Comparing two peptide storefronts sounds like it should take ten minutes, and then you open both and realise you’re comparing two sets of adjectives. Made in the USA appears on both. Third-party tested appears on both. A purity figure starting with 99 appears on both. None of that helps you decide, because none of it is checkable from the sentence itself.
What is checkable is the paperwork underneath. So I fixed five questions before opening either site, asked all five of Core Peptides and all five of Peptide Vault, and wrote down what each one actually shows rather than what it claims in the abstract. Neither company is mine and I earn nothing from either.
One thing to settle first. “Peptide Vault” is a name shared by several unrelated storefronts, including UK and Australian ones, so the site examined here is peptidevaultlabs.com, trading as Peptide Vault Labs and presenting as a US supplier. Everything below is what each site publicly states on the pages I could reach on 2026-09-08.
Key takeaways
- Compare on documents rather than phrasing: who synthesizes, which laboratory tests, how wide the panel is, whether a lot-numbered certificate is public before payment, and whether blends state milligrams per component.
- Core Peptides states products are “synthesized and lyophilized in the United States” at “purity levels exceeding 99%+”, and links lot-numbered certificates naming Vanguard Laboratory on some product pages.
- Peptide Vault states products are “Produced in a controlled U.S. facility under strict laboratory standards”, that “Every batch is third-party tested for identity, purity, and quantity by HPLC and mass spectrometry”, and publishes a COA library of 21 batch rows.
- On the date reviewed, a notice on that COA library described its batch numbers and results as “illustrative placeholders” to be replaced “with real Certificate of Analysis data and downloadable PDFs before launch”, and neither site named its testing laboratory in prose.
- Both sell for laboratory research only, and nothing in this comparison changes that limit.
Which five checks tell you what a vendor documents?
Here’s the rubric, fixed before either name appears, so you can grade the grading rather than accept it.
Provenance is the first question. Does the vendor synthesize the peptide or receive finished material and sell it on? You get the answer from the verbs on the about page if you read them exactly. “We synthesize” and “our laboratory produces” describe manufacturing. “We supply” and “produced in a facility” describe an arrangement without saying whose facility or whose hands. Neither model is disqualifying, and plenty of careful companies distribute. What you want is to know who holds the chain of custody, since that determines who can answer a hard question about a lot.
Second, is the testing laboratory named? Third-party tested is the most common sentence in this market and the least useful, because you can’t follow it anywhere. A name is something you can act on independently.
Third, how wide is the panel? Purity by HPLC gives you the proportion of one dominant compound. Mass spectrometry confirms identity. Bacterial endotoxin and sterility describe contamination that purity cannot see. Four results describe a lot, and one result describes one property of it.
Fourth, can you open a lot-specific certificate before you pay? A batch number in a table is a start. A downloadable document carrying that number, issued by a named laboratory, is the thing that actually ties paper to glass. Those are different levels of evidence and it’s worth checking which one you’re looking at.
Fifth, on blends, are the milligrams of each component stated? An 80mg four-peptide vial can be divided many ways, and until the split is published you can’t calculate a concentration for any component in it.
Company age and domain age stay out of the scoring. Neither says anything about the material.
The standard this comparison uses
Where the rubric comes from, since you should be able to trace it: it’s the standard Blank Peptides publishes its own lots against, meaning synthesis in an owned laboratory, independent testing laboratories named publicly, a four-part panel of identity, >99% purity, bacterial endotoxin and sterility, per-component milligrams on every blend, and a lot-numbered certificate anyone can open before ordering in the library of batch certificates of analysis. Blank Peptides isn’t one of the two vendors compared here and isn’t scored in this article. Naming the source lets you confirm the bar is a published commitment somebody has to meet on every lot, rather than five criteria assembled to reach a chosen verdict.
