LL-37
Also known as: Cathelicidin
LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide (starting with two leucines) cleaved from the hCAP-18 precursor. It has broad-spectrum antimicrobial activity and immunomodulatory roles, but is also implicated in the pathogenesis of autoimmune and inflammatory skin diseases including psoriasis, rosacea, and lupus. Not FDA-approved; research-use only.
Who's worth your money for LL-37
Every current seller, ranked by independent evidence — Merit Score, latest COA purity, and live $/mg (size-normalized). Prices refresh daily. Rankings are never paid.
Top Merit pick
Highest Merit Score (96) of 20 scored sellers
$94.97 · 5mg · 99.8% purity
Best value
Lowest $/mg among scored sellers
$45.00 · 10mg · 99.9% purity
Most tested
6 independent COAs on file
$45.00 · 5mg · 99.6% purity
Average price
$11.84/mg
Sellers
46
45-day trend
+0.4%
39 of 46 sellers have a current price· 11 stale hidden· 8 unverified hidden
Top Merit pick
🇺🇸 BioLongevity Labs96✓ verified at source · just now
$18.99/mg +60.4% vs avg$94.97
5mg
- 🇺🇸 Ion Peptide95
✓ verified at source · just now
$9.00/mg -24% vs avg$45.00
5mg
- 🇺🇸 Licensed Peptides95
✓ verified at source · just now
$20.00/mg +68.9% vs avg$99.99
5mg
no purityBuy code MERIT · 5% off - 🇺🇸 Peptide Crafters94
✓ verified at source · just now
$8.50/mg -28.2% vs avg$42.50
5mg
- 🇺🇸 Polaris Peptides90
✓ verified at source · just now
$12.50/mg +5.6% vs avg$125
10mg
no purity - 🇺🇸 Peptidology89
✓ verified at source · just now
$8.10/mg -31.6% vs avg$40.50
5mg
- 🇺🇸 Peptide Plugs89
✓ verified at source · just now
$12.00/mg +1.3% vs avg$60.00
5mg
- 🇺🇸 Soma Peptides89
✓ verified at source · just now
$16.60/mg +40.2% vs avg$83.00
5mg
- 🇺🇸 Ruo Bio88
✓ verified at source · just now
$7.60/mg -35.8% vs avg$38.00
5mg
- 🇺🇸 Verified Peptides87
✓ verified at source · just now
$7.80/mg -34.1% vs avg$39.00
5mg
Prices observed from public storefronts (last 24h), normalized to $/mg. "Evidence" is Merit's 0–100 Merit Score, derived only from observable verification evidence (methodology on /about); "Purity" is the latest independent COA. Some buy links are affiliate links — Merit may earn a commission at no extra cost to you, and where a vendor offers one, the code shown gets you a discount at their checkout. Affiliate status never affects price data, ranking, or the Merit Score (full policy on /disclosure). Research use only.
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About LL-37
CAS
154947-66-7
Molecular formula
C205H340N60O53
Sequence
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
Typical dose range
100–400 mcg/day subcutaneous
Half-life
~4–6 hours (tissue-dependent; limited formal PK data for native LL-37)
COAs for LL-37
47 third-party tests across 17 vendors. Each card links to the full report.
For
LL-37
by Peptide Plugs· batch 175-01-DK
For
LL-37
by Ion Peptide· batch L375-06092026
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LL-37
by Ion Peptide· batch L375-06092026
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LL-37
by Verified Peptides· batch LL05260305C
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LL-37
by Verified Peptides
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LL-37
by Verified Peptides· batch LL025602005C
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LL-37
by Real Peptides· batch Black Cap
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LL-37
by Ion Peptide· batch LL375-03232026
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LL-37
by Ion Peptide· batch LL375-03232026
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LL-37
by Modern Research Peptides· batch GCEMHK0226
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LL-37
by EZ Peptides· batch EZP-LL371002172026-01
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LL-37
by EZ Peptides· batch EZP-LL37100217-2026-01
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LL-37
by Peptidology· batch 1669
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LL-37
by Ruo Bio
For
LL-37
by Simple Peptide· batch L1-05-01162026-J
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LL-37
by Southern Aminos· batch LL050126A
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LL-37
by Simple Peptide· batch LL10-37011220236-J
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LL-37
by MedGe Peptides· batch LL375LT12
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LL-37
by MedGe Peptides· batch LL375LT12
For
LL-37
by Simple Peptide· batch LL37L2092025-J
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LL-37
by Orbitrex Peptides· batch LL5126
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LL-37
by Orbitrex Peptides
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LL-37
by Real Peptides
For
LL-37
by Kimera Chems· batch KC-L37-BLU1
20 citations indexed for LL-37
review · 2026
LL-37: Biological Mechanisms and Emerging Therapeutic Applications in Intestinal Disease
Human cathelicidin peptide LL-37 is encoded by the CAMP gene and plays a key role in innate immunity. It maintains intestinal homeostasis through antibacterial, immunomodulation, and tissue repair functions.
Study · 2026
LL-37 and citrullinated-LL-37 enhances oxylipins: citrullination attenuates LL-37-mediated COX-2-dependent chemokine response in human bronchial epithelial cells
BACKGROUND: During airway inflammation, chemokines, oxylipins (bioactive lipids) and cationic host defence peptides (CHDP) are enhanced in the lungs. However, the interplay of these molecules in the process of airway inflammation is not fully resolved.
review · 2026
β-Amyloid (Aβ) and Human Cathelicidin LL-37: Two Sides of the Same Coin?
Study · 2026
A degradable hydrogel scaffold incorporating the LL-37 for gingival soft tissue regeneration
Gingival recession exposes the roots, leads to dentin hypersensitivity, and heightens the progression of periodontitis, and poses a threat to oral health and appearance. Conventional treatment uses autogenous palatal grafts, requiring a second surgical site and adding patient discomfort.
animal · 2026
Melanoma exosomal hsa-miR-221-5p suppresses keratinocyte LL-37 to promote tumor progression
Melanoma progression is regulated by not only tumor-intrinsic factors but also dynamic crosstalk with the surrounding epidermis. Here, we observed spatial suppression of cathelicidin LL-37 in tumor-adjacent epidermis compared with that in distal regions in clinical specimens.
review · 2026
β-Amyloid (Aβ) and Human Cathelicidin LL-37: Two Sides of the Same Coin?
Physiologically produced circulating β-amyloid (Aβ) exerts critical physiological functions. Although Aβ is a key player in Alzheimer's disease (AD), it may initially be beneficial at the onset of infection.