Peptide Guide + Calculator
LL-37 Reconstitution Calculator & Guide
Cathelicidin Antimicrobial Peptide / CAMP
LL-37 is the 37-amino-acid active human cathelicidin peptide derived from hCAP18. It participates in innate immunity, antimicrobial defense, inflammation, cell migration, and wound biology. Human topical wound studies exist, but LL-37 is not an FDA-approved drug, injectable safety is not established, and FDA has highlighted immunogenicity, impurity, reproductive, and potential tissue-specific protumorigenic concerns for compounded LL-37.
Evidence Snapshot
LL-37 research at a glance
Standardized regulatory and evidence context so research compounds, investigational drugs, and approved medications are not treated as if they have the same level of human evidence.
Regulatory status
Not FDA-approvedDevelopment / evidence stage
Exploratory / limited human evidence
Human evidence level
Very limited human evidencePrimary mechanism
Human cathelicidin antimicrobial peptide with direct host-defense activity plus immunomodulatory and wound-biology effects.
WADA context
Non-approved substance — S0 may applyHuman intervention evidence
Topical LL-37 has been evaluated in randomized wound-healing trials, including a Phase IIb venous-leg-ulcer study. These topical data do not establish injectable safety or effectiveness.
Human biology evidence
LL-37 is an endogenous human innate-immune peptide with extensive mechanistic biology and human tissue-expression research.
Key takeaway
LL-37 has more human topical research than many online recovery peptides, but that evidence is route-specific and does not justify claims about injected LL-37.
Evidence labels describe the research base and regulatory context; they are not treatment, dosing, or use recommendations. Review dates describe the last BACToBasics source check for this evidence summary. Anti-doping rules can change and should be verified with the applicable authority.
LL-37 Reconstitution Calculator
Enter the vial amount, liquid volume, and amount you want to calculate. BACToBasics will automatically calculate concentration, liquid volume, and U-100 syringe-unit equivalents.
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Calculator values are educational math inputs only. They are not recommended preparation amounts, doses, or use protocols.
LL-37 Reconstitution Math
Reconstitution math starts with the amount contained in the vial and the liquid volume used in the calculation. Dividing the vial amount by the liquid volume gives the resulting concentration.
Example vial amount
1 mg
| Liquid Volume | Calculation | Concentration |
|---|---|---|
| 1 mL | 1 mg ÷ 1 mL | 1 mg/mL |
| 2 mL | 1 mg ÷ 2 mL | 0.5 mg/mL |
| 3 mL | 1 mg ÷ 3 mL | 0.3333 mg/mL |
This table demonstrates concentration math only. The liquid volumes shown are examples for comparison and are not preparation recommendations.
More Reconstitution Tools
Need to compare different liquid volumes or convert between mg, mcg, mL, and U-100 units? Use the dedicated BACToBasics calculator tools.
What is LL-37?
LL-37 is the active 37-amino-acid peptide generated from the human cathelicidin precursor hCAP18. It is produced by several immune and epithelial cell types and is part of the innate immune system. Research has examined antimicrobial activity, immune signaling, angiogenesis, keratinocyte behavior, and wound repair.
Is LL-37 an antibiotic?
LL-37 has direct antimicrobial activity in laboratory systems, but it is not an FDA-approved antibiotic and should not be treated as a substitute for an approved antimicrobial drug. Its biology is broader than direct microbe killing because it also interacts with immune and tissue-repair pathways.
Human wound-healing research
Topical LL-37 has reached human clinical research. A randomized Phase IIb study in 148 people with hard-to-heal venous leg ulcers did not show a significant healing benefit across the full study population, although a post hoc subgroup with larger wounds showed signals that warranted further study. A separate randomized study evaluated LL-37 cream in diabetic foot ulcers.
Topical evidence is not injectable evidence
Human wound studies used topical formulations. Those data should not be generalized to subcutaneous or systemic LL-37 use. Route changes exposure, distribution, immune effects, and safety considerations, and FDA states that it lacks sufficient safety-related information to know whether compounded LL-37 would cause harm when administered to humans.