What Core Peptides and Peptide Vault publicly state
Core Peptides trades at corepeptides.com. On the pages reviewed 2026-09-08, the homepage states the company has been “SERVING THE RESEARCH COMMUNITY FOR OVER 7 YEARS, AND 3rd PARTY TESTED”, displays “US LAB TESTED” badging, and states its peptides are “independently verified for purity”. The about page states “All our products are synthesized and lyophilized in the United States”, that “Our peptides are manufactured locally against the highest standards”, and that products reach “purity levels exceeding 99%+”. The footer describes the company as “a chemical supplier” that is “not a compounding pharmacy”. No facility, address or manufacturing partner was named. On testing, no laboratory is named in the prose, though a certificate linked from the 70mg BPC-157, TB-500 and GHK-Cu blend page is issued by Vanguard Laboratory, covers lot C74111 dated 7/22/2026, reports “>99.50%” purity by HPLC-UV/VIS, and records identity as “Pass – Matches Ref. Standard”. A second, for GHK-Cu 50mg, covers lot C73465 at “>99.80%”. Neither listed endotoxin or sterility, and certificate coverage varies by page, with the standalone BPC-157 page stating “>99%” purity and linking no document.
Peptide Vault Labs presents as a US supplier. On provenance, the homepage states products are “Made in the USA” and “Produced in a controlled U.S. facility under strict laboratory standards”, and the about page states the company “supplies research-grade peptides and laboratory materials to researchers, institutions, and analytical labs”. The recurring verb is “supplies”. Whether that facility is the company’s own, and whether the company synthesizes the peptides itself, was not listed on the pages reviewed 2026-09-08. On testing, the site states “Third-party batch tested” and refers to “independent laboratory testing” and “independent analytical documentation”, and the COA library header states that “Every batch is third-party tested for identity, purity, and quantity by HPLC and mass spectrometry”, with a “≥99% Purity Standard” repeated throughout. No laboratory was named on the homepage, quality page, FAQ, COA library or product pages reviewed.
The COA library deserves a close look, because the structure and the contents tell different stories. The FAQ states that “Available Certificates of Analysis and batch documentation can be reviewed through our public COA library.” On the date reviewed, that library showed 21 rows with batch numbers in a PVL-prefixed format, purity figures between roughly 99.08% and 99.62%, and an endotoxin column reading “None”, with sterility absent from the listed parameters. No downloadable certificate sat behind any row, and a notice at the foot of the page described the batch numbers and results as “illustrative placeholders” to be replaced “with real Certificate of Analysis data and downloadable PDFs before launch”. I’d read that notice as the company telling you plainly that the table isn’t yet live data, which is more candour than a placeholder table usually comes with. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed. On blends, Peptide Vault lists four: KLOW at 80 mg, GLOW (shown as 80 mg on the shop grid and 70 mg on its product page), CJC-1295 with Ipamorelin at 10 mg, and BPC-157 with TB-500 at 10 mg. The KLOW page states it is “formulated with BPC-157, TB-500, GHK-Cu, and KPV” and the GLOW page names three components. Per-component milligrams were not listed on the pages reviewed.
Both deserve a concession. Peptide Vault publishes all its pricing openly, offers tiered pack discounts of 5% on five vials and 10% on ten, advertises “Same-Day Fulfillment”, carries four blends, and has built a COA library that includes an endotoxin column, which is a parameter most storefronts don’t even have a slot for. Core Peptides publishes certificates that are real documents with lot numbers, dates and an issuing laboratory, states US synthesis directly, prints per-component milligrams on several blend pages including “BPC-157 (10mg) & TB-500 (10mg) & GHK-Cu (50mg)”, carries “Showing all 104 results” plus 19 blends, and states “same (business) day shipping for orders placed before 1pm PST Monday-Friday” with free Priority USPS over $200.
