You’ve narrowed it to two vendors and you still can’t separate them. Core Peptides says USA made and third-party tested. Umbrella Labs says USA made and third-party tested. Both quote a purity figure starting with 99, both sell a BPC-157 and TB-500 blend, and both have the kind of clean product photography that tells you exactly nothing about what’s in the vial. So you open a third tab, read some forum posts, and end up more confused than when you started.
Neither of these companies is us. We make and test peptides ourselves, which means we have opinions about what good documentation looks like, but we don’t sell against either of these two and we’re not going to pretend one of them is secretly terrible so you’ll buy from someone else. What follows is a referee’s job: the same five questions put to both sites, the answers quoted from their own pages, and a table so you can see where they diverge.
Everything below reflects what was publicly readable on the pages reviewed 2026-09-08. Sites change. If you’re reading this months later, check the pages yourself before you act on any of it.
Key takeaways
- The comparison that actually helps you is who synthesized the lot, which laboratory tested it, what the certificate covers, whether you can read that certificate before you pay, and whether blends disclose each component’s milligrams.
- Core Peptides states its products are “synthesized and lyophilized in the United States” with purity “exceeding 99%+”, and links a lot-numbered COA on some blend pages that names an outside laboratory.
- Umbrella Labs publishes a category-organized COA index covering seventy-plus peptides, names laboratories on those documents, and prints per-component milligrams in its blend product titles.
- Bacterial endotoxin and sterility results were not listed on the pages reviewed 2026-09-08 for either company, and neither site names its testing laboratory in the ordinary marketing prose a first-time buyer reads.
- All of this concerns research-use-only material, and nothing here is guidance on use in any person or animal.
What separates two suppliers that both claim 99% purity?
Let me set out the yardstick before either company gets measured against it, because a referee who invents the rules halfway through isn’t refereeing anything.
The first question is provenance. Does the company synthesize the material, or does it buy finished product and apply its own label? The verbs on an About page usually tell you. “We synthesize”, “our laboratory”, “our QC” point one direction. “We source”, “we supply”, “our partners” point another. Neither answer disqualifies a vendor, but a company that made the lot can tell you what happened to it between raw material and vial, while a company that bought it can only repeat what it was told.
The second question is whether the testing laboratory is named. Any site can print a badge reading third-party tested. A name is different, because you can look the laboratory up, confirm it does peptide analysis, and in principle send it your own sample.
The third is what the panel covers. HPLC purity is the number everybody quotes, and it’s a real measurement, but it only reports how much of the sample is a single substance. It says nothing about whether that substance is the right sequence, which takes mass spectrometry, and nothing at all about bacterial endotoxin or sterility. A full panel covers identity, purity, endotoxin and sterility. A purity-only certificate covers one of the four.
The fourth is whether a batch certificate is readable before purchase and tied to a lot number that also appears on the vial you receive. A certificate you can only see after paying, or one with no lot number to match against the glass, is decoration rather than evidence.
The fifth is blend composition. A blend advertised only by total milligrams can’t be reproduced by anyone, including the person who bought it, so a supplier that takes its own documentation seriously prints the split per component.
Company age and domain age are deliberately absent from that list. Neither tells you anything about the lot sitting on your bench.
Where this standard comes from
For transparency about who wrote this: the five questions above are the standard Blank Peptides publishes its own lots against, and its batch certificates of analysis are public if you want to see what a full-panel document looks like before judging anyone else’s. That’s the only reason it appears here. The rest of this article is about the two companies in the title, and the grading below is meant to be the same grading either of them would get from a reviewer with no stake in the outcome.
