Vendor comparison · 2026
LL-37 vendors: 14 compared on COAs and price
Tissue & recoveryAlso known as Cathelicidin, CAP-18
Evidence tier
Substantial published literature
3,144 publications over 35 years · trials not yet curated
- Vendors carrying it
- 14
- 13 with a listed price
- Vendors with checkable COAs
- 4
- 4 publish any certificate
- Lots tested
- 4
- 4 naming a checkable lab
- Independent assays
- 0
- none on file yet
- Newest assay
- 17 Sept 2026
- oldest 21 Jan 2026
- Laboratories named
- 2
- most often Freedom Diagnostics Testing
- Median label gap
- 17.7%
- 25% of lots within 5% of label
- Median purity
- 99.77%
- 3 of 4 lots at 99% or above
- Lowest price per mg
- $5.25
- peer median $12.00
- Publications located
- 3.1k
- researched since 1991
Source: PepIndex, an independent index of research-peptide vendors. No vendor can pay for a rank, every score is computed by a published formula, and every figure links to the document it was read from.
Modern Aminos has the most checkable LL-37 testing in this index: 1 lot assayed by Freedom Diagnostics Testing, the newest on 24 Jun 2026. The lowest listed price is $5.25 per mg at Ascend Science, against a peer median of $12.00. 14 vendors carrying LL-37 are compared below. 4 publish at least one certificate naming a checkable laboratory, 4 lot records are on file, and none is an independently commissioned assay. Figures are PepIndex's own: it is an independent index of research-peptide vendors, no vendor can pay for a rank, and each figure links to the certificate it was read from.
Every vendor carrying LL-37
| # | Vendor | Score here | Price / mg | Lots | Newest test | Laboratory | Mean purity | Label gap | Reports |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ascend ScienceISO/IEC 17025 | 93.494% | $5.25 (44%) | 0 | — | — | — | — | |
| 2 | Amino ClubISO/IEC 17025Age-gated COAs | 92.598% | $7.00 (58%) | 0 | — | — | — | — | |
| 3 | Ascension Peptides | 86.689% | $8.90 (74%) | 0 | — | — | — | — | no reportVisit site |
| 4 | Modern AminosISO/IEC 17025COAs need an account | 85.297% | $9.40 (78%) | 1 / 1 | Freedom Diagnostics Testing | 99.9% | 26.4% | ||
| 5 | PeptidePlugs | 84.394% | $12.00 (100%) | 1 / 1 | Freedom Diagnostics Testing | 99.7% | 11.4% | ||
| 6 | Simple Peptide | 84.192% | $9.00 (75%) | 0 | — | — | — | — | no reportVisit site |
| 7 | Protide HealthAge-gated COAs | 73.192% | $15.00 (125%) | 0 | — | — | — | — | no reportVisit site |
| 8 | Bench Grade Peptides | 7089% | $18.40 (153%) | 1 / 1 | Freedom Diagnostics Testing | 99.9% | 24.0% | ||
| 9 | Good Science Bio | 69.271% | $11.00 (92%) | 0 | — | — | — | — | no reportVisit site |
| 10 | Paramount Peptides | 61.971% | $15.00 (125%) | 0 | — | — | — | — | no reportVisit site |
| 11 | GenX Peptides | 60.869% | $15.00 (125%) | 0 | — | — | — | — | no reportVisit site |
| 12 | Vial Drop Labs | 59.474% | — | 1 / 1 | KMD Analytical (KMD Group LLC) | 97.3% | 4.4% | ||
| 13 | BioLongevity Labs | 55.972% | $18.99 (158%) | 0 | — | — | — | — | no reportVisit site |
| 14 | Biotech Peptides | 53.460% | $17.20 (143%) | 0 | — | — | — | — | no reportVisit site |
Independent assays
No independently commissioned assay of LL-37 is on file. All 4 records below were published by the vendor that sells the product, naming the laboratory shown. PepIndex does not yet commission its own assays, so nothing on this page establishes what is in a vial beyond the vendor’s own certificate. A record moves into this section the moment an assay commissioned by anyone other than the seller is indexed.
What the certificates show
3 of 4 lots at 99% or above; median 99.77%.
| Range | lots |
|---|---|
| <95% | 0 |
| 95–97% | 0 |
| 97–98% | 1 |
| 98–99% | 0 |
| 99–99.5% | 0 |
| ≥99.5% | 3 |
25% of lots within 5% of the labelled mass; median gap 17.7%.
| Range | lots |
|---|---|
| ≤2% | 0 |
| 2–5% | 1 |
| 5–10% | 0 |
| 10–20% | 1 |
| >20% | 2 |
13 vendors, $5.25 to $18.99; median $12.00.
| Range | vendors |
|---|---|
| $5.00–$10.00 | 5 |
| $10.00–$15.00 | 2 |
| $15.00–$20.00 | 6 |
Purity and mass are read from each certificate as published; the label gap is |labeled − assayed| ÷ labeled. Every value behind these bars is in the certificate table below.
