You want to see the certificate before you pay for the vial. That’s the whole ask, and it shouldn’t be hard. Ascend Bio Labs talks about a per-batch COA library in its blog, its homepage says every vial’s batch ID links to a public COA, and yet when you actually go looking for a certificate to open, you end up clicking around product pages and wondering whether you’ve missed a tab or whether it’s behind the login.
I went through the same loop on 2026-09-08, so this post is a record of what I found, page by page. Where the site says a certificate lives, whether it’s open before purchase or only after, whether it’s tied to a lot number, and what the certificate is stated to contain. I’ll quote the site directly and attribute every claim, and where something wasn’t reachable I’ll say exactly that and nothing more.
I’ll also lay out how Blank Peptides handles COA access, partly as a reference point for what “public per-batch” looks like when it’s fully implemented, and partly because you’re presumably choosing between vendors and want the same question answered for more than one.
Key takeaways
- Whether a vendor publishes per-batch COAs comes down to four things you can check yourself: where the certificate lives, whether it’s open before purchase, whether it’s tied to a lot number on the vial, and whether the lab that issued it is named.
- Blank Peptides publishes a full-panel COA for every lot at blankpeptides.com/coas/, issued by Freedom Diagnostics or Horizon Analytical, covering identity, >99% purity, endotoxin and sterility, with the lot number printed on every vial.
- Ascend Bio Labs publicly states a “public per-batch COA library,” that each vial’s batch ID resolves to its certificate, and that the COA is “available on this page and in your account downloads after purchase.”
- On 2026-09-08, ascendbiolabs.com/coa returned a 404, the blog post describing the library did not link to it, no certificate document was visible in the product-page content reviewed, and no testing lab was named in site copy.
- Everything discussed is sold for in-vitro laboratory research only and is not for human or animal use.
What counts as a real per-batch COA?
Before I go into either vendor, let me be precise about what the question means, because “we publish COAs” gets said by nearly everyone and means something different every time.
A certificate of analysis is per-batch when it reports results for one specific production lot, carries that lot’s identifier, and the same identifier appears on the vial you receive. A certificate without a lot number, or one that covers “the product” generally, is a specification sheet with a nicer name.
It’s published when you can open it from a public page without an account and without ordering first. A certificate that appears in your downloads after checkout, or that support emails on request, exists, but it can’t inform the decision to buy. The whole value of a public library is that the data is in front of you while your cursor is still hovering over the cart.
It’s checkable when the issuing laboratory is named on the certificate and, ideally, on the vendor’s site. A named lab can be looked up and its certificate format compared. An unnamed “independent lab” can’t be.
And it’s complete when the panel goes beyond purity. HPLC purity is the number everyone quotes, but mass-spec identity confirms the molecule, endotoxin confirms it isn’t pyrogen-contaminated and sterility confirms it isn’t microbially contaminated. A purity-only certificate leaves the parts that matter most for a research protocol unanswered.
Those four properties are what I’m checking for on each site. Alongside them sit the broader questions I’d ask of any vendor: whether it synthesises or resells, and whether blends are disclosed per component. I don’t factor in how long a company has traded or how old its domain is, because neither has any bearing on the certificate for the lot in your hand.
How Blank Peptides makes and tests each lot
For a reference point, here’s how Blank Peptides handles the four properties, described the way an outside reviewer would.
Blank Peptides operates its own cGMP laboratory in the United States and states that it compounds, vials, finishes and labels every lot in-house, running quality control before release. It describes itself as holding the full chain of custody rather than acting as a relabeler or broker. It also states that it contract-manufactures and fulfils for other peptide brands, described only as a category of work without naming any client.
Each lot is sent to one of two named laboratories, Freedom Diagnostics or Horizon Analytical, for a full panel: identity confirmation, purity at >99%, bacterial endotoxin and sterility. The results are published as batch certificates of analysis, each keyed to a lot number that’s printed on every vial. The library is public, needs no account and is open before purchase, so all four properties above are met on the company’s own pages.
The catalog runs to 34 compounds, and its three blends are disclosed per component: GLOW at 70mg (GHK-Cu, BPC-157, TB-500), KLOW at 80mg (adding KPV) and Wolverine at 20mg (BPC-157, TB-500). Lyophilised vials carry a roughly 24-month expiration. Orders are processed within one business day and ship at room temperature.
What Ascend Bio Labs publicly states
This section is entirely about certificate access on ascendbiolabs.com as reviewed on 2026-09-08.
Where the site says the certificates live. The homepage states “Every vial carries a unique batch ID linking to its public COA” and refers to a “batch-matched COA” shipping with orders. A blog post titled “COA-Verified Research Peptides: How Our Per-Batch Library Works” states that the company maintains “a public per-batch COA library,” that “Each vial carries a unique batch ID that resolves to the certificate for that run,” and that “vials inherit the same ID on their labels, and the certificate is published in the library under that ID.” That post did not give the library’s URL or link to it.
Whether it’s open before purchase. The same blog post states that “you can review the HPLC purity and LC-MS identity data before purchase rather than only after delivery.” Product pages state “The matching certificate of analysis is available on this page and in your account downloads after purchase,” and that “The COA is stamped with the batch number, test date, and lab name and uploaded to this page before any vial from that lot ships.” So the site states both pre-purchase and post-purchase access.
