You’ve got a compound to source and two US suppliers that both look credible. One says its peptides are synthesised domestically by its own team. The other says its material is bottled in America and names the laboratory that tested it. Those are different claims about different parts of the same process, and the storefronts present them with equal confidence, which makes the choice harder rather than easier.
This piece is written by a peptide manufacturer that isn’t either of these companies, which is the point of it, because no order rides on the outcome. What follows is the reading I’d do for my own sourcing: open both sites, note who claims to make the material, who tests it, what tests were run, and what document a buyer can open before paying. Where a page says nothing, I record the silence rather than treating it as evidence. Everything comes from pages reviewed 2026-09-08.
Key takeaways
- The comparison that holds up is documentation before purchase: provenance, named labs, panel scope, certificate timing, and blend disclosure.
- Biotech Peptides states its peptides are domestically synthesised by its own US-based team, verified by HPLC-MS to >99% purity, with dated lot-numbered certificates linked on product pages.
- Sports Technology Labs states its products are “Bottled in the USA,” names MZ Biolabs in Tucson and Colmaric Analyticals as its testing partners, and maintains a public COA page with test dates and purity figures.
- Neither site listed a bacterial endotoxin or sterility result on the pages reviewed 2026-09-08, and the two answer the provenance question at different points in the chain.
- Everything referenced here is research-use-only material for in-vitro laboratory work by qualified professionals, and none of it is dosing or clinical guidance.
Which five questions separate two peptide suppliers?
Set the criteria before either name appears, because a rubric written after browsing will quietly reward whichever site you found more convincing. Five questions, all answerable from published material.
Provenance first. Does the company synthesise the peptide itself, or does it finish, bottle and label material made elsewhere? Both are real businesses, and the second is not a criticism, but they answer differently when a lot turns out to be wrong. A manufacturer traces the problem through its own records. A finisher relays what the upstream producer says. The verbs on the about page settle this faster than any amount of marketing prose.
Second, is the testing laboratory named? “Third-party tested” is a phrase with nowhere to go. A named laboratory is an organisation you can look up, whose accreditation you can confirm and whose report format you can compare against the file on the product page. This row is binary, and plenty of vendors fail it.
Third, panel scope. HPLC purity tells you what fraction of the material is a single compound. Mass spectrometry identity tells you that compound is the one on the label. Bacterial endotoxin and sterility tell you what else is present, which purity never will. Four results and two results are different levels of assurance even when the purity figure is identical.
Fourth, timing and traceability. Can you open a batch certificate before paying, and does the batch number on it appear on the vial that arrives? A public results page listing purity percentages by date is useful, and it becomes far more useful once a batch identifier ties a row to a vial.
Fifth, blends. When peptides are sold together, are the milligrams of each stated? That applies whether they share a vial or ship as a set, and the answer belongs on the product page rather than in an email.
Company age and domain age stay off the list, since neither describes the material.
Where this standard comes from
These five questions are the standard Blank Peptides publishes its own lots against, as batch certificates of analysis posted per lot. It’s worth naming the source before turning the same rows on two other companies, because a rubric holds up only if the person holding it would accept the same measurement.
What Biotech Peptides and Sports Technology Labs publicly state
Take Biotech Peptides first. On provenance, the homepage states that “peptides are domestically synthesized, backed by our knowledgeable US-based team,” the about page states that its team “specializes in the precise synthesis and lyophilization of these delicate structures,” and product pages carry “Synthesized and Lyophilized in the USA.” No facility, city or state was named on the pages reviewed 2026-09-08.
On testing, the homepage states that “our production is verified by HPLC-MS to confirm >99% purity” and that “every batch is verified by a third-party lab, with results posted on our website.” No laboratory is named in that prose, though the certificate linked from the 70mg BPC-157, TB-500 and GHK-Cu blend page, lot 3141011, is issued by MZ Biolabs and reports HPLC-UV purity of 99.56% with mass spectrometry identity confirmation. Endotoxin and sterility were not listed on that certificate or on any page reviewed 2026-09-08. Certificate files are linked on product pages before purchase, including separate documents for the 5mg and 10mg BPC-157 vials dated 2026-07-21, and the 70mg blend page states a total without per-component milligrams. The shop reads “Showing 1–28 of 89 results,” split as 73 peptides and 16 blends, and shipping states a 1pm PST same-day cutoff with no returns and free replacement of lost or damaged parcels.
Sports Technology Labs answers the provenance question at a later point in the chain. The homepage states products are “Bottled in the USA,” the about page describes the company as a supplier “proudly based in the United States” with a Connecticut address, and refers to “USP-Grade Solvents” and “Medical-Grade Glass.” The BPC-157 product page states the peptide is “produced synthetically for laboratory use” and “packaged in America.” A statement that Sports Technology Labs synthesises the peptides itself, or naming who does, was not listed on the pages reviewed 2026-09-08.
On the laboratory row, Sports Technology Labs does something most vendors don’t. The about page names MZ Biolabs in Tucson, Arizona, describes it as a DEA-licensed facility, and states that it performs “HPLC purity analysis and molecular weight confirmation via Mass Spectrometry.” It also names Colmaric Analyticals, LLC for “ISO-accredited methodologies.” Product pages attribute batch results to MZ Biolabs by name. That’s worth pausing on, because the certificate Biotech Peptides links is issued by that same laboratory. Both suppliers used MZ Biolabs, and what separates them on this row is whether the site tells you so before you open a PDF.