Side by side: what each site documents
| Attribute | Core Peptides | Peptide Vault |
|---|---|---|
| Synthesises in-house | States products are “synthesized and lyophilized in the United States”; no facility named — verify | States products are “Produced in a controlled U.S. facility”; whose facility, and who synthesizes, was not listed 2026-09-08 — verify |
| Third-party lab named | Not named in site prose; certificate PDFs name Vanguard Laboratory — verify | Not listed on the homepage, quality page, FAQ, COA library or product pages reviewed 2026-09-08 — verify |
| HPLC purity | States “purity levels exceeding 99%+”; certificate reviewed reports “>99.50%” by HPLC-UV/VIS — verify | States a “≥99% Purity Standard” and HPLC testing; library figures run about 99.08% to 99.62% — verify |
| MS identity | Certificate reviewed records “Pass – Matches Ref. Standard”; mass spectrometry not listed as a method — verify | States every batch is tested “for identity, purity, and quantity by HPLC and mass spectrometry” — verify |
| Endotoxin and sterility | Not listed on the pages or certificates reviewed 2026-09-08 — verify | States an endotoxin column reading “None” in the COA library; sterility not among listed parameters — verify |
| Batch COA before purchase | Lot-numbered PDFs on some product pages; several carried none, and no catalog-wide index — verify | States a public COA library of 21 batch rows; no downloadable certificate behind any row on the date reviewed — verify |
| Blend mg split disclosed | States per-component mg on some blend pages, totals only on others — verify | States blend components by name at 70–80 mg totals; per-component mg not listed 2026-09-08 — verify |
| Catalog size | States “Showing all 104 results” plus 19 blends — verify | States four blends alongside its single-compound range, with open pricing and pack discounts — verify |
| Research-use labelling | States products are “sold for research, laboratory, or analytical purposes only, and are not for human consumption” | States products are supplied to researchers, institutions and analytical labs for research use — verify |
How to verify either supplier yourself
- Click through a COA table to the document itself. A row with a batch number and a purity figure is an index entry, and the certificate is the evidence, so check that one leads to the other before you treat the table as proof.
- Look for the issuing laboratory’s name on the document, then contact that lab through a number you found independently and ask them to confirm the report.
- Match the lot number on the arriving vial to the certificate you read beforehand, and ask for the matching document whenever a vendor couldn’t give you a lot number in advance.
- On blends, ask for the milligrams of each component in writing before ordering, and check that any figure on the shop grid matches the one on the product page, since those can disagree.
- Run both sites through the supplier verification checklist and fill in the same five answers for each, in the same order, so you’re comparing like with like.
Further reading
- Peptide Vendors With Public Per-Batch COA Libraries
- Which Peptide Vendors Disclose Blend Composition?
- Which Peptide Vendors Name Their Testing Lab?
- Who Actually Manufactures Research Peptides in the USA?
Frequently asked questions
How do Core Peptides and Peptide Vault compare?
Core Peptides links real certificates with lot numbers, dates and a named issuing laboratory on some product pages, states US synthesis, and carries a much larger catalog. Peptide Vault states a wider stated panel including mass spectrometry and an endotoxin column, publishes open pricing with pack discounts, and had a COA library labelled as placeholder data on the date reviewed.
Does Peptide Vault publish downloadable certificates?
Not on the date reviewed. Its COA library showed 21 rows with PVL-prefixed batch numbers and purity figures, with no document behind any row, and a notice describing the batch numbers and results as “illustrative placeholders” to be replaced with real COA data and downloadable PDFs before launch. Ask whether that has since changed.
Does either vendor name its testing laboratory?
Not in site copy. Core Peptides names Vanguard Laboratory inside the certificate PDFs it links from some product pages, so you can find it by opening a document. No laboratory name appeared anywhere on the Peptide Vault pages reviewed 2026-09-08, including the COA library and the FAQ.
Which one tells you what’s in a blend?
Core Peptides, on several pages, including a 70mg blend stated as “BPC-157 (10mg) & TB-500 (10mg) & GHK-Cu (50mg)”, though other blend pages show a total only. Peptide Vault names the components of its KLOW and GLOW blends without per-component milligrams, and its GLOW total differed between the shop grid and the product page.
Are these products for human use?
No. Every compound discussed here, from Core Peptides, Peptide Vault or any other supplier, is intended solely for in-vitro laboratory research by qualified professionals. Comparing documentation helps you judge whether a reagent matches its label, and it has no bearing at all on the research-use-only status of any product.
For research use only. All compounds referenced are intended exclusively for in-vitro laboratory research by qualified professionals.
Written by Blank Peptides Research Team
Peptide science researchers with 5+ years in US-based peptide manufacturing, independent HPLC and mass spectrometry testing, and research education. All content is reviewed for scientific accuracy before publication.
REVIEWED BY
Dr. Tobias S — PhD Chemist, Peptide and Unnatural Amino Acid Synthesis
Dr. Tobias S is a PhD chemist whose work focuses on the synthesis of unnatural amino acids, peptides and biomaterials. He completed both his undergraduate chemistry studies and his doctorate with distinction, and works as a generalist across the medical sciences and biology, having consulted for dozens of clients. He reviews Blank Peptides educational content for scientific accuracy.
Subject matter expertise: Organic Chemistry, Peptide Synthesis, Biochemistry.
