You can read both of these sites in twenty minutes and still not know which vial you would rather have, because they are careful about different things. One names the laboratories that run its analysis and publishes a long dated list of purity figures. The other describes the lot number stamped on the vial label resolving to a current, dated certificate on the product page, and says in writing that recycled certificates are unacceptable. Those are both real forms of discipline, and neither one substitutes for the other.
I write for a peptide manufacturer, and neither company below is that manufacturer, so nothing here tilts toward either of them. Five questions, put to both sites in identical wording, with the answers quoted from their own pages and every blank recorded as a gap in what has been published rather than as a claim about what happens off-page.
The observations come from sportstechnologylabs.com and cosmicpeptides.com as they stood on 2026-09-08. Product pages get rewritten and certificate arrangements change, so treat that date as part of every finding rather than as small print.
Key takeaways
- What separates two suppliers is who synthesized the lot, which laboratory tested it, how wide the panel ran, whether a certificate opens before payment and matches a lot number, and whether blends print per-component milligrams.
- Sports Technology Labs publicly names MZ Biolabs in Tucson, Arizona and Colmaric Analyticals, LLC, and keeps a certificate index with test dates running from January 2025.
- Cosmic Peptides publicly states that “every batch undergoes rigorous, independent third-party analysis using advanced High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS)” with a dated lot-specific certificate on each product page.
- Cosmic Peptides did not name a testing laboratory on the pages reviewed 2026-09-08, neither company named the party performing synthesis, and bacterial endotoxin was not listed by either.
- Everything referenced here is research material for in-vitro laboratory work by qualified professionals, and none of it is guidance for use in people or animals.
What should decide between two vendors making similar promises?
The rubric goes down before either name appears, otherwise this turns into a review of homepage copywriting.
Provenance leads. Does the company state that it synthesizes the material, or does it describe a synthesis method without saying whose hands are on it, or supplying material somebody else made? Verbs answer this where adjectives never will. Naming a technique tells you how the chemistry was done. Naming a facility tells you who is accountable for it, and those are separate pieces of information that often get printed as though they were one.
Second, is the laboratory named? Any site can print “independent US labs” and many do. A name with a city makes the claim checkable, since you can confirm the laboratory exists, read its accreditation scope, and ask whether a report number belongs to it. Without a name, the strength of the testing claim rests entirely on the vendor’s own word for it.
Third, how wide is the panel? HPLC purity reports what fraction of the material is a single species and nothing further. Mass spectrometry confirms that species is the sequence on the label. Bacterial endotoxin and sterility describe the finished vial rather than the powder, and they are distinct assays run by distinct methods, so a site claiming sterility without endotoxin has answered half of that pair.
Fourth, access and linkage. Can you open a batch certificate before paying, and does the lot number on that document appear on the vial when it arrives? A published purity figure with a date tells you what the company reports. A published document carrying a lot number that matches your label tells you what a laboratory measured on your material, and the difference between those is the difference between a summary and evidence.
Fifth, blend disclosure. A blend listed by name with no per-component split cannot be written into a methods section, so the split is what separates a citable product from a decorative one. Company age and domain age stay out of the list, since neither says anything about a lot.
Where this standard comes from
These five checks are the ones Blank Peptides publishes its own lots against, as batch certificates of analysis posted per lot. Neither company here is that one. Saying where a yardstick came from before applying it to two other businesses is the fair thing to do, since a measurement is worth something only if the party holding the ruler would accept being measured by it.
What Sports Technology Labs and Cosmic Peptides publicly state
Sports Technology Labs sells at sportstechnologylabs.com and ships its own inventory. On provenance, the homepage states products are “Bottled in the USA,” and the about page describes a supplier “proudly based in the United States” at a stated Shelton, Connecticut address, referring to “USP-Grade Solvents” and “Medical-Grade Glass.” The BPC-157 page states the peptide is “produced synthetically for laboratory use” and “packaged in America.” A statement that the company performs the synthesis itself, or naming the party that does, was not listed on the pages reviewed 2026-09-08.
Testing is its concession, and it is the row Cosmic Peptides leaves open. The about page states MZ Biolabs in Tucson, Arizona, described as a DEA-licensed facility, performs “HPLC purity analysis and molecular weight confirmation via Mass Spectrometry,” and it names Colmaric Analyticals, LLC for “ISO-accredited methodologies.” Naming two laboratories in prose and attaching each to a stated method is uncommon here, and it makes the claim checkable without the vendor’s help. Purity is stated as “our SARMs are minimum 98% pure, and our Peptides are minimum 96-99% pure,” with the BPC-157 page stating “Batch-tested to 99.43% (HPLC); minimum 98%.” The public certificate page lists product names, test dates and purity figures without an account, running January 2025 to June 2026 across roughly 18 peptide entries and 12 SARM entries, though lot numbers were not visible on that index. Bacterial endotoxin and sterility results were not listed on the pages reviewed 2026-09-08. Stacks ship as separate vials with stated amounts, the Glow Stack listing 5 mg BPC-157, 5 mg TB-500 and 50 mg GHK-Cu, and terms are stated as 68 listings, free US shipping over $149 and dispatch “within one business day.”
