LL-37
Cathelicidin (human)
LL-37 (Cathelicidin (human)) is a healing & recovery research compound. Innate-immune antimicrobial peptide — disrupts microbial membranes and modulates inflammation and wound healing.
LL-37 quick facts
| Reported research dose | 100mcg-500mcg |
| Route | Subq |
| Frequency | 3-5x A Week |
| Half-life | Short (minutes-hours) |
| Forms | Injectable |
| Evidence level | In-vitro + animal |
Antimicrobial/biofilm and gut interest. Powerful — can be pro-inflammatory, so it's not a 'more is better' peptide.
How LL-37 works
Innate-immune antimicrobial peptide — disrupts microbial membranes and modulates inflammation and wound healing.
Proposed benefits
Antimicrobial, biofilm and gut-immune support.
✅ Clinically validated
- Human trials exist and are small — topical LL-37 was studied in hard-to-heal venous leg ulcers in a phase 1/2 trial, which reported improved healing at lower doses and, notably, less benefit at the highest dose. A dose-response that turns over is a real finding, not noise.
📊 Correlative data
- Used in the research community for chronic infection and biofilm-associated conditions. Injection-site reactions are the most consistent report, which the mechanism predicts.
🧪 Theoretical / extrapolated
- The only human cathelicidin — an endogenous antimicrobial peptide that disrupts bacterial membranes directly and also modulates immune signalling and promotes angiogenesis. Vitamin D upregulates its expression, which is one of the better-supported links between vitamin D status and infection.
- Membrane disruption is not selective, which is why high concentrations irritate host tissue too — and the likely explanation for the inverted dose-response in the ulcer trial.
These tiers tell you how much human evidence exists — not how well something works. This is the research space, and most of what’s in here is new rather than disproven. Something sitting at “theoretical” usually means nobody has funded the trial, not that the trial was run and failed.
The trap runs the other way too: something can be clinically validated and still do very little for you specifically. A statistically significant result in a study population is not a promise about your body.
- ✅ Clinically validated — human randomised trials or meta-analyses support it. The strongest footing available.
- 📊 Correlative — observational or epidemiological data. Suggestive, and genuinely useful for direction, but it cannot establish cause.
- 🧪 Theoretical / mechanistic — the mechanism is understood and often demonstrated in cells or animals, and the human trial doesn’t exist yet. Unproven is not the same as ineffective. Plenty of what’s standard practice today sat here five years ago.
✗ is a safety flag, not a grade. Where you see it, the concern is harm — not a disappointing trial. A compound tested for one purpose and found not to help there can still be worth studying somewhere else, so a negative result never gets rendered as a cross. It sits alongside the tier, because something can be both well-studied and genuinely risky.
My job is to tell you which one you’re looking at, and let you make the call. Grading something low isn’t me dismissing it — it’s me refusing to oversell it. This is the research space, and being able to reason forward from a mechanism matters as much as waiting for the trial.
LL-37 — safety, predicted from mechanism
Much of this compound class has never been through a human safety trial. Rather than say nothing — or print a generic warning — this is what its known mechanism predicts could go wrong, and what you can do about it. Predictions are labelled as predictions.
What the mechanism predicts
Derived from what this molecule does, not from a trial.
- Repair peptides work by promoting angiogenesis — new blood vessel growth — plus fibroblast migration and growth-factor signalling. That is what makes them useful, and it is the entire basis of the one theoretical concern worth naming: angiogenesis is also what a tumour needs to grow beyond a few millimetres.
- There is no evidence these compounds cause or accelerate cancer. There is a mechanistic reason not to run a pro-angiogenic agent systemically with an active or recently treated malignancy, and that reasoning stands without a trial.
- The second predicted issue is more mundane and more likely: they can mask a signal. Something that reduces pain and inflammation around an injury lets you load a tissue that has not finished healing.
What has actually been reported
- Very well tolerated in reported use. Injection-site reactions and transient light-headedness are the common complaints.
- Human data is thin — most of the literature is rodent — so 'well tolerated' here means 'no signal has emerged from a lot of informal use', which is weaker than a clean trial and stronger than nothing.
How to reduce the risk
Each of these follows from the same mechanism as the prediction.
- Stop when the thing you were treating has resolved. There is no mechanism here that demands a clock, and equally no reason to keep running a pro-angiogenic signal once the job is done.
- Do not let reduced pain set your training load. The tissue heals on its own timeline whether or not you can feel it. Reloading early on the strength of feeling better is the most common way people turn a good result into a re-injury.