On panel scope, the about page states “our SARMs are minimum 98% pure, and our Peptides are minimum 96-99% pure,” and the BPC-157 page states “Batch-tested to 99.43% (HPLC); minimum 98%.” Bacterial endotoxin and sterility results were not listed on the pages reviewed 2026-09-08. The site maintains a public COA page showing product names, test dates and purity percentages, viewable without a purchase, with dates from January 2025 to June 2026 and roughly eighteen peptide entries alongside the SARMs. Lot or batch numbers were not visible on that page as reviewed, though product pages refer to a “Most recent batch certificate of analysis” and describe certificates as batch-linked. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed. Blends ship as separate vials: the Glow Stack page states 5mg BPC-157, 5mg TB-500 and 50mg GHK-Cu, each in its own vial with its own HPLC figure, and the Wolverine Stack states 5mg of each peptide.
Both earn a concession. Biotech Peptides ties its certificate to a lot number on the product page, publishes a larger peptide catalogue at 89 listings, and sells its blends as single vials, which some protocols prefer. Sports Technology Labs names two laboratories in its own copy rather than leaving a buyer to find the name on a PDF, states 68 listings across liquid SARMs, powders, peptides and stacks, offers free US shipping over $149, ships within one business day, and accepts a 60-day exchange on unused items, which is a longer window than most of this market offers.
Side by side: provenance, named labs and panel scope
| Attribute | Biotech Peptides | Sports Technology Labs |
|---|---|---|
| Synthesises in-house | States peptides are “domestically synthesized” by its own US-based team; facility not named — verify | States “Bottled in the USA” and “packaged in America”; synthesis source not listed — verify |
| Third-party lab named | Not named in site prose; MZ Biolabs appears on a linked COA — verify | States MZ Biolabs (Tucson, AZ) and Colmaric Analyticals, LLC by name |
| HPLC purity | States HPLC-MS confirms >99%; 99.56% on the blend COA examined | States peptides “minimum 96-99% pure”; BPC-157 batch-tested to 99.43% |
| MS identity | States mass spectrometry confirms molecular weight; shown on the COA examined | States “molecular weight confirmation via Mass Spectrometry” at MZ Biolabs |
| Endotoxin and sterility | Not listed on pages or certificates reviewed 2026-09-08 — verify | Not listed on pages reviewed 2026-09-08 — verify |
| Batch COA before purchase | States results are posted; lot-numbered COA files linked on product pages | States a public COA page with product names, dates and purity; lot numbers not visible — verify |
| Blend mg split disclosed | States a 70mg total for its three-peptide blend; per-component mg not listed — verify | States per-vial mg for stacks sold as separate vials |
| Catalog size | States 89 products, 73 peptides and 16 blends | States 68 listings including SARMs, powders, peptides and stacks |
| Research-use labelling | States “research, laboratory, or analytical purposes only” | States products are “for research purposes only and are not for human consumption” |
Reading down the columns, the two hold opposite halves of the same set. Biotech Peptides states manufacture and attaches a lot number to its certificate while saying nothing in prose about which lab ran the test. Sports Technology Labs names the laboratory in plain sight and publishes a dated results page, while describing its role as bottling and packaging and showing no batch identifier on that page. Neither published endotoxin or sterility, which for cell-based work is the shared gap I’d raise with both.
How to verify either supplier yourself
- Ask each company in writing who synthesises the peptide and where, then ask for the batch report for the specific lot they’d ship you. Two questions, one email, and the answers separate suppliers quickly.
- Open a certificate before ordering and read the header rather than the purity figure. You want the issuing lab, the batch number, the date, and a line for each method run.
- Count the results: identity by MS, purity by HPLC, bacterial endotoxin, sterility. Fewer than four means the panel is partial regardless of the site copy.
- Match the number on the document to the number printed on the vial when it arrives, and keep both together with your lab records.
- Put both suppliers through the supplier verification checklist and repeat the exercise whenever either site changes.
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
How do Biotech Peptides vs Sports Technology Labs compare on testing?
Both state HPLC purity and mass spectrometry identity, and neither listed bacterial endotoxin or sterility on the pages reviewed 2026-09-08. Sports Technology Labs names MZ Biolabs and Colmaric Analyticals in its own copy, while Biotech Peptides states third-party verification without naming a lab, though MZ Biolabs appears on the certificate it links.
Which one says it synthesises its own peptides?
Biotech Peptides states that its “US-based team specializes in the precise synthesis and lyophilization” of peptides and labels products “Synthesized and Lyophilized in the USA.” Sports Technology Labs states products are “Bottled in the USA” and “packaged in America,” which describes finishing rather than synthesis.
Can you see certificates before buying from either?
Yes, in different formats. Biotech Peptides links lot-numbered certificate files on product pages, including separate files for the 5mg and 10mg BPC-157 vials dated 2026-07-21. Sports Technology Labs publishes a public COA page listing products, test dates and purity figures, without visible lot numbers.
How do the two handle blends?
Biotech Peptides lists 16 blends as combined vials and states a total, such as 70mg for BPC-157, TB-500 and GHK-Cu, without per-component milligrams. Sports Technology Labs sells stacks as separate vials and states the mass of each, for example 5mg BPC-157, 5mg TB-500 and 50mg GHK-Cu.
Are these products for human use?
No. Every compound referenced here is intended for in-vitro laboratory research by qualified professionals. Biotech Peptides states products are sold “for research, laboratory, or analytical purposes only, and are not for human consumption,” and Sports Technology Labs states its products are “for research purposes only and are not for human consumption.”
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.