What Core Peptides and Umbrella Labs publicly state
Core Peptides sells at corepeptides.com. On the pages reviewed 2026-09-08, the homepage carries “3rd PARTY TESTED” and “US LAB TESTED” badges, states “Serving the research community for over 7 years”, and describes “U.S. lab-tested peptides” that are “independently verified for purity”. The About page states that “All our products are synthesized and lyophilized in the United States, with purity levels exceeding 99%+” and that “Our peptides are manufactured locally against the highest standards for synthesis, undergoing rigorous quality control measures to ensure their purity, stability, and consistency”. The same page describes the company as “a chemical supplier” and states it is “not a compounding pharmacy or chemical compounding facility” and “not an outsourcing facility”.
On documentation, Core Peptides links a Certificate of Analysis PDF from its 70mg BPC-157, TB-500 and GHK-Cu blend page. That PDF names Vanguard Laboratory, lists an HPLC-UV/VIS method, reports purity of “>99.50%”, records identity as “Pass – Matches Ref. Standard”, and carries lot C74111 dated 7/22/2026. The KLOW 80mg page also links a certificate. The single-compound BPC-157 page states “Purity: >99%” and showed no certificate link on the page reviewed 2026-09-08. Blend disclosure is mixed: the 70mg page states “BPC-157 (10mg) & TB-500 (10mg) & GHK-Cu (50mg)”, while the KLOW page lists four components without per-component amounts.
Umbrella Labs sells at umbrellalabs.is. On the pages reviewed 2026-09-08, the homepage states “USA MADE • ≥99% PURITY” and describes its process this way: “We employ industry-leading High Performance Liquid Chromatography and Liquid/Gas Chromatography-Mass Spectrometry in our manufacturing pipeline”, with “routine analyses conducted in a CLIA environment using a flexible range of Thermo Scientific and Agilent modalities”. The site also states that “Umbrella Labs are the only supplier of SARMs & Peptides with third-party purity validation from analytical chemists credentialed by the National Certification Commission in Chemistry and Chemical Engineering (NCCCCE)”.
Its certificate hub splits into “View SARMs COA’s”, “View Peptides COA’s”, “View Nootropics COA’s” and “View Research Chemicals COA’s”. The peptides index lists more than seventy compounds with linked documents, and the laboratories named across those documents include MZ BioLabs and Vanguard Laboratory. Its blend pages state splits in the product title itself, for example “GHK-Cu (50mg)/TB-500 (10mg)/BPC-157 (10mg)/KPV(10mg) Blend Peptide 80mg Vial” at “≥99% Pure (LC-MS)” for $129.99, with a dated certificate file attached. Products carry the statement “All products are for laboratory developmental research USE ONLY. Products are not for human consumption.”
What neither site listed on the pages reviewed 2026-09-08: a named manufacturing facility, bacterial endotoxin results, or sterility results. Core Peptides names a laboratory only inside a linked PDF rather than in its site prose. Umbrella Labs describes credentials and instrument brands in its prose and puts laboratory names on the documents themselves. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Each company has a real strength here. Core Peptides publishes the larger single-compound catalog, stating “Showing all 104 results” plus a separate blend range, and its shipping page states “same (business) day shipping for orders placed before 1pm PST Monday-Friday” with “Free Priority USPS shipping on orders over $200 within the US”. Umbrella Labs has the more complete public certificate library of the two, organized by product category and covering the majority of its peptide range rather than a handful of pages, and its blend titles disclose every component’s milligrams without you having to ask.