- Get the diagnosis before the peptide. These accelerate healing of things that heal. A tear that needs surgical repair does not become a tear that does not, and the delay costs you.
- One injury, one compound, long enough to judge it. Otherwise you learn nothing transferable for next time.
What it does to your bloodwork
A fact about the assay, not a guess about the drug.
- Nothing routine tracks these directly. The endpoint is the injury, which means your own honest assessment of function is the measurement.
Don't run this if
- Active or recently treated malignancy — the angiogenesis reasoning.
- Any undiagnosed lump or lesion. Find out what it is first.
The honest unknown
- Long-term systemic exposure in humans has never been characterised. The use case is naturally self-limiting — you stop when the injury resolves — which is why this matters less here than it would elsewhere.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this with a pharmacist or doctor.
Where to get LL-37
Buy LL-37 at Flawless Compounds →LL-37 — interference & stacking
Predicted from mechanism, not from an interaction study. There are no trials of these combinations — what follows is what the biology implies, so treat it as a reason to watch something, not as a finding.
What LL-37 moves on your bloodwork
These are the markers this compound is expected to move, and which direction. Knowing that in advance is mostly about NOT panicking: some of these moving is the compound working.
- hs-CRP (High-Sensitivity C-Reactive Protein) — ↓ expected to fall
If a repair peptide is doing anything systemic, inflammation is where it would plausibly show.
What to do: Worth a baseline if you are running one for a chronic issue rather than an acute injury. - Comprehensive Metabolic Panel (CMP) — ◆ worth watching
Standard baseline. Nothing in this class predicts a specific abnormality — which is itself worth saying rather than inventing one.
What to do: Annual is fine unless something changes.
- Which compounds push the same lever, and why the dose adds up faster than people count
- What blunts it — the stacks that waste your money
- What compounds the risk, so a side effect arrives sooner than any one of them suggests
- Coach Cam's read on running it alongside the rest of your protocol
Get the complete breakdown for LL-37 — inside the Academy alongside the full interactive Vault.
Unlock in the Academy — $10/mo →The honest position on this class is that the proliferation question is unresolved — anything that accelerates tissue repair is acting on pathways cancer also uses. Nobody has studied it properly either way.
- How to work up to it, and when not to
- When to take it, and why that window
- Cycle length
- Time off between cycles
- Fasted or fed, and when in the day
- Needle gauge and injection site
- Coach Cam's personal notes
Get the complete breakdown for LL-37 — inside the Academy alongside the full interactive Vault.
Unlock in the Academy — $10/mo →Bloodwork to run alongside LL-37
Run these before you start, and again after 8–12 weeks. A baseline you didn’t take is one you can never go back for.
| Marker | What it’s watching for |
|---|---|
| hs-CRP (High-Sensitivity C-Reactive Protein) | Baseline inflammation — the thing you're claiming to reduce |
| Complete Blood Count (CBC) with Differential | Infection, anaemia and platelet count before anything injectable |
| Comprehensive Metabolic Panel (CMP) | Liver and kidney baseline |
| Vitamin D (25-Hydroxy) | Low D slows soft-tissue and bone healing measurably |
The Inflammation Deep Dive panel covers these in one order — 10 markers, $248.35 with the discount applied.
Check results you already have → · All 102 markers A–Z
LL-37 — frequently asked questions
What is LL-37?
LL-37 (Cathelicidin (human)) is a healing & recovery research compound. Innate-immune antimicrobial peptide — disrupts microbial membranes and modulates inflammation and wound healing.
Is the full LL-37 protocol on this page?
The reported research dose is on this page, along with how LL-37 works and the evidence behind it. The protocol — how to work up to it, frequency, cycle length, time off, what not to stack it with and Coach Cam's notes — is inside the Academy.
What is the half-life of LL-37?
LL-37 has an approximate half-life of Short (minutes-hours), which is part of what determines how often it's dosed.
What's the evidence behind LL-37?
Current evidence level: In-vitro + animal. LL-37 is offered for research purposes only and is not an approved medicine.
Want Coach Cam's exact LL-37 protocol?
Dosing schedules, stacking, cycle timing and my personal notes live inside the Academy — plus the full interactive Vault of 237 compounds & 350 supplements.
Join the Academy — $10/mo →What LL-37 is used for
LL-37 appears under 3 goals in the Vault’s goal router, grouped by the mechanism it works through rather than by how much trial evidence exists. Each link opens that pathway in full, with the alternatives beside it and the bloodwork that tests it.