LL-37 — The Defense Peptide
LL-37 is your body’s own front-line defender — the only human cathelicidin, a 37-amino-acid antimicrobial peptide that’s part of innate immunity’s first response. Research looks at it as a natural “broad-spectrum” peptide and a player in wound healing. Every batch is independently third-party tested for purity and ships with its own certificate of analysis.
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- ✓ Third-party COA included
- ✓ Free worldwide shipping over $99
Why source LL-37 from Aeternum Life
Every LL-37 batch is verified by an independent laboratory.
HPLC-tested identity and purity on every LL-37 lot.
Sourced and handled to strict, defined specifications.
Discreet, tracked delivery.
What is LL-37?
LL-37 (Cathelicidin) is a 37-amino-acid antimicrobial peptide — the only cathelicidin the human body produces. It’s part of the innate immune system’s first line of defense, and its name comes from its two leading leucines (LL) and 37-residue length.
Research centers on LL-37’s natural antimicrobial activity, its role in innate immunity, and its involvement in wound healing and biofilms. Aeternum Life supplies it as ultra-high-purity research material with a batch-specific Certificate of Analysis on every order.
LL-37 is the only cathelicidin humans make. It is stored as an inactive precursor, hCAP18, and released as the mature 37-residue peptide when proteases cut it free at a site of injury or infection. In solution it folds into an amphipathic α-helix — one face charged, the other hydrophobic — and that geometry is what lets it insert into and disrupt bacterial membranes. But membrane activity is only half the story: the same peptide acts as a signalling molecule, recruiting immune cells and participating in angiogenesis and wound closure, which is why it sits at the boundary between antimicrobial and repair research.
Research directions
LL-37 is a natural defense peptide, and research follows that role. Here’s the focus.
The headline: LL-37 is studied as a natural, broad-acting antimicrobial peptide.
It’s part of the body’s first-response defense, a central theme in the research.
LL-37 is also studied around wound-healing and tissue models.
A recurring focus is its interaction with microbial biofilms.
Beyond direct defense, it’s studied as a signaling molecule in innate immunity.
For research purposes only. These materials are not drugs or dietary supplements and are not intended to diagnose, treat, cure or prevent any disease.
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How LL-37 is tested
- Certificate of Analysis (COA) for every LL-37 batch
- HPLC purity & identity
- Mass-spectrometry confirmed
- Batch-tested and fully traceable
Every LL-37 lot is released only after independent verification, so what you receive matches its stated identity and purity.
Handling & Storage
Guidance for handling LL-37 as a laboratory research material.
Store lyophilized LL-37 cold and protected from light, sealed and dry until use.
Handle LL-37 according to standard laboratory practice for research materials.
Each LL-37 batch ships with a batch-specific COA for identity and purity.
LL-37 is supplied strictly for laboratory and research use. Not for human or veterinary consumption; no administration or dosing guidance is provided.
Specifications
- Name
- LL-37 (Cathelicidin)
- CAS
- 154947-66-7
- Appearance
- White lyophilized powder
- Size
- 5 mg / 10 mg per vial
- Purity
- ≥ 99% (HPLC, see COA)
- Storage
- Store at 2–8°C, protect from light
For research use. Not intended to diagnose, treat, cure or prevent any disease.
Frequently asked questions
Why is LL-37 described as both antimicrobial and immunomodulatory?
Because it does two structurally distinct jobs. Its amphipathic helix physically disrupts microbial membranes, while the same molecule also acts as a host-defence signal — attracting immune cells and taking part in wound-closure and blood-vessel formation. Research treats these as separate functions of one peptide rather than two versions of the same effect.
What is LL-37 studied for?
It’s studied around antimicrobial activity, innate immunity, wound healing and biofilms. We share these as research directions, not medical claims.
How is it handled?
LL-37 ships as a freeze-dried powder with a batch-specific COA. Reconstitution and handling guides are shared in our Telegram community.
Is LL-37 for human use?
No. Aeternum Life supplies LL-37 strictly as a research-grade material for laboratory research. It is not sold for human or veterinary consumption.
Is a COA available for LL-37?
Yes — every LL-37 batch ships with a batch-specific Certificate of Analysis covering identity and purity.
About Aeternum Life
Aeternum Life is a Japan-inspired peptide brand built on purity, transparency and rigorous testing — the same standard behind the LL-37 on this page. Every product is presented by its composition and backed by batch-specific documentation.
Explore the full Aeternum Life range
LL-37 is one of more than thirty research-grade materials we supply — each one backed by a batch-specific COA and independent testing.
- ✓ Credit card / Apple Pay accepted
- ✓ Third-party COA included
- ✓ Free worldwide shipping over $99