precursor hCAP-18. Its primary mechanism is physical: it binds the anionic surface of microbial membranes and disrupts them, while also neutralising bacterial endotoxin (LPS) and acting as an alarmin that signals the wider innate immune system. New-U supplies it for laboratory research only.

What does the LL-37 research actually show?

Preclinical and cell-based studies report broad-spectrum antimicrobial activity (Gram-positive and Gram-negative bacteria, fungi, enveloped viruses), inhibition of biofilm formation, and roles in wound healing and immune signalling; its dysregulation is also studied in inflammatory skin disease such as rosacea, psoriasis and atopic dermatitis (Reinholz & Ruzicka et al., 2012). These are research findings in models, not a promise of any effect in humans.

Is LL-37 legal, and is it approved for use?

LL-37 is not an FDA-approved drug; it is sold strictly as a research compound for laboratory use, not for human consumption. It has appeared in early-phase clinical research (for example topical wound-healing studies), but it remains investigational. Legal status varies by jurisdiction, so confirm your local rules before purchasing.

Can bacteria develop resistance to LL-37?

Resistance is much harder to evolve against membrane-targeting peptides than against receptor- or enzyme-targeting antibiotics, because there is no single protein for the pathogen to mutate. Some bacteria modify their outer-membrane charge to reduce electrostatic attraction, but full escape is rare - part of why antimicrobial peptides like LL-37 are such an active research area in the antibiotic-resistance era.

What is the vitamin D connection?

Cathelicidin (CAMP) gene expression is directly regulated by the vitamin D receptor. Calcitriol (the active form of vitamin D) upregulates endogenous LL-37 production, which is one of the mechanisms behind the observed relationship between vitamin D status and susceptibility to respiratory and tuberculosis infections.

Why is LL-37 dose-dependent for cytotoxicity?

Like most amphipathic antimicrobial peptides, LL-37 is selectively toxic to microbial membranes at low concentrations but loses selectivity at high concentrations, affecting host-cell membranes as well. Research protocols need to balance antimicrobial efficacy against host-cell tolerability, which is a general limitation of the class.

How should LL-37 be stored?

Keep the lyophilised powder frozen at −20 °C. After reconstitution with bacteriostatic water, refrigerate at 1-6 °C and protect from light. LL-37 is susceptible to proteolytic degradation, so use reconstituted material promptly and avoid repeated freeze-thaw cycles.

Is this page medical advice? Can I use LL-37 for my health?

No, and no. This article is educational only. We do not provide dosing, medical recommendations, or health claims. Our products are sold strictly for laboratory research, not for personal use of any kind.

Where do I find LL-37 specs, purity certificates and pricing?

Open the shop listing via “View product details.” There you will see batch specs, the Certificate of Analysis (COA), concentration, purity grade, and available SKUs with current pricing.

Related peptide guides

Other compounds researchers often read about alongside LL-37.

TB-500 - companion guide

BPC-157 - companion guide

GHK-Cu - companion guide

Melanotan-2 - companion guide

Scientific sources & further reading

Primary literature and registries for LL-37, plus mainstream coverage of the peptide category. Research use only - not medical advice.

Databases & literature:

PubMed: peer-reviewed literature on LL-37

ClinicalTrials.gov: registered studies on LL-37

LL-37: Wikipedia

Peptides in the news:

WebMD: consumer health reference

BBC News: Health

CNN Health: “Peptides: what to know about the wellness trend”

Sky News: “Can peptides make America healthy again?”

Sky News: “Inside the exploding US peptides craze” (video)

Sky News Australia: “Black market peptide trade explodes as influencers fuel uptick in use”

Sky News Australia: “Backyard peptide boom sparks alarm” (video)

Sky News Australia: “Oprah reveals struggle with shame of weight-loss drugs”

Ready to order? View full product specs

Access concentration, batch info, variants, and current pricing on our shop.

Also known as: LL-37, Cathelicidin, hCAP-18 Active Fragment, Human Cathelicidin Antimicrobial Peptide, CAMP, Cathelicidin LL-37, Antimicrobial Peptide LL-37

Premium research peptides at >99% HPLC-verified purity, third-party tested by Janoshik Analytical with a Certificate of Analysis on every lot. Shipped lab-direct, discreet and cold-chain, worldwide. For laboratory research use only.

Research use only (RUO). All products are sold strictly for laboratory and research purposes — not for human or veterinary consumption. Purchasers must be 21 or older.

Website & business operated by Hilxera Distribution Services LLC. Registered in Wyoming, ID: 2026-001928701.

Research use only — not for human consumption. All products are supplied strictly for laboratory research purposes.