You’ve got two tabs open, Blank Peptides in one and Power Peptides in the other, and both pages say roughly the same thing. Both mention third-party testing, both quote a purity number in the high nineties, both have a research-use-only banner at the bottom. So how do you pick one when the marketing copy reads like it came from the same template? That’s the situation I want to work through here, because the surface similarity hides some real differences in what each company lets you check.
I’ll say up front that we are Blank Peptides, which means this comparison comes from one of the two parties. The way I’ve tried to keep it fair is by holding both sites to the same five documentation questions, quoting Power Peptides in its own words, and pointing out where it does something better than we do. Where I couldn’t find something on their site, I say so with the date I looked, and I don’t assume it doesn’t exist somewhere behind a login or in a shipping box.
What you’ll get by the end is a table you can use to make the call yourself, plus a short list of things to check on either site before you order.
Key takeaways
- The useful comparison between two peptide vendors is about what each one documents in a form you can inspect, so the axis here is provenance, named lab, test panel, COA access, and blend disclosure.
- Blank Peptides compounds, vials, and QC-tests every lot in its own cGMP laboratory and has each lot tested by Freedom Diagnostics and Horizon Analytical for identity, >99% purity, bacterial endotoxin, and sterility.
- Power Peptides publicly states that it partners “with established manufacturing partners”, that batches are “independently tested by third-party US laboratories”, and that certificates are “available on our website for each product”.
- A laboratory name, a viewable lot-numbered certificate on the product pages I checked, and a sterility result were not listed on the pages reviewed 2026-09-08.
- All compounds discussed are for research use only, and nothing here is guidance on using any of them in people or animals.
What separates a documented supplier from an undocumented one?
Before naming anyone, let me lay out the five questions I’d ask of any vendor, because a head-to-head is only fair if both sides get the same questions.
Question one is provenance. Does the site say the company synthesizes the peptide, or does it describe sourcing, partnering, or supplying? The verbs matter. A company that runs its own synthesis can talk about the facility, the QC steps, and who signs off on release. A company that buys finished product can relay what its partner told it and not much else. Neither is disqualifying on its own, but it decides who is answerable when a lot fails.
Question two is whether the testing lab is named. A phrase like “third-party tested” carries no information you can act on until there’s a lab name attached. With a name you can look up the business, confirm it does peptide analysis, and even send your own sample for a comparison run.
Question three is the panel. HPLC purity tells you what fraction of the chromatogram is one peak. It doesn’t confirm the peak is the right molecule, which needs mass spectrometry, and it says nothing about bacterial endotoxin or sterility. If your work involves cells, those last two are where the surprises come from.
Question four is COA access. Can you open a certificate for a specific lot before you pay, and does that lot number appear on the vial when it arrives? A certificate you only see after purchase, or one with no lot tie, doesn’t help you choose.
Question five applies to blends. Is the milligram amount of each component stated, and is the product one co-formulated vial or a bundle of separate vials? Both are legitimate, but they’re different products, and the page should make it obvious which you’re buying.
I’m skipping company age and domain age, since neither tells you anything about the vial in your hand.
How Blank Peptides makes and tests each lot
Blank Peptides runs its own cGMP laboratory in the USA and handles compounding, vialing, finishing, labelling, and in-house QC for every product it sells. The company does not buy finished vials from another manufacturer, so the chain of custody from raw material to sealed box sits inside one facility, and that same facility also contract-manufactures and fulfils product for other peptide brands.
Each lot is released against a full panel rather than a single purity figure. Identity is confirmed, purity is reported at >99%, and the lot is tested for bacterial endotoxin and sterility. The outside testing is done by two named laboratories, Freedom Diagnostics and Horizon Analytical, which means a buyer can verify the lab and not only the number on the page.
Results for every lot are posted as batch certificates of analysis ahead of purchase, and the lot number printed on each vial matches the certificate on file. Lyophilized product carries an expiration of roughly 24 months.
The catalog runs to 34 compounds, and every blend states its composition per component: GLOW is 70mg made up of GHK-Cu, BPC-157, and TB-500; KLOW is 80mg and adds KPV to that trio; Wolverine is 20mg of BPC-157 and TB-500. Orders have a processing time within 1 business day and ship at room temperature, as is normal for lyophilized peptides. The company has been in business for five years.
What Power Peptides publicly states
Power Peptides sells at powerpeptides.com and lists a Florida address in its footer. On provenance, the homepage reviewed 2026-09-08 states that the company will “collaborate with established manufacturing partners to offer premium quality at affordable prices”, and the FAQ states, “Through strategic partnerships with established manufacturing partners, we provide premium-grade products while maintaining competitive pricing.” The About page describes the company as “your partner supporting research and scientific work”. A manufacturing partner’s name, a facility, or a country of synthesis was not listed on the pages reviewed 2026-09-08.
On testing, the About page states “Each batch is independently tested by third-party US laboratories to verify high standards” and shows a “Third Party Lab Verified” badge. The FAQ states that each product undergoes “comprehensive analytical characterization through both in-house and independent third-party laboratories, utilizing advanced techniques including NMR, FTIR, Polarimetry, HPLC, and LC-MS analysis.” The BPC-157, Epithalon, and GLOW Stack product pages list “HPLS Testing, Endotoxin Assay, TYMC Test, TAMC Test, Heavy Metal Screening” and carry a “Third party tested” badge. A laboratory name did not appear on any of those pages, and a sterility test, which is a different thing from the total microbial and yeast-and-mould counts listed, was not listed either.
