LL-37 (Human Cathelicidin Antimicrobial Peptide)
Published · Researched 2026-09-21
Overview
LL-37 is a 37-amino-acid, amphipathic alpha-helical peptide (MW ~4,493.3 Da, CAS 154947-66-7, formula C205H340N60O53, sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) — the only human member of the cathelicidin antimicrobial peptide family, released by neutrophils as part of innate immunity. It kills bacteria (including multidrug-resistant strains and biofilms) by toroidal pore formation in microbial membranes, modulates inflammation (FPR2, TLR signaling), promotes angiogenesis and keratinocyte migration, and participates in wound-healing and tissue-repair pathways. In the biohacker community it sits at the intersection of immune and healing: used/discussed for chronic wound healing, biofilm-associated infections, gut health, and autoimmune-adjacent inflammation — a different lane from the BPC/TB-500 tissue-repair pair. Research chemical, not for human use; no FDA/EMA approval for any indication. Human clinical work is early (diabetic-foot-ulcer and wound-fluid studies show signal, mostly topical/experimental). Worth noting: LL-37 is cytotoxic to normal eukaryotic cells at higher concentrations and can be pro-inflammatory in some contexts — the community treats it as infection-specific, not a general recovery peptide.
Social standing
- Platform pulse: LL-37 is one of the "hot" peptides in biohacker/influencer circles rather than the peptide-forum mainstream. Key nodes: Jay Campbell's long-form LL-37 write-up (jaycampbell.com) summarizing wound-healing and gut-health use, citing SuperHuman Radio's Carl Lanore discussing his own gut-health use in detail on YouTube; Dr. Joy Kong's podcast clip "Immune Peptides (Thymosin Alpha-1, LL-37)" (DrJoyClips YouTube) covering its antimicrobial, wound-healing, and anti-inflammatory profile; vendor-community content (Core Peptides, Biolongevity Labs, SWolverine) detailing mechanisms for their audiences; an MDPI review noting rising publication counts. Direct Threads/FB-Group discussion was not observable this session (social.search infrastructure timed out; central sweep's "pentosan/ARA-290/KPV" Threads query surfaced only KPV-adjacent content).
- Group consensus: LL-37 is treated as the biofilm/chronic-infection specialist of the healing-adjacent peptides — the thing you look at when standard recovery peptides and antibiotics haven't resolved a stubborn wound or gut issue. Community framing: antimicrobial first, wound-healing second; not interchangeable with BPC-157/TB-500.
- Viral/educational moments: harm-reduction explainer content performs well in this space (the central sweep noted a clinical-scientist-style peptide explainer going viral at 95 likes); LL-37 rides that same educational-content wave via practitioner/influencer explainers rather than single viral posts.
- Main praise: broad-spectrum antimicrobial action without the resistance dynamics of antibiotics; wound-healing support (pressure-ulcer and venous-leg-ulcer research summarized by Campbell/Core Peptides showing improved epithelialization and angiogenesis markers); gut-health anecdotes in biohacker media.
- Main complaints: (1) pro-inflammatory potential — it can drive inflammation depending on context, so it's not a casual "feel-better" peptide; (2) limited human data — most evidence is in-vitro, animal, or ex-vivo wound-fluid work; (3) relatively expensive per mg and less widely stocked than BPC/TB-500; (4) no standardized community protocols — discussion stays qualitative and cautious.
- Brief attributed quotes (paraphrased): "LL-37 was degraded by trypsin but not by matrix metalloproteinase-9, and was fairly resistant to proteolytic cleavage by wound fluid" — wound-fluid study summarized by Jay Campbell, supporting the case for topical/chronic-wound use; "LL37 may have a key role in wound regeneration through vascularization" (Ramos et al., via Core Peptides); from a peptide-catalog note in the biohacker community: "Antimicrobial/immune peptide; can be pro-inflammatory; infection-specific, research-stage" (joecooksey/obsidianvault peptide catalog).
Social validation
Tier 2, flagged: no direct Threads/FB-Group posts observed this session. Named sources and what each proves:
- Biohacker influencer/media: Jay Campbell (jaycampbell.com — wound-healing research summary + community-use framing), Dr. Joy Kong podcast clip (YouTube — practitioner explainer pairing LL-37 with Thymosin Alpha-1), Carl Lanore/SuperHuman Radio (self-reported gut-health use) — prove sustained influencer-layer discussion in healing/immune context.
- Vendor-community content: Core Peptides (corepeptides.com — immune-cell modulation and wound-tissue-repair write-up), Biolongevity Labs (biolongevitylabs.com — diabetic-foot-ulcer clinical signals), SWolverine (AMP overview positioning LL-37 as the human cathelicidin) — prove the peptide-commerce community treats LL-37 as a stocked, discussed product.
- Scientific literature signal: MDPI reviews (rising publication counts; LL-37's wound-healing, angiogenic, biofilm-suppression roles) — prove the mechanism story the community repeats is grounded in real (preclinical) literature.
Missing for Tier 1: first-hand FB-Group threads or Threads discussion posts observed in this track's sweep. FB Marketplace used range = N/A.
