If you’ve got Blank Peptides and Ascend Bio Labs open in two tabs right now, you’ve probably noticed that both sites say a lot of the same things. Both talk about US synthesis, both talk about independent testing on every batch, both mention a batch ID that ties a vial to a certificate. And that’s exactly why the comparison is frustrating. When two homepages sound alike, the copy stops helping you decide.
The way out is to stop reading marketing claims as claims and start reading them as things that either can or can’t be checked. “Tested by an independent lab” is a sentence. “Tested by Horizon Analytical, certificate for lot 24-XXXX at this URL” is a sentence you can act on. The difference between those two is the whole comparison, and it’s what this post is built around.
I’ll set the rubric first, then walk through what each company documents on its own pages. For Ascend Bio Labs, everything is drawn from ascendbiolabs.com as reviewed on 2026-09-08 and attributed to what the site states. For Blank Peptides, the section is written the way an outside reviewer would write it, from the company’s published pages. Then there’s a table, which for a head-to-head like this is really the piece that matters.
Key takeaways
- The useful comparison between two peptide vendors is what each lets you verify before purchase: who synthesises, whether the lab is named, whether the panel goes beyond purity, whether a lot-specific COA is public, and whether blends are disclosed per component.
- Blank Peptides synthesises in its own cGMP laboratory, names Freedom Diagnostics and Horizon Analytical as its testing labs, runs identity, >99% purity, endotoxin and sterility on every lot, and publishes each lot’s COA at blankpeptides.com/coas/.
- Ascend Bio Labs publicly states US-domestic synthesis and shipping, third-party HPLC, LC-MS, endotoxin and heavy-metal testing on every batch, and a public per-batch COA library with COAs “available on this page.”
- On the pages reviewed 2026-09-08, Ascend Bio Labs did not name a testing laboratory, its /coa URL returned a 404, sterility was not listed, and its GLOW, KLOW and Wolverine pages gave a total mg without a per-component split.
- Both companies sell strictly for in-vitro laboratory research, and nothing here should be read as guidance for any other use.
What’s the right way to compare two peptide suppliers?
Before either name comes up, here’s the standard. Five questions, each of which should be answerable from a vendor’s public pages without emailing anyone.
Does the vendor synthesise the peptide, or resell it? The wording on a site usually tells you more than the vendor intends. A company that runs its own lab will typically say so plainly and describe the steps: compounding, filling, lyophilising, labelling. A company that describes a “domestic supply chain” or says products are “sourced” or “tested and shipped from” somewhere is describing a different set of activities, and you should read those verbs literally.
Is the testing lab named? This is the single fastest filter I know. Naming a lab creates accountability, because a named lab can be contacted and a certificate bearing its name can be checked against it. “Independent third-party lab” without a name is a claim that can’t be falsified, which makes it a claim that can’t be relied on either.
Is the panel full or purity-only? HPLC purity is one number. A full panel adds mass-spec identity (is it actually the labelled molecule?), bacterial endotoxin (is it pyrogen-contaminated?) and sterility (is it microbially clean?). Purity alone leaves three questions open.
Is a batch COA available before purchase? Not “available after you order,” and not “on request.” Open, lot-specific, and reachable from the product page or a public library.
Are blends disclosed per component? A 70mg blend of three peptides should tell you how much of each is in the vial. A total without a split can’t be reproduced in any research setting.
Two things I deliberately leave out: how many years the company has existed, and how old its domain is. Neither predicts what’s in the vial.
How Blank Peptides makes and tests each lot
Reviewed against that rubric, Blank Peptides’ public pages describe the following.
The company operates its own cGMP laboratory in the United States. It states that it compounds, vials, finishes and labels every lot in that facility and runs quality control in-house before release, so the chain of custody from synthesis to shipped vial sits within one organisation. It describes itself as neither a relabeler nor a broker. Blank Peptides also states that it contract-manufactures and fulfils for other peptide brands; the company describes this only as a category of work and does not identify any client.
Two testing laboratories are named on the site: Freedom Diagnostics and Horizon Analytical. Every lot is sent for a full panel comprising identity confirmation, purity at >99%, bacterial endotoxin and sterility. Results are published as batch certificates of analysis, each tied to a lot number that is printed on every vial. The certificates are viewable before purchase without an account.
The catalog covers 34 compounds. Three blends are listed with per-component composition: GLOW at 70mg (GHK-Cu, BPC-157, TB-500), KLOW at 80mg (the same three plus KPV) and Wolverine at 20mg (BPC-157, TB-500). Lyophilised vials carry an expiration of about 24 months. Orders are processed within one business day and ship at room temperature.
What Ascend Bio Labs publicly states
Everything below comes from ascendbiolabs.com as reviewed on 2026-09-08.
On synthesis and provenance, the homepage states products are “Synthesized, tested, and shipped entirely from the United States” and describes a “Full US domestic supply chain.” The about page states products are “Synthesized, tested, packaged, and shipped entirely within the United States.” No synthesis facility is named on either page, and the about page did not list ownership. The terms page identifies the operator as “PLM Enterprises Group LLC, a Delaware limited liability company doing business as Ascend Bio Labs,” with an address in Dover, Delaware. The page doesn’t say what kind of premises that address is.