Laboratories used
| Laboratory | Lots | Vendors | Share | Verify |
|---|---|---|---|---|
| Freedom Diagnostics TestingUS | 3 | 3 | 75% | Public lookup |
| KMD Analytical (KMD Group LLC)US | 1 | 1 | 25% | Public lookup |
Every certificate record
| Vendor | Lot | Tested | Lab | Labeled | Assayed | Discrepancy | Purity | Report |
|---|---|---|---|---|---|---|---|---|
| VDVial Drop Labs | VDL-20260901-QFT7 | KMD Analytical (KMD Group LLC) | 5 mg | 5.22 mg | 4.4% | 97.3% | Vendor-published | |
 PeptidePlugs | 175-01-DK | Freedom Diagnostics Testing | 5 mg | 5.57 mg | 11.4% | 99.7% | Vendor-published | |
 Modern Aminos | BX-P-S9G5 | Freedom Diagnostics Testing | 5 mg | 6.32 mg | 26.4% | 99.9% | Vendor-published | |
 Bench Grade Peptides | LL05-01162026-J | Freedom Diagnostics Testing | 5 mg | 6.2 mg | 24.0% | 99.9% | Vendor-published |
Score breakdown
The score has two halves: the research base — how long the compound has been studied and how much has been published — and the quality of the evidence the market produces for it, aggregated across every vendor that carries it: assayed purity, lot-to-lot consistency, readable third-party certificates and those vendors’ review record. It measures the evidence base, not the merits or safety of the substance.
Studied since 1991 — 35 years of published research
How long the compound has been studied. Fifteen years or more of published literature earns full marks; a newer compound earns less.
3,144 publications indexed in PubMed
The volume of published literature located. Full marks at fifty or more publications.
Mean assayed purity 99.2% across 4 certificates
Average assayed purity on the certificates published by vendors that carry this compound. Full marks at 99.5%+, nothing at 95% or below.
±1.10 pts purity across lots, mean label deviation 16.6%
How tightly assayed purity and labeled-versus-actual mass hold across different lots. Rewards reproducible manufacturing.
14 of 14 listing vendors publish an accessible certificate policy
Whether the vendors carrying this compound publish per-lot certificates anyone can read without an account.
4 of 4 certificates from a recognised independent lab
Share of certificates issued by a recognised third-party testing lab rather than an unnamed or self-named one.
What is LL-37?
A human cathelicidin-derived antimicrobial peptide studied for antimicrobial activity, immune modulation and wound healing.
Studied in published research for antimicrobial activity and wound healing.
Regulatory status
Labeled by vendors for laboratory research use only. Not approved as a medicine in the United States, United Kingdom, or European Union.
What the research examines
The areas of published research this compound appears in. These describe what the literature has studied — never a claim of benefit, effect or suitability for any use.
Published research
Published work is largely preclinical, in cell and animal models of infection and wound repair. PepIndex does not evaluate clinical significance and does not describe administration.
- The LL-37 domain: A clue to cathelicidin immunomodulatory response? — Peptides (2023)
Peer-reviewed article indexed in PubMed, published in Peptides (2023).
- LL-37: Cathelicidin-related antimicrobial peptide with pleiotropic activity — Pharmacological reports : PR (2016)
Peer-reviewed article indexed in PubMed, published in Pharmacological reports : PR (2016).
- Antimicrobial Peptides of the Cathelicidin Family: Focus on LL-37 and Its Modifications — International journal of molecular sciences (2025)
Peer-reviewed article indexed in PubMed, published in International journal of molecular sciences (2025).
- Rosacea: Pathogenesis and Therapeutic Correlates — Journal of cutaneous medicine and surgery (2024)
Peer-reviewed article indexed in PubMed, published in Journal of cutaneous medicine and surgery (2024).
- Unique features of human cathelicidin LL-37 — BioFactors (Oxford, England) (2015)
Peer-reviewed article indexed in PubMed, published in BioFactors (Oxford, England) (2015).
- The roles of cathelicidin LL-37 in immune defences and novel clinical applications — Current opinion in hematology (2009)
Peer-reviewed article indexed in PubMed, published in Current opinion in hematology (2009).
- The human cathelicidin hCAP18/LL-37: a multifunctional peptide involved in mycobacterial infections — Peptides (2010)
Peer-reviewed article indexed in PubMed, published in Peptides (2010).
- The human cathelicidin LL-37: a multifunctional peptide involved in infection and inflammation in the lung — Pulmonary pharmacology & therapeutics (2005)
Peer-reviewed article indexed in PubMed, published in Pulmonary pharmacology & therapeutics (2005).
PepIndex describes what literature exists. We do not interpret it, assess clinical significance, or publish quantities, protocols or instructions for use.