LL-37 on Juno

What it does

LL-37 is the active 37-amino-acid C-terminal fragment of hCAP-18, the only cathelicidin antimicrobial peptide expressed in humans. It is endogenously produced by neutrophils and epithelial cells and is a central effector of innate immunity. Beyond direct membrane-disrupting antimicrobial activity (against gram-positive and gram-negative bacteria, fungi, mycobacteria, and some enveloped viruses), LL-37 chemoattracts immune cells, neutralizes endotoxin, induces angiogenesis, and accelerates re-epithelialization. Therapeutic, exogenously-administered LL-37 has substantial preclinical and mechanistic backing, but published controlled human trials for any indication are sparse and small.

Used for

Dose

Starting: 250 mcg · 1–2× daily
Common: 375 mcg · 1–2× daily
Upper: 500 mcg · 1–2× daily
When: FlexibleNo clear circadian dependence per the guide. For active infection, twice-daily AM/PM split maintains higher plasma trough; once-daily is acceptable for maintenance or risk-reduction use.
Site: subcutaneous
Food: any

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⚠ Caution

Active autoimmune flare — LL-37 has been implicated as an autoantigen in psoriasis and lupus
Pregnancy and breastfeeding (no human safety data)
Very high doses shift toward pro-inflammatory effects — stay within standard protocols
Known hypersensitivity to peptide formulations or excipients

Medications & conditions

LL-37 with active autoimmune flare — implicated as autoantigenUser reports an active autoimmune flare. LL-37 has been implicated as an autoantigen in psoriasis and SLE per the guide; avoid during active flares until stable.

Will it work for me?

Establish a baseline (2–3 readings over 1–2 weeks before starting), then track at consistent intervals.

Blood markers

Tier 2 — Human observationalhs-CRP↓· 4–8 weeksGeneral inflammation overlay during infection resolution; not LL-37-specific.
Tier 3 — Animal / in vitroWBC differential→ normal· 4–6 weeksNormalization of WBC differential during active infection — a proxy, not a direct action marker. No LL-37-specific assay is routinely available.

Functional & psychometric

Tier 3 — Animal / in vitroInfection-resolution markers (pathogen-specific cultures, PCR)→ normal· 2–6 weeksMost directly meaningful endpoint where a known pathogen is being targeted.

Often stacked with

Thymosin Alpha-1 — Immune modulation + direct antimicrobial; useful in chronic infection or immune-suppression contexts. Inject separately — LL-37 is sensitive to handling.

Your stack

Track this peptide in your protocol — dose, schedule, vials on hand, refill projection. Stays in your browser; no account needed.

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Use this peptide

Featured in protocols

Immune Resilience — Phase 2 — Antimicrobial + anti-inflammatory layer (optional)

Co-injection & overlap

Inject separately (do not co-mix): Thymosin Alpha-1

Reconstitution & storage

Vial	BAC water	Concentration	Shelf life
5 mg	2 mL	250 mcg per 10 units	2–4 weeks

Standard 5 mg vial reconstituted with 2 mL bacteriostatic water = 2.5 mg/mL, giving 250 mcg per 10 units on a U-100 syringe. Sensitive to handling — do not shake vigorously. Use within the in-solution window noted below.

Storage. Lyophilized: refrigerate. Reconstituted: refrigerate 2–8 °C, protect from light, use within ~2–4 weeks.

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Nasal delivery

Not suitable for nasal delivery. LL-37 is dose-sensitive and handling-sensitive; the guide pairs it as a subcutaneous adjunct and does not list it among nasal-suitable peptides. Inject SQ, alone, per the compatibility section.

Reference

How it works

Cationic amphipathic α-helix that disrupts microbial membranes through electrostatic attraction to negatively charged bacterial lipid bilayers and subsequent permeabilization. Beyond direct antimicrobial action, LL-37 binds and neutralizes LPS, chemoattracts neutrophils, monocytes, and T cells via formyl peptide receptor-like 1 (FPRL1), upregulates VEGF and IL-8, and promotes keratinocyte migration. The peptide is dose-sensitive in its immune phenotype — moderate concentrations are immunosupportive and resolution-oriented, while very high concentrations shift toward pro-inflammatory cytokine release and have been implicated as autoantigen targets in psoriasis and lupus.

EvidenceTier 3 — Animal / in vitro

Tiers are per indication. The same molecule can be Tier 1 for one use and Tier 4 for another — the tier reflects published literature, not community framing.

Adjunct for chronic or biofilm-associated infections

Tier 3high confidence

Mechanistic and in-vitro work consistently shows broad-spectrum antimicrobial activity against gram-positive, gram-negative, mycobacterial, fungal, and biofilm-embedded organisms. Animal infection models support efficacy. Published human controlled trials for exogenous LL-37 in chronic-infection indications are essentially absent — use here is mechanistically rational but not RCT-supported.

Vandamme D et al. 2012 Dürr UH et al. 2006

Post-surgical infection-risk reduction

Tier 3medium confidence

Used in community post-surgical stacks (e.g., as an adjunct to Klow) for short-course infection-risk coverage in the first 7 days post-op. Rationale is mechanistic; no published surgical RCT data for exogenous LL-37 prophylaxis exists.

Vandamme D et al. 2012

Wound healing — diabetic or chronic ulcers

Tier 3high confidence

Carretero et al. (2008) demonstrated in vitro keratinocyte migration and in vivo wound-healing acceleration in a murine model. Mechanistic anchor for the chronic-wound use case; controlled human trial data is not established.

Carretero M et al. 2008

Investigational use in conditions of low endogenous cathelicidin (chronic sinusitis, atopic dermatitis)