Six of the ten vendors we rate list LL-37, and Peptide Plugs documents its testing best: its certificate shows a Freedom Diagnostics lot tested October 15, 2026, at 99.24% purity and 5.10 mg measured. Ascension Peptides names Kovera Labs and MZ Biolabs with batch numbers at the lowest price per mg in this group ($7.80/mg), and PSPeptides posts the widest set of reports without naming the lab in the text we read. Finnrick has no LL-37 results, and FDA advisers are due to review LL-37 before the end of February 2027.
Notice: Research peptides are sold for in-vitro laboratory research only. They are not FDA-approved, not for human or animal consumption, and this page is not medical advice.
Our criterion: an LL-37-specific COA with a named lab and lot number beats a generic "third-party tested" claim. We don't test products; we check what each vendor publishes.
Regulatory status of LL-37
- FDA: LL-37 isn't an approved drug. FDA's Category 2 compounding page (content current as of April 22, 2026) lists "Cathelicidin LL-37" in its nominated-but-withdrawn table, with FDA's noted concerns about immunogenicity and "nonclinical findings of detrimental male reproductive effects and possible protumorigenic effects." McDermott reports it was removed from Category 2 on April 15, 2026.
- Pending advisory review: LL-37 wasn't voted on at the July 2026 Pharmacy Compounding Advisory Committee meeting. It is slated, with GHK-Cu and others, for a meeting "before the end of February 2027" (DLA Piper). As of October 20, 2026, no date was confirmed, and we found no FDA warning letter naming LL-37.
- WADA: the 2026 Prohibited List doesn't name LL-37 (2026 list text). Its S0 section prohibits substances "with no current approval by any governmental regulatory health authority for human therapeutic use." WADA hasn't ruled on LL-37 specifically.
- DEA: not on DEA's controlled substances list, August 2026 edition.
More: are peptides legal? and FDA peptide regulation in 2026.
LL-37 by vendor
Single-vial prices shown on October 20, 2026, including any displayed sale price. $/mg is price divided by labeled mg. Vendors appear in our editors' order, which isn't sorted by score.
| Vendor | Stocks it | Vial size(s) | Price | $/mg | LL-37 COA / lab | Review |
|---|
| NextGenPeps | Listed, out of stock | 5 mg | $68 | $13.60 | No LL-37 report seen in its COA library | Review |
| PSPeptides | Yes | 5 mg | $79.99 | $16.00 | Batch NAD-0037957, Sep 2026; lab not shown | Review |
| Ascension Peptides | Yes | 10 mg | $78 | $7.80 | Kovera Labs, batch 21-05260628; MZ Biolabs, Sep 2025 | Review |
| Peptide Plugs | Yes | 5 mg | $60 | $12.00 | Freedom Diagnostics, lot 1012OR-DK, Oct 15, 2026, 99.24% | Review |
| Swiss Chems | Yes | 5 mg | $71.99 | $14.40 | No LL-37 report shown on the page | Review |
| Licensed Peptides | Yes | 5 mg | $99.99 | $20.00 | Report code V260902-51; lab not shown | Review |
American Peptides, Blank Peptides, Peptide Confidential and Alpha Pro Peptides didn't list LL-37 for sale on October 20, 2026.
Notes on the table:
- NextGenPeps: the product page showed the 5 mg vial out of stock. LL-37 appears in its COA library product list, but we didn't see an LL-37 certificate row or PDF in the text we captured.
- PSPeptides: the product page links a September certificate plus heavy metals, endotoxin, sterility and fentanyl reports for the same batch. The page carries a "Dosage protocol" link, which we count against it.
- Ascension Peptides: the product page lists a Kovera Labs batch (PDF) and an MZ Biolabs batch 21-03250428 tested September 14, 2025 (PDF). No purity is shown on the page. Regular price is $119.99, and it's the only 10 mg vial among the vendors we rate.
