You’ve got two tabs open. One is Blank Peptides, one is BioLongevity Labs, and both say the right things about purity and third-party testing, so you’re stuck trying to work out which set of claims you can actually check. That’s the frustrating part of buying research peptides in 2026: the marketing has converged, and the differences that matter are buried in the verbs on the about page and the fine print on the certificate.
This is a head-to-head on the things you can verify from outside. I’m going to compare the two on provenance, whether the testing lab is named, whether the panel is full or purity only, whether a lot-tied COA is visible before purchase, and whether blend splits are disclosed. The table in the middle is the centrepiece, and the sections around it explain where each cell came from.
One thing to say plainly: Blank Peptides publishes this site, so read the Blank Peptides section as a company describing itself, and read the BioLongevity Labs section as a set of quotations from their pages on 2026-09-08. I’ve tried to hold both to the same rubric, and where BioLongevity Labs has the better position, I say so.
Key takeaways
- The comparison that matters is documentation you can trace to a specific lot, not badges, and both suppliers should be held to the same five questions.
- Blank Peptides synthesizes its 34 compounds in its own cGMP laboratory and tests every lot at Freedom Diagnostics and Horizon Analytical for identity, >99% purity, bacterial endotoxin and sterility, with lot-tied certificates public before purchase.
- BioLongevity Labs publicly states that it manufactures in U.S.-based GMP-certified facilities using solid-phase synthesis with qualified partners, tests every batch at three named labs, and makes all COAs available before purchase.
- On the pages reviewed 2026-09-08, whether BioLongevity Labs operates its synthesis facility wasn’t stated, and a sterility result wasn’t among the certificates shown on the product pages we opened.
- Everything referenced here is for in-vitro research use only.
What should a head-to-head between peptide suppliers actually measure?
Before either name comes up, here’s the rubric, fixed in advance.
One, provenance. Does the supplier synthesize the compound or acquire it? The answer determines whether a certificate describes their process or someone else’s output. Look for active verbs with a clear subject. “We manufacture” is one thing; “synthesized in registered facilities” is grammatically true of a contract arrangement too.
Two, is the testing lab named? A vendor that names its lab has given you a claim you can check by contacting the lab. A vendor that says “third-party tested” and stops there has given you a claim you can only believe or not.
Three, is the panel full or purity only? HPLC purity is one number. Mass spectrometry confirms identity. Bacterial endotoxin by LAL and a sterility result tell you whether the material can go into a biological assay without contaminating it. A full panel is all four; a purity-only certificate has answered one.
Four, is a batch COA visible before purchase, and is it tied to a lot number you’ll find on the vial? This is what turns a certificate from a brochure into evidence.
Five, for blends, is the composition disclosed per component in milligrams? Without the split, you can’t compute a concentration for any single peptide in the vial.
There are two things I’m leaving out. Company age and domain age don’t tell you how a peptide was made, so they’re not scored. And price is a real consideration, but it’s not a documentation criterion, so I’ll mention it in passing rather than in the table.
Here’s what I mean by holding both to the same standard: for each row, Blank Peptides’ cell is a statement of what the company does, and BioLongevity Labs’ cell is what their site states or a flag to verify. You can apply exactly the same treatment to any third supplier.
How Blank Peptides makes and tests each lot
Blank Peptides operates its own cGMP laboratory in the USA and describes its process as fully in-house. Compounds are synthesized on site, lyophilized, vialed, finished and labelled there, and quality control is run inside the facility before a lot is released. The company therefore sits in the manufacturer category rather than the relabeler or broker category, and the chain of custody stays under one roof until shipment. It also states that it contract-manufactures and fulfils for other peptide brands as a category of work, without identifying those brands.
Testing is sent out to two named laboratories, Freedom Diagnostics and Horizon Analytical, and every lot gets the full panel: identity, purity at >99%, bacterial endotoxin and sterility. The results are published as batch certificates of analysis, organized by lot, and the lot number is printed on every vial so a researcher can match paper to product directly. Lyophilized material carries an expiration of about 24 months.
The catalog is 34 compounds, and each of the three blends is disclosed per component: GLOW at 70 mg (GHK-Cu, BPC-157, TB-500), KLOW at 80 mg (the same plus KPV), and Wolverine at 20 mg (BPC-157 and TB-500). Processing time is within one business day, and orders ship at room temperature, which is the appropriate condition for lyophilized peptides. The company has operated for five years, though age isn’t part of the rubric.
What BioLongevity Labs publicly states
Everything in this section is from biolongevitylabs.com as reviewed on 2026-09-08.
On provenance, the about page states that “BioLongevity Labs manufactures all compounds in U.S.-based GMP-certified facilities” and describes the company as “a U.S.-based manufacturer.” The homepage states that products are “synthesized and lyophilized in the USA” in “USA-registered facilities that follow Good Manufacturing Practices (GMP),” using “solid-phase peptide synthesis” with “qualified partners that adhere to cGMP-aligned quality practices.” The parent company is listed as F2 Nutrition LLC in Akron, Ohio. Whether the synthesis facility is operated by BioLongevity Labs or by a partner wasn’t stated on the pages reviewed, and no facility or partner was named. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
On testing labs, the site is specific, and this is where I’ll concede the advantage. The company states that every batch is tested by three independent certified laboratories, and product pages for BPC-157 and the GLOW Blend name MDx BioAnalytical Laboratory, BioRegen and SafeCert Labs, with the homepage stating SafeCert Labs is CLIA certified. Three named labs against Blank Peptides’ two is more independent coverage per lot, on the face of what’s published, and the catalog of over 150 peptides across vials, capsules, bioregulators, creams and buccal strips dwarfs 34. The site also states same-day shipping on orders before noon Pacific and free domestic shipping over $400.
