How much water do I add to LL-37?

You can reconstitute LL-37 with 0.5, 1, or 2 mL of bacteriostatic water. Each option produces a different concentration and syringe draw for the same dose. Use the calculator to see which is easiest to measure.

What does LL-37 cost per dose?

Cost per dose depends on vial size, price paid, and your dose. Enter your vendor's price in the LL-37 calculator to see cost per dose and monthly cost.

What is the reference dose for LL-37?

The commonly referenced range is 0.1 up to 0.5 mg per dose (start low, increase slowly), taken daily, short courses. This is reference information, not a recommendation. Talk to a licensed clinician.

What are the side effects of LL-37?

Reported side effects of LL-37 include: It can irritate the injection site, with a theoretical autoimmune concern, and there is little human data.. Severity and frequency vary by person and dose.

Who should not take LL-37?

LL-37 is generally not appropriate for: No established systemic safety profile; Pregnancy; Autoimmune conditions, as a theoretical precaution. Talk to a licensed clinician before starting.

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Decoding

LL-37_

Q: What is LL-37?

LL-37 is a cathelicidin peptide used for antimicrobial & healing. LL-37 is a natural 37-amino-acid antimicrobial peptide, part of your innate immune system's first line of defense. In plain terms: it punches holes in bacteria and helps wounds heal, which is why it is explored for stubborn infections, though human data is limited.

Q: Do you cycle LL-37?

Taken in daily, short courses Course dosing is how this one is normally used. Where the course length comes from is the thing to check: for most compounds in this pattern it is convention rather than a tested schedule.

Also known as cathelicidin, hCAP-18

A natural germ-fighting peptide for stubborn infections and wound healing.

Antimicrobial & healingCathelicidin peptideResearch only

Common vial size5 mg

Dose0.1 up to 0.5 mg per dose (start low, increase slowly)

FrequencyDaily, short courses

RouteUnder the skin (subcutaneous)

StatusResearch only

MixYour choice, calculate it

CycledTaken in daily, short courses

Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.

What is LL-37?

Plain language first. The technical label stays, but it never stands alone.

Overview

LL-37 is a natural 37-amino-acid antimicrobial peptide, part of your innate immune system's first line of defense. In plain terms: it punches holes in bacteria and helps wounds heal, which is why it is explored for stubborn infections, though human data is limited.

What it's used for

A natural germ-fighting peptide used against stubborn infections, biofilms, and gut bugs, and to support wound healing.

How does LL-37 work?

What it does in the body, and where.

LL-37 is part of your innate immune system, the fast general-purpose defence that acts before your body has identified what it is fighting.

01
It physically disrupts bacterial membranes
Rather than interfering with bacterial chemistry, it punches holes in the cell wall, which is why resistance to it develops slowly.
02
It also signals wound repair
Recruiting immune cells and promoting new blood vessel growth at the site.
03
It is not selective about which membranes
At higher concentrations it damages human cells too, which is the central difficulty in developing it as a drug.
04
Human evidence is minimal
Small studies in wound healing. Nothing establishing systemic use.

Where it acts

Skin

Where this compound is thought to act.

What else is it used for?

Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.

Stubborn bacterial infections and biofilmsEarly research
Wound healingEarly research
Gut infections, which is a common reason people seek it outResearch only

How much, and do you cycle it?

The range, and whether you take breaks.

0.1 up to 0.5 mg per dose (start low, increase slowly), daily, short courses. Taken in daily, short coursesCommunity practice

Course dosing is how this one is normally used. Where the course length comes from is the thing to check: for most compounds in this pattern it is convention rather than a tested schedule.

Compare cycling across compounds →

How do I dose and price it?

Enter your vial and your dose. Pick a mix. We show the draw and the cost.

The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.

Your vial size (mg)

Printed on the vial.

What you paid per vial

Used for cost per dose only.