- Peptide Plugs: the product page lists "LL37 5mg." Its COA library shows lot 1012OR-DK, tested October 15, 2026 by Freedom Diagnostics (the lab its product pages name): 99.24% purity and 5.10 mg measured against a 5 mg label. An earlier July 26, 2026 lot, 175-01-DK, measured 5.57 mg (11.4% over label).
- Swiss Chems: the product page is titled "LL-37 (CAP-18)." CAP-18 (hCAP-18) is the larger precursor protein, not the same molecule. The page says a COA is available per batch, but the text we read showed no LL-37 report.
- Licensed Peptides: the product page showed $99.99, down from $111.10, and links a September report PDF coded V260902-51, with no lab named in the text we read. It's the highest $/mg in this table.
Cheapest LL-37 across all 50 vendors we track
As of October 20, 2026, 50 vendors in our LL-37 price index list it (55 listings counting multi-vial kits). Per-mg figures below use in-stock single vials only.
- Cheapest per mg overall: Bulk Peptide Supply, 5 mg for $20 ($4.00/mg), well below every other listing.
- Cheapest among vendors that pass our checks (no red flags, COAs published, lot-matched or named lab; 27 vendors): Glacier Aminos, 5 mg for $31.49 ($6.30/mg), then Oasis Labs, 10 mg for $65 ($6.50/mg), and Peptidology, 5 mg for $36 ($7.20/mg).
- Median: $13.00/mg, with a range of $4.00 to $24.00. Among the vendors we rate, Ascension ($7.80/mg) and Peptide Plugs ($12.00/mg) are below the median; NextGenPeps, Swiss Chems, PSPeptides and Licensed Peptides are above it.
- Sizes: 5 mg is the usual vial (45 listings), then 10 mg (7); 2, 4 and 5.1 mg appear once each.
- Red flags: NuScience Peptides and Royal Peptides list LL-37 and received FDA warning letters dated August 24, 2026. Umbrella Labs also sells SARMs.
Compare sizes side by side with the peptide price comparison tool.
What is LL-37?
LL-37 is a 37-residue peptide that begins with two leucines, and it's the only human cathelicidin, cleaved from the precursor hCAP-18 (review). Researchers study its membrane-disrupting antimicrobial activity and its effects on host immune cells (review), as well as its role in inflammatory skin disease such as rosacea and psoriasis (review). The evidence is mostly in vitro and in animals.
How to check an LL-37 COA
- Check identity by mass. Full-length LL-37 is about 4.5 kDa. A much lighter mass points to a fragment such as KR-20, FK-16 or KR-12, and the roughly 18 kDa hCAP-18 precursor is a different molecule. "LL-38" isn't an established natural form.
- Match the lot on the certificate to your vial label, and check that the PDF's lot matches the vendor's listing.
- Read the lab name on each PDF, then look the lab up. Several LL-37 reports above don't name the lab in the page text.
- Compare measured content to the label. At a $13.00/mg median, a short-filled 5 mg vial costs more than it looks; Peptide Plugs' two LL-37 lots measured 5.10 mg and 5.57 mg against a 5 mg label.
See how to read a peptide COA, the COA checklist and the reconstitution calculator.
Independent test data
Finnrick's LL-37 page showed no published tests on October 20, 2026 ("No published LL-37 tests yet"), with two vendors listed. Every certificate above was commissioned by the vendor, which chooses the sample it sends. More on community testing: what is Finnrick?
Vendor links
In our editors' order. Each review covers the vendor's policies, red flags and full testing record.
Bottom line
For LL-37, Peptide Plugs has the most checkable record, with a named lab, a recent lot and measured content, at $12.00/mg. Ascension Peptides is the cheapest per mg among the vendors we rate and names two labs with batch numbers, though it shows no purity on the page. PSPeptides posts the widest set of reports for its batch but doesn't name the lab in the text we read and links a dosage protocol. Swiss Chems shows no LL-37 report and puts its precursor's name in the product title, NextGenPeps was out of stock, and Licensed Peptides is the most expensive. Outside our ranking, cheaper vendors that pass our checks are listed in the price index. For the full comparison, see best peptide vendors in the USA and third-party tested peptides.
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