Key specs table
| Property | Detail |
|---|---|
| Sequence | LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES (37 AA, amphipathic alpha-helix) |
| Molecular weight | ~4,493.3 Da; formula C205H340N60O53 |
| CAS | 154947-66-7 (PubChem CID 16198951) |
| Typical vial size sold | 5 mg lyophilized vials (RUO vendors); lab-reagent sizes 1–10 mg at much higher prices |
| Half-life | UNVERIFIED for community use; research notes LL-37 is susceptible to trypsin-like proteases but relatively resistant to wound-fluid proteolysis (ex-vivo data) — no reliable systemic half-life figure in community use |
| Solubility | Soluble in water (vendor spec); lab guidance also notes DMSO for some applications |
| Storage | Lyophilized: ≤6 °C sealed, away from heat/light/moisture (Protide Health); general peptide guidance: fridge 2–8 °C up to ~6 months, freezer −20 °C for years; reconstituted: refrigerate, avoid freeze-thaw (Particle Peptides) |
Pricing
Observed 2026-09-20. Gray-market RUO vendors only; FB Marketplace used range = N/A.
- Protide Health — LL-37 5 mg, $75.00 (protidehealth.com/product/ll-37-5mg/, observed 2026-09-20). Third-party HPLC-MS claimed, 99.76% purity stated. → $15.00/mg.
- Particle Peptides (EU) — LL-37 5 mg, €65.03 (particlepeptides.com, observed 2026-09-20). Acetate salt, ≥99%.
- ERP/peer-catalog community price point — LL-37 5 mg listed at $99 (joecooksey/obsidianvault peptide catalog, community-curated, 2026).
- Lab-reagent tier (not community product): GLPBio 5 mg $234 / 10 mg $363; AnaSpec/Fisher 1 mg $302.58; MyBioSource 0.1 mg $695 — illustrating the gap between research-chemical gray-market and catalog-reagent pricing.
What's included / what's needed
Included: lyophilized powder in a sealed vial (typically 5 mg). Needed: bacteriostatic water or sterile water for reconstitution (per vendor), syringes, alcohol swabs, refrigeration (2–8 °C) for the reconstituted vial. Sold for laboratory research use only — not human consumption, per vendor labeling.
Support reality
- Warranty/returns: standard RUO terms — limited defect replacement; opened research vials generally non-returnable (terms vary by vendor — UNVERIFIED per-vendor detail).
- Third-party testing culture: Janoshik COAs are the community reference; Protide Health publishes claimed third-party HPLC-MS results (99.76%). LL-37 is stocked by fewer vendors than BPC/TB-500, so vendor reputation discourse is thinner — buyers lean on the same general peptide-vendor quality discussions.
- Community reports on vendor quality: no LL-37-specific QC scandals surfaced in this session's research; the general caveat applies — identity/purity is only as good as the COA, and LL-37's higher price per mg makes it a plausible counterfeit target (UNVERIFIED as a documented occurrence).
Community verdict
LL-37 is the healing track's infection-and-wound specialist: genuine biohacker enthusiasm grounded in real antimicrobial and wound-healing literature, but the community conversation stays appropriately cautious — it's discussed as an infection-specific tool with pro-inflammatory edge cases, not a general recovery peptide, and the human evidence remains early. Of the candidates for the fourth slot, it has the strongest real signal in a healing context, well ahead of the immune-only Thymosin Alpha-1 and the longevity-framed Epithalon.
Regulatory & safety status
RESEARCH CHEMICAL NOT FOR HUMAN USE. LL-37 has no FDA/EMA approval for any indication; human data is limited to early wound-healing and antimicrobial studies (mostly topical/experimental). It is sold strictly as a research chemical. Safety notes from the literature the community cites: cytotoxic to normal eukaryotic cells at higher concentrations; can be pro-inflammatory depending on cellular context; implicated in some autoimmune/inflammatory pathways. None of this is a human-use safety profile — it is the reason community discussion treats LL-37 as infection-specific and research-stage.
Photos
6 distinct real photographs, verified and converted to JPEG. No photo is reused across views or items.
- Views present: hero, side, top, detail, scale, box (ll-37-hero.jpg, ll-37-side.jpg, ll-37-top.jpg, ll-37-detail.jpg, ll-37-scale.jpg, ll-37-box.jpg).
- Missing views: rear, in-use — no real photos of these views found; named honestly rather than substituted.
- Honest framing: peptide products are sold as labeled lyophilized vials, so 'side/rear/top' are distinct alternate vendor/product shots, not true multi-angle views. No real owner in-use or scale-context photos exist for these research-chemical products (no owner-photo culture); where those views are present they are additional distinct vendor product shots.
Not medical advice. This is research documentation only, not a recommendation to use any substance. The peptide products are sold as research chemicals not intended for human use.
Named sources
- Biohacker influencer/media — Jay Campbell (jaycampbell.com — wound-healing research summary + community-use framing), Dr. Joy Kong podcast clip (YouTube — practitioner explainer pairing LL-37 with Thymosin Alpha-1), Carl Lanore/SuperHuman Radio (self-reported gut-health use) — prove sustained influencer-layer discussion in healing/immune context.
- Vendor-community content — Core Peptides (corepeptides.com — immune-cell modulation and wound-tissue-repair write-up), Biolongevity Labs (biolongevitylabs.com — diabetic-foot-ulcer clinical signals), SWolverine (AMP overview positioning LL-37 as the human cathelicidin) — prove the peptide-commerce community treats LL-37 as a stocked, discussed product.
- Scientific literature signal — MDPI reviews (rising publication counts
- MDPI review — Joy Kong's** podcast clip "Immune Peptides (Thymosin Alpha-1, LL-37)" (DrJoyClips YouTube) covering its antimicrobial, wound-healing, and anti-inflammatory profile; vendor-community content (Core Peptides, Biolongevity Labs, SWolverine) detailing mechanisms…
- Core — - **Brief attributed quotes (paraphrased):** "LL-37 was degraded by trypsin but not by matrix metalloproteinase-9, and was fairly resistant to proteolytic cleavage by wound fluid"…
Source URLs were not recorded for these references.