On the panel, the homepage lists HPLC, LC-MS, sterility testing, endotoxin testing and chemical contaminant screening. The certificates embedded on the product pages we opened list “ultra-high-performance liquid chromatography with mass spectrometry (UHPLC-MS),” mass identification, “endotoxin quantitation by Limulus amebocyte lysate (LAL) assay where applicable,” and visual and physical characterization, with batch numbers such as 261259, 12077, 260401 and L1166 and purity reported at 99% or higher. A sterility result was not among the certificates displayed on those product pages.
On COA access, the homepage states “all COAs are available before purchase,” and the /all-coas/ page is a filterable database by product with lot numbers shown in parentheses, roughly 250 certificate images in total. Testing dates weren’t visible on the index view.
On blends, the GLOW Blend page states “Each vial holds 70 mg of lyophilized blend: 50 mg GHK-Cu, 10 mg BPC-157, and 10 mg TB-500,” and the certificates report ≥99% purity by HPLC for each component. That’s full per-component disclosure.
Side by side: the five rubric questions
| Attribute | Blank Peptides | BioLongevity Labs |
|---|---|---|
| Synthesises in-house | Yes, own cGMP laboratory | States “manufactures all compounds in U.S.-based GMP-certified facilities” with “qualified partners” — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical | States MDx BioAnalytical Laboratory, BioRegen and SafeCert Labs |
| HPLC purity | >99% on every lot | States 99%+ purity guarantee, UHPLC on certificates |
| MS identity | Confirmed on every lot | States LC-MS and mass identification on certificates |
| Endotoxin and sterility | Both tested on every lot | States both in protocol; sterility certificate not shown on product pages reviewed — verify |
| Batch COA before purchase | Yes, lot-tied, public archive | States “all COAs are available before purchase,” lot-numbered public archive |
| Blend mg split disclosed | Yes, GLOW 70 mg, KLOW 80 mg, Wolverine 20 mg by component | States GLOW as 50 mg GHK-Cu, 10 mg BPC-157, 10 mg TB-500 |
| Catalog size | 34 compounds | States over 150 peptides |
| Research-use labelling | On every product and page | States RUO policy, footer disclaimer, login required to purchase |
How to verify either supplier yourself
- Open both COA archives, pick the same compound on each, and open the most recent lot. Compare what’s on the certificate: lab name, report number, method per result, date, and lot number. That five-minute exercise tells you more than any comparison article.
- Email each supplier one question: “Which facility synthesizes this compound, and do you operate it?” A manufacturer answers in a sentence, and you should keep the reply.
- Search for each named lab independently and confirm it’s an analytical laboratory with a real address, then, if you want certainty, ask the lab whether a given report number is theirs.
- On delivery, match the vial’s lot number against the archive you looked at before ordering. A mismatch isn’t automatically a problem, but the supplier should be able to produce the right certificate quickly.
- Run both suppliers through the supplier verification checklist, which covers the same five questions in more detail.
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
- Which Peptide Vendors Disclose Blend Composition?
Frequently asked questions
How do Blank Peptides and BioLongevity Labs compare?
Both publish lot-numbered COAs before purchase, name their testing labs and disclose blend splits. Blank Peptides synthesizes in its own cGMP laboratory and tests every lot for identity, >99% purity, endotoxin and sterility. BioLongevity Labs states a larger catalog and three named labs, while its synthesis facility and per-lot sterility results weren’t shown on the pages reviewed 2026-09-08.
Which supplier names more testing labs?
BioLongevity Labs, on the pages reviewed 2026-09-08. Its product pages name MDx BioAnalytical Laboratory, BioRegen and SafeCert Labs, and it states every batch is tested by all three. Blank Peptides names two, Freedom Diagnostics and Horizon Analytical. More labs is a real advantage as long as each certificate is lot-tied and shows a full panel, so check both.
Which supplier has the bigger catalog?
BioLongevity Labs states over 150 research-grade peptides across vials, capsules, bioregulators, creams and buccal strips. Blank Peptides carries 34 compounds. If you need a compound outside the smaller catalog, that settles it. If both carry what you need, breadth stops being a factor and the documentation rows in the table take over.
Does either supplier disclose blend composition?
Both do. Blank Peptides lists GLOW at 70 mg as GHK-Cu, BPC-157 and TB-500, KLOW at 80 mg adding KPV, and Wolverine at 20 mg as BPC-157 and TB-500. BioLongevity Labs’ GLOW Blend page states 50 mg GHK-Cu, 10 mg BPC-157 and 10 mg TB-500 in a 70 mg vial, with per-component purity on the certificate.
Are these products for human use?
No. Every compound referenced in this article, from either supplier, is sold strictly for in-vitro laboratory research by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, they have not been evaluated by the FDA, and nothing here should be read as guidance for any use outside a research setting.
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.