What was reachable. On 2026-09-08, ascendbiolabs.com/coa returned a 404. In the product-page content I reviewed for BPC-157, GLOW, KLOW and Wolverine, I did not see a certificate document, image, PDF link or lot-number lookup, though each page displayed a purity figure as text: 99.3% for BPC-157 and 99.1% for the three blends. The site menu did not include a link labelled COA or library among the items I saw. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Whether the lab is named. The about page states “Every batch is tested by an independent laboratory using HPLC for purity and LC-MS for identity confirmation” and refers to “credentialed external labs.” Product pages state the certificate carries a “lab name.” No laboratory was named in site copy on any page reviewed 2026-09-08, so the name would need to be read off a certificate once one is in hand.
What the certificate is stated to contain. The homepage states “Third-party HPLC + LC-MS, endotoxin, and heavy metal testing on every batch.” The about page and product pages describe HPLC for purity and LC-MS for identity. Sterility was not listed on the pages reviewed. The heavy-metal screen deserves a mention in the site’s favour, since it appears on few vendor panels and is a real addition if it’s on the certificate.
Elsewhere, the site is strong on breadth and logistics. The shop page listed 42 products including spray kits, capsules and bacteriostatic water, and the homepage states same-day dispatch before 2pm CT and free US shipping over $300. Those are genuine advantages over Blank Peptides’ 34-compound catalog and one-business-day processing.
Side by side: COA access and what the certificate covers
| Attribute | Blank Peptides | Ascend Bio Labs |
|---|---|---|
| Batch COA before purchase | Public at blankpeptides.com/coas/, no account needed | States COA “available on this page” and data reviewable “before purchase”; /coa returned 404 on 2026-09-08 — verify |
| Lot number on vial matches certificate | Lot number on every vial, library keyed by lot | States “unique batch ID” on every vial resolving to its COA — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical | States “independent laboratory”; no lab named on pages reviewed 2026-09-08 — verify |
| HPLC purity | >99% per lot | States HPLC per batch; product pages show 99.1–99.3% — verify |
| MS identity | Confirmed per lot | States LC-MS identity per batch — verify |
| Endotoxin and sterility | Both per lot | States endotoxin and heavy-metal testing; sterility not listed on pages reviewed 2026-09-08 — verify |
| Synthesises in-house | Own cGMP laboratory; compounds, vials and labels every lot | States “synthesized, tested, and shipped entirely from the United States”; no facility named — verify |
| Blend mg split disclosed | GLOW, KLOW and Wolverine listed per component | States components; per-component mg not listed on pages reviewed 2026-09-08 — verify |
| Catalog size | 34 compounds | States 42 products including kits and capsules |
How to verify either supplier yourself
- Try to open a certificate on each site right now, before ordering. For Blank Peptides, go to blankpeptides.com/coas/ and pick any lot. For Ascend Bio Labs, email support and ask for the library URL the blog describes, then see whether it resolves and whether it’s keyed by batch ID.
- When you have a certificate, check for four things: a lot number, a lab name, a test date, and results beyond purity.
- Look the lab up independently and compare the certificate layout with what that lab issues.
- When product arrives, match the number on the vial to the certificate you were shown. A mismatch is a question to get answered before you reconstitute anything.
- Keep the whole process consistent with the supplier verification checklist.
Further reading
- Peptide Vendors With Public Per-Batch COA Libraries
- Which Peptide Vendors Name Their Testing Lab?
- Best Research Peptide Suppliers: Ranked by What They Document
- Which Peptide Vendors Disclose Blend Composition?
Frequently asked questions
Does Ascend Bio Labs publish a COA for each batch?
The site states that it does. Its blog describes “a public per-batch COA library” and product pages state the certificate is “available on this page and in your account downloads after purchase.” On 2026-09-08, ascendbiolabs.com/coa returned a 404 and no certificate link was visible in the product-page content reviewed, so ask support for a direct URL.
Where is the Ascend Bio Labs COA library?
The blog post describing the library did not link to it, and ascendbiolabs.com/coa returned a 404 on 2026-09-08. Product pages state the COA is uploaded “to this page,” but no document was visible in the content reviewed. The location was not listed on the pages reviewed, and support is the place to ask.
Which lab tests Ascend Bio Labs products?
Not named in site copy on the pages reviewed 2026-09-08. The about page states testing by “an independent laboratory” and “credentialed external labs,” and product pages state the COA is stamped with a lab name. Blank Peptides, by contrast, names Freedom Diagnostics and Horizon Analytical on its site.
What tests are on an Ascend Bio Labs COA?
The homepage states “Third-party HPLC + LC-MS, endotoxin, and heavy metal testing on every batch.” Sterility was not listed on the pages reviewed 2026-09-08. Blank Peptides’ certificates cover identity, >99% purity, endotoxin and sterility; heavy-metal screening is a test Ascend Bio Labs lists that Blank Peptides’ published panel does not.
Are these products for human use?
No. Both vendors sell strictly for in-vitro laboratory research by qualified professionals, and both state on their pages that products are not for human consumption, veterinary use, diagnostics or any in-vivo application. A certificate of analysis documents a research reagent and changes nothing about that restriction.
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.