Cosmic Peptides sells at cosmicpeptides.com. On provenance, the homepage states products come from “Solid-phase peptide synthesis using pharmaceutical-grade reagents and the highest purity amino acids available” and refers to “advanced solid-phase peptide synthetic technology.” A statement that the company owns or operates the facility performing that synthesis was not listed on the pages reviewed 2026-09-08. On testing, the site states that “every batch undergoes rigorous, independent third-party analysis using advanced High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS),” with purity “guaranteed to exceed 99% purity,” and refers to “independent US labs” without naming one anywhere I could find. Its about page states “purity, sterility, and solvent testing are standard, not optional,” and bacterial endotoxin did not appear in the stated panel. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Its document hygiene is the concession, and it is a genuine one. The site states a “complete Certificate of Analysis with all analytical data posted directly on each product page,” and the about page states that “each vial carries a unique lot number printed directly on the label. That number links to its corresponding purity percentage, documented quantity (mg), and a current, dated COA,” adding that “outdated or recycled COAs are never acceptable.” Featured listings showed lot references in line with that, such as a MOTS-c entry marked “Lot: 26118.” Closing the loop between a printed label and a dated lot-specific document, then putting the rejection of recycled certificates in writing, is more than most companies in this market commit to. Blends at index level appear as “BPC-157/TB-500” and “GLOW (BPC-157, TB-500, GHK-Cu)” with no per-component milligram split shown, roughly 33 items were listed on the catalog page, shipping is stated as same-day dispatch before 2PM CST with free shipping over $200, and the site states products are “For Research Use Only” and “Not for Human or Veterinary Use.”
Side by side: named laboratories against lot-to-label linkage
| Attribute | Sports Technology Labs | Cosmic Peptides |
|---|---|---|
| Synthesises in-house | States products are “Bottled in the USA” and “packaged in America”; who synthesises not stated — verify | References “advanced solid-phase peptide synthetic technology”; no facility or ownership stated — verify |
| Third-party lab named | States MZ Biolabs (Tucson, AZ) and Colmaric Analyticals, LLC, with batch results attributed to MZ Biolabs — verify | States “independent US labs test everything”; no laboratory named — verify |
| HPLC purity | States peptides are “minimum 96-99% pure” and a batch figure of “99.43% (HPLC)” — verify | States purity “guaranteed to exceed 99%” by independent HPLC analysis — verify |
| MS identity | States “molecular weight confirmation via Mass Spectrometry” at MZ Biolabs — verify | States mass spectrometry identity verification on every batch — verify |
| Endotoxin and sterility | Not listed on pages reviewed 2026-09-08 — verify | States sterility and solvent testing as standard; endotoxin not listed — verify |
| Batch COA before purchase | States a public COA page with test dates and purity figures; lot numbers not visible on the index — verify | States a dated, lot-specific COA posted on each product page, tied to the lot printed on the label — verify |
| Blend mg split disclosed | States per-vial amounts for separate-vial stacks, such as 5 mg, 5 mg and 50 mg for Glow — verify | Lists blends as “BPC-157/TB-500” and “GLOW (BPC-157, TB-500, GHK-Cu)” without amounts at index level — verify |
| Catalog size | States 68 listings across liquid SARMs, SARM powders, peptides and stacks — verify | 33 items listed on the catalog page reviewed 2026-09-08, including two blends — verify |
| Research-use labelling | States products are “for research purposes only and are not for human consumption” — verify | States “For Research Use Only” and “Not for Human or Veterinary Use” — verify |
The two answer opposite halves of the certificate question. Sports Technology Labs tells you whose instrument produced the figure and then publishes the figure rather than the report. Cosmic Peptides publishes a dated report tied to the lot printed on your vial and declines to say who signed it.
How to verify either supplier yourself
- Work from the page for the exact compound and vial size you would order, not the homepage, and note the lot reference before you pay so you can hold it against the label when the box arrives.
- Where a laboratory is named, contact it directly and ask whether the report number belongs to it. Where no name appears anywhere on a site, ask support for it in writing before ordering, since a supplier confident in its testing rarely has a reason to withhold it.
- Read the method lines rather than the headline percentage, and ask both companies about bacterial endotoxin, which neither listed on the pages reviewed 2026-09-08.
- On blends, ask for the milligram split per component in writing where a listing shows only a blend name, because a combined figure alone cannot support a working concentration.
- Score both against the supplier verification checklist so the same rows get answered for each.
Further reading
- Which Peptide Vendors Name Their Testing Lab?
- Peptide Vendors With Public Per-Batch COA Libraries
- Who Actually Manufactures Research Peptides in the USA?
- Which Peptide Vendors Disclose Blend Composition?
Frequently asked questions
Sports Technology Labs vs Cosmic Peptides: which documents more?
They document different rows. Sports Technology Labs names MZ Biolabs and Colmaric Analyticals and publishes 18 months of dated purity figures. Cosmic Peptides states a dated, lot-specific certificate on each product page tied to the lot printed on the label, without naming the laboratory behind it on the pages reviewed 2026-09-08.
Does Cosmic Peptides name its testing laboratory?
Not on the pages reviewed 2026-09-08. The site refers to “independent US labs” and states that every batch undergoes independent third-party HPLC and mass spectrometry analysis, without giving a laboratory name anywhere I could find. Asking support for that name before ordering is a reasonable step.
Which one ties a certificate to the vial you receive?
Cosmic Peptides states it does, describing a unique lot number printed on each label that links to a current, dated COA, and stating that recycled certificates are never acceptable. The Sports Technology Labs certificate index showed product names, test dates and purity figures without visible lot numbers on the pages reviewed 2026-09-08.
Does either publish endotoxin results?
Neither did on the pages reviewed 2026-09-08. Cosmic Peptides states sterility and solvent testing as standard without an endotoxin line, and Sports Technology Labs listed neither endotoxin nor sterility. That limits what was readable rather than describing what testing was performed, so request the result for your lot in writing.
Are these products for human use?
No. Everything referenced here is research material intended for in-vitro laboratory work by qualified professionals. Purity percentages, laboratory names and certificate pages describe documentation and nothing else. Nothing in this article is dosing guidance, medical advice, or a recommendation to use any compound outside a controlled laboratory 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.