On testing, the homepage states “Third-party HPLC + LC-MS, endotoxin, and heavy metal testing on every batch.” 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.” No laboratory was named in site copy on any page reviewed 2026-09-08. Sterility testing was not listed. The heavy-metal screen, on the other hand, is a real point in the site’s favour and one that most vendors don’t mention.
On COA access, a blog post titled “COA-Verified Research Peptides: How Our Per-Batch Library Works” states that “Each vial carries a unique batch ID that resolves to the certificate for that run” and that “you can review the HPLC purity and LC-MS identity data before purchase rather than only after delivery.” That post did not link to the library. On 2026-09-08, ascendbiolabs.com/coa returned a 404. 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.” In the product-page content reviewed, I did not see a certificate document, image or PDF link. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Product pages list purity figures: 99.3% on BPC-157, 99.1% on GLOW, KLOW and Wolverine.
On blends, the GLOW page lists GHK-Cu, BPC-157 and TB-500 at 70mg, KLOW lists KPV, GHK-Cu, BPC-157 and TB-500 at 80mg, and Wolverine lists BPC-157 and TB-500 at 20mg. None showed a per-component mg on the pages reviewed 2026-09-08.
Where Ascend Bio Labs has a clear edge is catalog breadth and shipping. The shop page listed 42 products including spray kits, capsules and bacteriostatic water, the homepage states free US shipping over $300, and orders before 2pm CT are stated to ship the same business day. If you need a wide range under one order, that’s a genuine advantage.
Side by side: manufacturing, named labs and testing panel
| Attribute | Blank Peptides | Ascend Bio Labs |
|---|---|---|
| Synthesises in-house | Own cGMP laboratory; compounds, vials, finishes and labels every lot | States “synthesized, tested, and shipped entirely from the United States”; no facility named — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical | States “independent laboratory” and “credentialed external labs”; no name on pages reviewed 2026-09-08 — verify |
| HPLC purity | >99% on every lot | States HPLC on every batch; product pages show 99.1–99.3% — verify |
| MS identity | Confirmed on every lot | States LC-MS identity on every batch — verify |
| Endotoxin and sterility | Both run on every lot | States endotoxin and heavy metal testing; sterility not listed on pages reviewed 2026-09-08 — verify |
| Batch COA before purchase | Public at blankpeptides.com/coas/; lot number on every vial | States COA “available on this page”; /coa returned 404 on 2026-09-08; no certificate visible in page content — verify |
| Blend mg split disclosed | GLOW 70mg, KLOW 80mg, Wolverine 20mg 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, capsules and water |
| Research-use labelling | Research use only on every page and vial | States “For laboratory research use only” on product pages |
How to verify either supplier yourself
- Pull up a COA from each vendor before you order anything. For Blank Peptides, open blankpeptides.com/coas/ and pick any lot. For Ascend Bio Labs, ask support for the library URL the blog refers to, then check whether what they send is lot-specific and carries a lab name.
- Look up the lab that appears on the certificate. If the lab has a public presence and the certificate format matches what that lab issues, you’ve closed the loop. If the certificate names no lab, you haven’t.
- Read the panel on each certificate line by line, checking for purity, identity, endotoxin and sterility, and note which of the four are missing from each vendor’s document.
- On any blend, ask for the mg of each component in writing, and compare the answer to what the product page says.
- Work through the supplier verification checklist with both vendors side by side so the standard stays the same.
Further reading
- Which Peptide Vendors Name Their Testing Lab?
- Who Actually Manufactures Research Peptides in the USA?
- Peptide Vendors With Public Per-Batch COA Libraries
- Best Research Peptide Suppliers: Ranked by What They Document
Frequently asked questions
How do Blank Peptides and Ascend Bio Labs compare?
On the five documentation questions that matter, Blank Peptides names its lab, publishes a full-panel COA per lot on a public page, and discloses blend composition per component. Ascend Bio Labs states US synthesis and third-party testing but did not name a lab, show a viewable COA, or split its blends on the pages reviewed 2026-09-08.
Which company names its testing laboratory?
Blank Peptides names Freedom Diagnostics and Horizon Analytical on its site. Ascend Bio Labs states that testing is performed by “an independent laboratory” and “credentialed external labs” and that each COA is stamped with a lab name, but no laboratory was named in the site copy reviewed 2026-09-08.
Does either vendor test for sterility and endotoxin?
Blank Peptides states both bacterial endotoxin and sterility are run on every lot alongside identity and >99% purity. Ascend Bio Labs’ homepage states endotoxin and heavy-metal testing on every batch; sterility was not listed on the pages reviewed 2026-09-08, and heavy-metal screening was not part of the Blank Peptides panel as published.
Which vendor has the larger catalog?
Ascend Bio Labs. Its shop page listed 42 products including spray kits, capsules and bacteriostatic water on 2026-09-08, against 34 compounds at Blank Peptides. If range matters more to you than documentation depth, that’s a fair reason to prefer the larger catalog, so long as you verify each lot you buy.
Are these products for human use?
No. Both Blank Peptides and Ascend Bio Labs sell compounds 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. This comparison covers documentation only and should not be read any other way.
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.