Side by side: what each site documents
| Attribute | Core Peptides | Umbrella Labs |
|---|---|---|
| Synthesises in-house | States products are “synthesized and lyophilized in the United States”; facility not listed — verify | States “USA MADE” and describes a “manufacturing pipeline”; facility not listed — verify |
| Third-party lab named | States “3rd party tested”; one linked COA names Vanguard Laboratory, site prose does not — verify | States NCCCCE-credentialed validation; COA index shows MZ BioLabs and Vanguard Laboratory — verify |
| HPLC purity | States “Purity: >99%”; one COA reports “>99.50%” by HPLC-UV/VIS — verify | States “≥99% PURITY” and cites HPLC in its stated process — verify |
| MS identity | COA reviewed records identity by reference-standard match; MS method not listed — verify | States LC/GC-mass spectrometry in its process, and a blend page states “≥99% Pure (LC-MS)” — verify |
| Endotoxin and sterility | Not listed on the pages reviewed 2026-09-08 — verify | Not listed on the pages reviewed 2026-09-08 — verify |
| Batch COA before purchase | Some blend pages link a lot-numbered PDF; the BPC-157 page reviewed showed none — verify | States a category COA index covering 70+ peptides, linked publicly — verify |
| Blend mg split disclosed | States splits on some blends; KLOW lists components without amounts — verify | States per-component milligrams in blend product titles — verify |
| Catalog size | States “Showing all 104 results” plus a blend range | States “50+ Sarms” plus peptides, nootropics and research chemicals — verify |
| Research-use labelling | States products are “not for human consumption” on pages reviewed | States products are “not for human consumption” on pages reviewed |
How to verify either supplier yourself
- Open the product page for the exact compound and size you intend to order, not the homepage, and look for a certificate on that page. Homepage badges tell you what a company wants to be known for; product pages tell you what it will actually hand over.
- Read the certificate’s method lines rather than its headline number. You want an HPLC line for purity, a mass spectrometry line for identity, and separate results for bacterial endotoxin and sterility. Where a line is missing, email support and ask whether that test exists for the lot you’re buying.
- Write down the lot number on the certificate and compare it against the lot printed on the vial when the package arrives. A vial with no lot number, or a lot that doesn’t match the paperwork, is the thing worth chasing before you use the material.
- Look up whichever laboratory the certificate names. A working analytical laboratory has an address, a phone number and a published list of services, and if you can’t find one, ask the vendor for the laboratory’s contact details.
- Put both companies through the supplier verification checklist so each answers the same questions in the same order.
Further reading
- Which Peptide Vendors Name Their Testing Lab?
- Peptide Vendors With Public Per-Batch COA Libraries
- Which Peptide Vendors Disclose Blend Composition?
- Best Research Peptide Suppliers: Ranked by What They Document
Frequently asked questions
How do Core Peptides vs Umbrella Labs compare on documentation?
Umbrella Labs publishes the broader certificate library, indexed by category across seventy-plus peptides, with laboratory names on the documents. Core Peptides links certificates on some blend pages, including one naming Vanguard Laboratory with lot C74111. On the pages reviewed 2026-09-08, neither company listed bacterial endotoxin or sterility results, and neither named a laboratory in its ordinary site prose.
Does either company name its testing laboratory?
On the documents, yes for both. Umbrella Labs’ peptide certificate index shows MZ BioLabs and Vanguard Laboratory across its files, and one Core Peptides certificate names Vanguard Laboratory. In the marketing prose that a first-time visitor reads, neither names a laboratory. That gap matters mainly because most buyers never open the PDF, and the badge on the homepage is what they remember.
Which one discloses blend composition more consistently?
Umbrella Labs, on the pages reviewed 2026-09-08. Its blend titles state each component’s milligrams, as in the 80mg GHK-Cu, TB-500, BPC-157 and KPV vial. Core Peptides states the split on its 70mg blend page but lists KLOW’s four components without amounts. For any blend page showing only a total, ask for the per-component breakdown in writing before ordering.
Which has the larger catalog?
Core Peptides states “Showing all 104 results” on its peptide catalog page plus a separate blend range, which is the deeper single-compound selection of the two. Umbrella Labs spans several product classes beyond peptides, including SARMs, nootropics and research chemicals, so the honest answer depends on whether you need range within peptides or range across categories.
Are these products for human use?
No. Both companies label their material for laboratory research only, and Core Peptides states products are “not for human consumption” while Umbrella Labs states they are “for laboratory developmental research USE ONLY”. This article compares published documentation and manufacturing language, and nothing in it is guidance on dosing or on use in any person or animal.
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.
