Healing
LL-37
Immunity
27
Amino acids
Molecular weight
Peptide
Type
LL-37 is a 37-amino acid cationic antimicrobial peptide derived from the human cathelicidin precursor hCAP-18, naturally produced by neutrophils, macrophages, and epithelial cells. It disrupts microbial membranes through electrostatic binding and pore formation, while simultaneously modulating innate and adaptive immune responses. It is studied in research and clinical contexts for wound healing, chronic infections, and oncology.
Top researched benefits
Overview of LL-37
LL-37 binds to negatively charged bacterial membranes via its net positive charge (+6), inserts into the lipid bilayer, and forms transmembrane pores that cause cell lysis. Beyond direct microbial killing, it acts on host cells through formyl peptide receptor-like 1 (FPRL1) and P2X7 receptors to modulate cytokine production, promote angiogenesis, and recruit immune cells to sites of infection or injury.
wound healing
- 68% ulcer area reduction demonstrated with 0.5mg/mL concentration in clinical trials.
- Enhanced granulation tissue formation and wound closure.
- Accelerated healing demonstrated in animal models.
immunity
- Boosts natural immune defenses against pathogens.
- Active against MRSA and multi-drug resistant bacteria with >4 log reduction in biofilms.
- Balances immune responses without causing immunosuppression.
skin health
- Stimulates skin cell growth and regeneration.
- Promotes new blood vessel formation for tissue repair.
- Supports collagen production for wound healing.
Typical Dose
100–200 mcg per injection
Frequency
once daily, 5 days per week
Cycle Duration
2–4 weeks on, 2 weeks off
Storage
Lyophilized: stable at room temp up to 3 weeks; store desiccated below -18°C for long-term. Reconstituted: refrigerate at 2–8°C for 2–7 days or store below -18°C; avoid freeze-thaw cycles.
Chemical Makeup
Key benefits
Broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria, fungi, viruses, and biofilms through direct membrane disruption
Accelerates wound healing in venous leg ulcers and diabetic foot ulcers by stimulating keratinocyte migration, collagen synthesis, and angiogenesis
Modulates innate and adaptive immune responses by regulating cytokine production, reducing excessive inflammation without impairing pathogen clearance
Demonstrates direct antitumor activity against melanoma and other cancer cells via membrane disruption and induction of apoptosis in Phase 1 trials
Community interest
This peptide is still gaining traction in the community.
Cathelicidin Antimicrobial Peptide | Immune Defense & Wound Healing
This overview is informational and based on aggregated descriptions from studies and user reports.
Was it helpful?YesNoLL-37 Molecular Information
View the scientifc details of LL-37.
27
Amino Acids
LL-37
Ala
Ala
Position 1
Pro
Pro
Position 2
Val
Val
Position 3
Ser
Ser
Position 4
Val
Val
Position 5
Gly
Gly
Position 6
Gly
Gly
Position 7
Gly
Gly
Position 8
Thr
Thr
Position 9
Val
Val
Position 10
Leu
Leu
Position 11
Ala
Ala
Position 12
Lys
Lys
Position 13
Met
Met
Position 14
Tyr
Tyr
Position 15
Pro
Pro
Position 16
Arg
Arg
Position 17
Gly
Gly
Position 18
Asn
Asn
Position 19
His
His
Position 20
Trp
Trp
Position 21
Ala
Ala
Position 22
Val
Val
Position 23
Gly
Gly
Position 24
His
His
Position 25
Leu
Leu
Position 26
Met
Met
Position 27
Molecular Weight
4493DaChain Length
27Amino AcidsType
PeptideLL-37 Protocols
Subcutaneous injection is the primary delivery route for LL-37, offering systemic immune activation, antimicrobial defense, and wound healing support. Inject into abdominal or upper thigh fat, rotating sites frequently to minimize local irritation from this cationic peptide.
| Goal | Dosage | Frequency | Route |
|---|---|---|---|
| Immune support / antimicrobial defense | 100 | 1 day range | SubQ |
| Immune modulation (moderate) | 200 | 1 day range | SubQ |
| Advanced immune activation | 400 | 1 day range | SubQ |
| Wound healing / tissue repair | 200 | 5 week range | SubQ near wound or systemically |
| Antimicrobial / infection recovery | 300 | 1 day range | SubQ |
| Maintenance / low-dose cycle | 100 | 5 week range | SubQ |
Reconstitution Instructions
Materials needed:
Steps to reconstitute
- Allow the LL-37 vial to reach room temperature before handling (approximately 15–20 minutes)
- Draw 2 mL of bacteriostatic water into a 3 mL syringe using an 18–21 gauge drawing needle
- Insert the drawing needle through the rubber stopper of the LL-37 vial at an angle
- Inject the bacteriostatic water slowly down the inner wall of the vial — never aim the stream directly onto the lyophilized powder
- Remove the syringe and gently roll the vial between your palms for 30–60 seconds until the powder is fully dissolved — do not shake
- Allow the reconstituted solution to sit for 1–2 minutes to ensure complete dissolution before drawing a dose
- Reconstituted solution (2.5 mg/mL) should be refrigerated at 2–8°C and used within 4 weeks; for longer storage, freeze at -20°C for up to 6 months
- Draw the desired dose into a fresh insulin syringe — at 2 mL reconstitution, 1 unit on a U-100 syringe equals 25 mcg
- Pinch the skin at the injection site (abdomen or upper thigh), insert needle at 45°, inject slowly, then withdraw the needle
- Rotate injection sites with each administration to reduce local tissue reaction
LL-37 Cycle
The LL-37 Cycle section explains how long a typical cycle lasts and what to expect during each phase. Over time, your body can become less responsive with continuous use.