FDA compounding concerns
FDA identifies potential immunogenicity, peptide-related impurity, and active-pharmaceutical-ingredient characterization concerns for compounded cathelicidin LL-37. FDA also notes nonclinical findings suggesting detrimental effects on male reproduction and possible protumorigenic activity in some tissues.
LL-37 and cancer biology
LL-37 is not accurately described as simply pro-cancer or anti-cancer. Its effects vary by tissue and experimental context. FDA specifically highlights nonclinical evidence suggesting protumorigenic effects in some tissues, which is a reason to avoid broad safety claims based only on antimicrobial or wound-healing biology.
LL-37 vs KPV
LL-37 and KPV are both discussed in inflammation and immune-research communities but are very different molecules. LL-37 is a 37-amino-acid human cathelicidin with direct antimicrobial and immunomodulatory biology; KPV is a three-amino-acid fragment of alpha-MSH studied mainly for anti-inflammatory signaling. There is no established clinical head-to-head treatment comparison.
Is LL-37 FDA-approved?
No. There is no FDA-approved LL-37 drug for infection, wound healing, immune support, gastrointestinal disease, recovery, or general wellness. Research-market products do not have the same evidence, manufacturing controls, or regulatory review as approved medications.
LL-37 reconstitution math
The calculator on this page performs generic concentration, mL, and U-100 syringe-unit math from user-entered vial and liquid values. It does not recommend injectable LL-37 use, a wound-treatment protocol, or an antimicrobial regimen.
Explore more about LL-37
6 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Explore more about LL-37
6 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Related peptide guides
Related guides are ranked from shared comparison pages, shared blend pages, and peptide category rather than a hand-maintained link list.
Relevant glossary concepts
Definitions are matched against the guide's structured title, subtitle, description, and educational sections.
FDA-Approved
A status indicating that the FDA has approved a specific drug product for one or more labeled uses after reviewing the required evidence and manufacturing information.
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GlossaryMilliliter (mL)
A metric unit of liquid volume equal to one-thousandth of a liter.
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GlossaryConcentration
The amount of a substance contained in a given volume of liquid, such as mg/mL or mcg/mL.
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LL-37 FAQ
Tap a question to expand only the answer you want to read.
Is LL-37 naturally found in humans?
Yes. LL-37 is the active peptide derived from the human cathelicidin precursor hCAP18 and is part of innate immune defense.
Is LL-37 FDA-approved?
No. LL-37 is not an FDA-approved drug for infection, wound healing, immune support, or any other indication.
Has LL-37 been studied in humans?
Yes. Topical LL-37 has been evaluated in human wound-healing studies, including a randomized Phase IIb trial in venous leg ulcers. That does not establish injectable safety or effectiveness.
Does LL-37 kill bacteria?
LL-37 has antimicrobial activity in laboratory research, but it is not an approved antibiotic and laboratory antimicrobial activity does not prove clinical effectiveness for treating an infection.
Is injectable LL-37 well studied?
No. FDA states that it lacks sufficient safety-related information to know whether compounded LL-37 would cause harm when administered to humans, and topical human data should not be generalized to injection.
What is the difference between LL-37 and KPV?
LL-37 is a 37-amino-acid cathelicidin with antimicrobial and immune-signaling activity, while KPV is a three-amino-acid alpha-MSH fragment studied mainly for anti-inflammatory effects.
Can BACToBasics calculate LL-37 vial math?
Yes. It can perform generic labeled-vial concentration, mL, and U-100 syringe-unit math without recommending a dose, route, or treatment protocol.
Sources & References
4 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
Sources & References
4 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
FDA compounding-safety summary for cathelicidin LL-37, including immunogenicity, impurity, reproductive, and potential tissue-specific protumorigenic concerns.
Randomized placebo-controlled trial in 148 patients; no significant healing improvement across the full cohort, with a post hoc signal in patients with larger wounds. PMID: 34687253.
Human topical wound study evaluating LL-37 cream in diabetic foot ulcers. PMID: 37480520.
Human tissue study examining LL-37 expression and innate immune biology in atherosclerotic lesions. PMID: 16645154.
BACToBasics provides educational information and math tools only. This content is not medical advice, dosing advice, injection instruction, or a recommendation to use any peptide or medication.