Your dose (mcg)

Commonly referenced range: 0.1 up to 0.5 mg per dose (start low, increase slowly)Community practice

Choose your mix

0.5 mL water1units · 10 mg/mL

Half a 100-unit syringe

1 mL water2units · 5 mg/mL

One full 100-unit syringe

Easiest

2 mL water4units · 2.5 mg/mL

Two full 100-unit syringes

your own mL

units · —

Enter your own volume

Measuring the water1 mL = one full 100-unit syringe.

Your draw

4 / 100 units

4 units is a very small line to read, so a small slip is a large error. A larger water volume above spreads the same dose across more units.

Full calculator with reorder date →Read a syringe →

How do you store it?

Before mixing, and after.

Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.

Unmixed lyophilized LL-37 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.

What are the side effects and cautions?

Known cautions and warnings for this compound.

Who should avoid it

Check these before anything else.

No established systemic safety profile
Pregnancy
Autoimmune conditions, as a theoretical precaution

Stop and get help

These are emergencies. Seek care.

Signs of an allergic reaction
A spreading rash or worsening inflammation

Common effects

Expected, and usually mild.

Injection-site irritation
Only small local experimental human studies exist
Research also notes it can be pro-inflammatory and may have pro-tumour effects in some settings

Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.

Is LL-37 approved?

And where the numbers on this page come from.

Research only

No. Not FDA-approved.

Sold for research use only. Not cleared for human consumption or medical use.

DoseFrom research and community reports. No regulator has reviewed this dose.
Vial sizeFrom what vendors typically list; not a recommendation.
Reviewed22 July 2026

What else is like LL-37?

Others in Immune support, side by side.

If you're weighing LL-37, it's worth reading Thymalin, Vilon, and Glutathione in the same class.

YOU ARE HERE

LL-37

A natural germ-fighting peptide for stubborn infections and wound healing.

Research only

Dose: 0.1 up to 0.5 mg per dose (start low, increase slowly)
How often: Daily, short courses

THYMA

Thymalin

A thymus peptide taken in courses to refresh immune function and aging.

Research only

Dose: 5 up to 10 mg per day (start low, increase slowly)
How often: 10-day courses

Vilon

A tiny bioregulator taken in courses for immunity and aging, with thin evidence.

Research only

Dose: Varies (course-based)
How often: Courses

GSH

Glutathione

Your body's master antioxidant, taken for glowing skin and detox support.

OTC / supplement

Dose: 250 up to 1000 mg per day (start low, increase slowly)
How often: Daily (oral)

What these words mean

Show glossary +

Titrate: Starting at a low dose and increasing it slowly over time so your body adjusts and side effects stay mild.
Subcutaneous: An injection just under the skin, into the fat layer, usually with a short, thin insulin needle.
Intramuscular (IM): An injection into a muscle, using a longer needle.
Reconstitution: Mixing a powdered peptide with liquid (bacteriostatic water) so it can be drawn into a syringe.
Bacteriostatic water: Sterile water with a tiny amount of preservative, used to mix powdered peptides.
Concentration: How strong the mixed peptide is, in milligrams per milliliter (mg/mL). More water makes it weaker; less water makes it stronger.
Units (on the syringe): The marks on an insulin syringe. 100 units equals 1 mL. They measure how much liquid you draw, not the dose in milligrams.
mcg and mg: Units of dose. 1 milligram (mg) equals 1,000 micrograms (mcg).
GLP-1: A natural gut hormone that lowers appetite and blood sugar. Drugs that copy it, like semaglutide, are used for weight loss.
Growth hormone secretagogue: A compound that nudges your body to release more of its own growth hormone, rather than injecting the hormone itself.
Half-life: How long a compound stays active in your body. A longer half-life means you inject less often.
Peptide vs small molecule: A peptide is a short chain of amino acids. A few items here (like MK-677 or methylene blue) are small molecules, not true peptides, but people use them the same way.
Research only: No approved dose or use in people. Sold for research and not reviewed by the FDA for safety or quality.
Investigational: Still being tested in clinical trials and not yet approved or legally sold for general use.
Banned in drug-tested sport: Prohibited by the World Anti-Doping Agency (WADA); using it can disqualify a competing athlete.

Last reviewed 22 July 2026