NOT MEDICAL ADVICE

LL-37

Estimated Market Price
$119.99 $134.99
Based on verified supplier pricing for research-grade compounds
Human antimicrobial peptide with broad-spectrum defense against bacteria, viruses, fungi, and biofilms. Supports innate immunity and tissue healing.
How it works

Punches holes in bacterial membranes to kill pathogens directly, while also recruiting immune cells to the site and breaking up stubborn biofilms. Doubles as a wound-healing promoter.

Immune Support

Recovery

What to Expect
Days 1–3 Antimicrobial membrane disruption active; immune recruitment begins. If fighting infection, may notice early improvement.
Week 1–2 Biofilm disruption progressing; wound healing accelerating. Wounds healing faster; skin infections clearing up.
Week 3–4 Immune modulation optimized; infection markers declining. Immune function feels stronger; getting sick less.
Week 5–8 Peak antimicrobial and healing benefits; reassess protocol. Overall immune resilience improved; healing optimized.

Verified Suppliers

For research purposes only. These suppliers have been independently verified by PepSpace. We do not process sales directly.

PepSpace is not affiliated with any listed supplier
Protocol & Dosage
Typical Dosage 50–100 mcg SC daily
Administration Subcutaneous injection
Schedule Once daily
Protocol Duration 4–8 weeks
Half-Life Minutes to hours
Side Effects & Safety
Tolerability Profile Mild

Generally well tolerated; side effects are mild and transient

Common Side Effects

  • Injection site redness or painmost users
  • Mild warmth at injection sitesome users

Less Common

  • Temporary fatigueoccasional
  • Headacheoccasional
  • Mild immune-activation response (transient flu-like feeling)occasional

Discontinue If

  • Severe allergic reaction
  • Signs of autoimmune flare
  • Persistent skin reaction at or beyond injection site

Contraindications

  • Active autoimmune disease
  • Pregnancy or breastfeeding
  • Known hypersensitivity to cathelicidin peptides

Data note: Endogenous antimicrobial peptide. Part of innate immune defense. Limited clinical trial data for exogenous administration.

Always consult a qualified healthcare professional before use. This information is for research reference only and does not constitute medical advice.

Ask about LL-37
Send us a message

Call us
+1 (518) 327-4392
Business hours
Monday – Friday 9:00 AM – 6:00 PM EST
Saturday 10:00 AM – 2:00 PM EST
Sunday Closed

You can also reach us via or .

How to Apply

1

Gather

Peptide vial, BAC water, alcohol swabs, insulin syringe

2

Sanitize

Wipe tops of both vials with alcohol swabs

3

Draw

Pull 1–2 mL of BAC water into syringe

4

Add Water

Release water slowly along vial wall, not directly on powder

5

Swirl

Roll between palms until dissolved. Never shake.

6

Store

Refrigerate 2–8°C, use within 30 days

Frequently Asked Questions

Yes. Bacteriostatic water (BAC water) is required to reconstitute lyophilized (freeze-dried) peptides. It contains 0.9% benzyl alcohol which prevents bacterial growth, keeping your reconstituted peptide safe for multiple uses over up to 30 days.

Unreconstituted: store at -20°C (freezer) for long-term, or 2–8°C (fridge) for short-term. After reconstitution: always refrigerate at 2–8°C and use within 30 days. Keep away from direct sunlight.

Results vary by individual and protocol. In research settings, measurable effects are typically observed within 1–4 weeks depending on the specific peptide, dosage, and application. Consult a qualified professional for guidance.

Verified suppliers typically include a full third-party COA verifying purity (99%+), identity, and sterility. We recommend only sourcing from vendors that provide batch-specific testing data.

We list verified suppliers above that have been independently reviewed for product quality, testing transparency, and shipping reliability. Always verify COA data before sourcing.

Compound Profile

Scientific data & classification for LL-37

Also Known As LL-37, Cathelicidin, hCAP18(134-170), CAMP
Classification Antimicrobial Peptide · Innate Immunity
Sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES (37 aa)
Molecular Formula C₂₀₅H₃₄₀N₆₀O₅₃
Molecular Weight 4,493.33 Da
CAS Number 154947-66-7
Half-Life Minutes to hours
Origin Human cathelicidin antimicrobial peptide - produced by neutrophils, epithelial cells, macrophages
Administration Subcutaneous injection
Status Research compound - clinical trials for wound healing
Mechanism of Action Punches holes in bacterial membranes to kill pathogens directly, while also recruiting immune cells to the site and breaking up stubborn biofilms. Doubles as a wound-healing promoter.
Research Overview LL-37 is the only human cathelicidin antimicrobial peptide, a 37-amino-acid amphipathic alpha-helical peptide released by proteolytic cleavage of the 18 kDa precursor protein hCAP18 (human cationic antimicrobial protein 18) by the serine protease proteinase 3 in neutrophil granules, and by kallikrein-related peptidases in keratinocytes and other epithelial cells. The peptide's name derives from its two N-terminal leucine residues and 37-amino-acid length. LL-37 is expressed in neutrophils, macrophages, monocytes, NK cells, mast cells, and epithelial surfaces of the skin, respiratory tract, gastrointestinal tract, and genitourinary system, positioning it as a critical first-line defense component of the innate immune system. The antimicrobial mechanism involves the peptide's amphipathic alpha-helical structure - the hydrophobic face inserts into microbial membranes while the cationic face interacts with negatively charged phospholipid head groups (phosphatidylglycerol, cardiolipin) that are enriched in bacterial membranes but largely absent from the outer leaflet of mammalian cell membranes. This selectivity allows LL-37 to disrupt bacterial membrane integrity at concentrations that spare host cells. However, LL-37's biological functions extend far beyond direct antimicrobial killing - the peptide acts as a potent immunomodulator, functioning through multiple mechanisms: it serves as a chemotactic agent for neutrophils, monocytes, and T cells through formyl peptide receptor-like 1 (FPRL1) activation; it stimulates angiogenesis and wound healing through FPRL1 and EGFR transactivation; it neutralizes lipopolysaccharide (LPS) endotoxin activity; and it disrupts bacterial biofilms at sub-inhibitory concentrations. Dysregulation of LL-37 expression is implicated in several diseases - overexpression contributes to the pathology of rosacea and psoriasis, while deficiency is associated with increased susceptibility to infections, particularly in patients with chronic wounds, burns, and immunosuppression.

Citations

Published findings on LL-37 from peer-reviewed journals.

Research Assistant
Hey, I'm the PepSpace research assistant. Ask me anything about peptides and I'll do my best to help.