On purity, the About page states “99% Purity Guaranteed” and “Our peptides meet or exceed minimum 99% purity levels”, while the FAQ states “Our single molecule product purity standard is ≥98% by HPLC and many of our products test ≥99%.” Those figures don’t quite agree with each other, which is a fair question to put to support.
On certificates, the homepage states “Certificates for each peptide’s testing results are available on our website”, the FAQ states “Complete certificates of analysis are readily accessible on our website for each product”, and the About page refers to “QR-Code Verified” access. The product pages I opened each list “Certificate of Analysis (COA)” in a table of contents, but a viewable certificate, a lot number, a lab name, or a purity value did not render on those pages, and the GLOW Stack page states a certificate accompanies each shipment. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
On blends, the GLOW Stack page does disclose the split: GHK-Cu 50mg, BPC-157 as two 5mg vials, and TB-500 10mg, packaged as four separate vials totalling 70mg. That is a clear disclosure, and it also makes plain that the “stack” is a bundle rather than a co-formulated blend.
Where Power Peptides has an honest advantage over us is shipping. Its policy states that orders “processed before 12pm CST Monday through Friday typically ship the same business day”, that “FedEx 2Day shipping is included on orders over $200.00”, that “Overnight shipping is included for orders over $500.00”, and that it accepts orders “from around the globe” apart from Canada and Spain. Its published method list, with NMR, FTIR, polarimetry, and heavy-metal screening, is also broader than a standard release panel, even if per-lot results weren’t shown where I looked.
Side by side: manufacturing, named labs, and the test panel
| Attribute | Blank Peptides | Power Peptides |
|---|---|---|
| Synthesises in-house | Yes, own cGMP laboratory | States “strategic partnerships with established manufacturing partners”; partner not named — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical | States “third-party US laboratories”; no lab named on pages reviewed 2026-09-08 — verify |
| HPLC purity | >99% on every lot | States “≥98% by HPLC” as standard and “99% Purity Guaranteed” elsewhere — verify |
| MS identity | Confirmed per lot | States “LC-MS analysis” as a method; per-lot result not shown — verify |
| Endotoxin and sterility | Tested per lot | States “Endotoxin Assay”, TYMC and TAMC; sterility not listed — verify |
| Batch COA before purchase | Public per lot at blankpeptides.com/coas/ | States certificates are “readily accessible on our website”; none rendered on product pages checked — verify |
| Blend mg split disclosed | Every blend, every component | States GLOW Stack as GHK-Cu 50mg, BPC-157 10mg, TB-500 10mg in separate vials |
| Catalog size | 34 compounds | Product count not stated on pages reviewed — verify |
| Research-use labelling | Research use only, on every product | States “not meant for human consumption of any kind” |
How to verify either supplier yourself
- Go to the product page for the compound you’d actually buy and look for a certificate there, not on a general quality page. Write down the lot number and, when the order arrives, compare it with the label on the vial.
- Read the method lines on any certificate you find. You want HPLC for purity, a separate mass spectrometry line for identity, and separate lines for bacterial endotoxin and sterility. Anything missing is a question for support, and the answer is worth keeping with your lab notes.
- If no lab is named on the site, ask for it by email. A working analytical laboratory has an address and a published scope of services; if the name you’re given turns up nothing, keep asking.
- For stacks or blends, confirm in writing whether you’re getting one co-formulated vial or several separate ones, and note the per-component milligrams before you order.
- Work through the supplier verification checklist for both vendors so you score them on the same five points rather than on whichever claim each site leads with.
Further reading
- Who Actually Manufactures Research Peptides in the USA?
- Which Peptide Vendors Name Their Testing Lab?
- 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 Power Peptides compare?
On the five documentation points, Blank Peptides names its two testing labs, publishes a per-lot certificate before purchase, and reports identity, >99% purity, endotoxin, and sterility. Power Peptides states third-party testing and certificates on its website, but a lab name and a viewable lot-numbered certificate were not listed on the pages reviewed 2026-09-08. Power Peptides states faster included shipping tiers.
Does Power Peptides manufacture its own peptides?
The site’s own language on the pages reviewed 2026-09-08 describes “strategic partnerships with established manufacturing partners” rather than an in-house synthesis facility, and a partner name or location was not listed. I’d read that as what it says and nothing more; if provenance matters to your work, ask support directly who synthesizes the material.
Which tests should a peptide COA include?
At minimum, HPLC purity with the percentage stated, mass spectrometry confirming the observed mass matches the expected sequence, a bacterial endotoxin result, and a sterility result. A lot number and a test date tie the document to your vial. Blank Peptides reports all four per lot; Power Peptides lists several of those methods but per-lot results were not shown where I looked.
Is a broader list of test methods better than a full release panel?
A longer method list isn’t better on its own. NMR, FTIR, polarimetry, and heavy-metal screening are real techniques and it’s good to see them listed, but a method list tells you what a company can do, while a per-lot certificate tells you what was done to your batch. Look for the certificate first, then treat extra methods as a bonus.
Are these products for human use?
No. Every compound mentioned, from either supplier, is sold strictly for in-vitro laboratory research. Power Peptides states its products are “not intended for human consumption, diagnostic, therapeutic, or other personal uses”, and Blank Peptides labels every vial research use only. Nothing on this page is guidance on dosing or administration 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.