Taking breaks between cycles may help maintain effectiveness and support better overall results.
- Week 1-2
- Reduced bacterial load, initial wound bed preparation
- Week 2-4
- Increased granulation tissue formation, epithelial migration
- Week 4-6
- Significant wound size reduction
- Week 6-8
- Continued healing toward wound closure
Dosing tools
LL-37 Peptide Dosage Calculator
Calculate peptide doses with our visual syringe guide.
mg
Enter the total amount of peptide in the vial in milligrams (as stated on the label).
The dose you want to inject per administration, in mcg or mg.
1,000 mcg = 1 mg
1 mL
2 mL
3 mL
5 mL
Custom
Volume of bacteriostatic water you add to reconstitute the powder. Use BAC water for preservation.
Injection Results
Based on your vial and dilution inputs.
LL-37
SINGLE COMPOUNDVolume per injection
0.05
mL
Concentration
10.00
mg/mL
Doses per vial
20
doses
Total injections per vial
20 injections
How it works
Based on a 10 mg LL-37 vial diluted with 1 mL of bacteriostatic water, each 500 mcg injection equals 0.05 mL.
1mL / 100 units
5 units
0.050 mL
Reference Guide
Dosing Cycle
- Peptide
- LL-37
- Dosing
- 100–200 mcg per injection
- Dosing Frequency
- once daily, 5 days per week
- Cycle Duration
- 2–4 weeks on, 2 weeks off
- Storage
- Lyophilized: stable at room temp up to 3 weeks; store desiccated below -18°C for long-term. Reconstituted: refrigerate at 2–8°C for 2–7 days or store below -18°C; avoid freeze-thaw cycles.
Note: Triple agonist; microdose for fewer side effects
Reconstitution Tips
- Use bacteriostatic water (BAC) — contains 0.9% benzyl alcohol for preservation
- Inject water slowly — aim down the vial wall, not directly onto powder
- Never shake — gently swirl or roll the vial until dissolved
- Store properly — refrigerate at 2-8°C after reconstitution
- Use within 28 days — most reconstituted peptides remain stable for about 4 weeks
- Keep sterile — always clean vial tops with alcohol before drawing
Peptide Interactions
Research suggestions of LL-37 interactions with other common peptides and substances.
Healing
bpc
Longevity
BPC-157
SYNERGISTIC
Enhanced wound healing through complementary mechanisms.
Side effects
Contraindications
Pre-existing hypersensitivity to peptides
Compromised immune status (relative contraindication)
Non-sterile wound environments
Stop signs
Severe injection site reactions with spreading inflammation
Allergic reaction signs (rash, difficulty breathing, swelling)
Persistent flu-like symptoms
Signs of wound infection (increased redness, warmth, drainage)
Worsening wound condition or delayed healing
Unusual pain or irritation at application site
Bad signs
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Frequently asked questions
What is a peptide dosage calculator?
A peptide dosage calculator is a free tool that converts your vial size, bacteriostatic water volume, and target dose into an exact syringe draw volume. Instead of doing the reconstitution math by hand, you enter three inputs and instantly get the concentration of your solution and how many milliliters or syringeunits to draw. This calculator works for single peptide compounds and multi-peptide blends.
How do I calculate peptide dosage from a vial?
To calculate your peptide dose, divide the total peptide content of your vial in micrograms by the volume of bacteriostatic water you added in milliliters. This gives you your solution concentration in mcg/mL. Then divide your target dose by that concentration to get your draw volume. For example, a 5mg (5,000 mcg) vial reconstituted with 2mL of BAC water gives a concentration of 2,500 mcg/mL. A 250 mcg dose would require drawing 0.1mL. This calculator automates all of those steps instantly.
How much Bacteriostatic water should I add to a peptide vial?
Most people add 2mL to 3mL of bacteriostatic water per vial, but the right amount depends on the dose you want to draw and the syringe size you are using. Adding 1mL to a 5mg vial gives you a concentration of 5,000 mcg/mL, making each dose very small in volume. Adding 2mL gives you 2,500 mcg/mL, which is easier to measure on a standard insulin syringe. A general guideline is to choose a volume that puts your typical dose somewhere between 10 and 30 units on a U-100 syringe. Use the calculator above to test different water volumes and find what works for your dose.
How are peptides different from proteins?
Both are made of amino acids, but peptides are much smaller than proteins. Because of their tiny size, peptides can act like tiny messengers in the body, sending specific signals to your cells to tell them exactly what to do.
LL-37Research References
LL-37 is a phase 2 compound
LL-37
LL-37 is a phase 2 compound
Venous Leg Ulcer Trial - Grönberg et al.
68% ulcer area reduction demonstrated at optimal doses in chronic venous leg ulcers.
n.d.
Melanoma Phase I Trial
Intratumoral LL-37 in melanoma patients demonstrated safety and immune stimulation (NCT02225366).
2015
MRSA Biofilm Study - Noore et al.
>4 log reduction in MRSA biofilms compared to conventional antibiotics.
n.d.
Structural Analysis - Wang et al.
NMR spectroscopy determining 3D structure of LL-37.
n.d.
Calculate peptide dosages
Learning how to calculate a peptide dose? Use our beginner-friendly peptide dosage, blend, and accumulation calculators. Enter vial size, reconstitution volume, and target dose to get exact draw volumes instantly. No guesswork, just clear guidance that helps prevent common mistakes.
