You’re trying to pick an Epithalon supplier and the pages have all blurred together. Every one of them says 99% purity. Every one says third-party tested. The vial sizes jump around, 10mg here, 20mg there, 25mg somewhere else, and the prices don’t line up with the milligrams in any pattern you can follow. After a while the honest position is that you can’t tell these vendors apart from their websites, which is uncomfortable when you’re about to hand one of them a card number.
Epithalon has a quirk that makes the 99% claim less useful than it looks. It’s a tetrapeptide, Ala-Glu-Asp-Gly, molecular weight around 390. Four residues is about as short as synthesis gets, and short chains assemble cleanly, so a high chromatographic purity is the expected result rather than a sign of unusual skill. What’s harder, and what separates one vendor from another, is whether anyone confirmed the identity by mass spectrometry, whether the vial was checked for contamination, and whether the milligrams on the label are peptide or peptide plus counterion and residual water. At 390 daltons a trifluoroacetate counterion is a meaningful fraction of the mass, which is exactly the sort of thing a certificate can settle and a product page usually doesn’t.
So this article compares four named Epithalon vendors on what they publish rather than on what they charge. Everything below describes what was visible on the pages reviewed 2026-09-08, and I’ve kept “not listed” separate from any claim about what a company holds internally. Only the first of those is something I can honestly report.
Key takeaways
- The comparison worth making between Epithalon vendors is documentary, meaning who names the laboratory, who publishes a batch-linked certificate readable before payment, and who reports identity and contamination rather than purity alone.
- Blank Peptides synthesizes, vials and releases Epithalon in its own cGMP laboratory, with each lot tested for identity, >99% purity, bacterial endotoxin and sterility by Freedom Diagnostics and Horizon Analytical.
- Sports Technology Labs, Protide Health, BioLongevity Labs and Biotech Peptides all publish Epithalon documentation, and the stated purity figures range from a measured 95.32% to a round 99%.
- Sterility results were absent from all four stated panels on the pages reviewed 2026-09-08, and one page named no issuing laboratory anywhere.
- Epithalon from every vendor named here is supplied for in-vitro laboratory research by qualified professionals, and nothing in this article describes or implies any other use.
What should an Epithalon product page prove before you order?
Let me put the standard down before naming anyone, so you can disagree with the standard rather than with my reading of a page. Five questions, and they hold for any research compound sold this way.
Provenance comes first. Does the vendor state that it made the material, or does its language describe supplying material produced somewhere else? Read the verbs on the about page rather than the adjectives on the product page. A company that owns the synthesis owns the certificate describing it, while a company that buys finished vials is passing along a document from a source it may never name.
Second, the laboratory. Whoever ran the analysis should be named on the certificate in a form you can look up and telephone. A report credited to “an independent third-party lab” is a claim about a document, and no one at that description will confirm a report number when you call.
Third, the panel. HPLC reports the share of the sample eluting as the target peak. Mass spectrometry confirms that peak is Epithalon and not a truncated sequence, which matters even at four residues because a missing glycine changes the mass by enough to spot and not always enough to shift retention time far. Bacterial endotoxin and sterility catch contamination neither chromatographic method sees, and in cell culture that contamination reads as an effect in your data.
Fourth, access and batch linkage. Open the certificate before you pay, and match its batch number against the vial label when the package arrives. A report supplied only on request afterwards verifies nothing in advance.
Fifth, for blends, whether the milligram amount of each component is disclosed, since a purity figure on a combined vial can’t tell you the ratio inside it.
Those five apply to us too. Everything below is the five questions run against four sites.
How Blank Peptides makes and tests each lot
Blank Peptides operates its own cGMP laboratory in the United States, where it compounds, vials, finishes and labels product and performs quality control release in-house. The company describes this as holding the full chain of custody rather than relabeling or brokering material made elsewhere, and it separately contract-manufactures and fulfils for other research peptide brands as a distinct business line.
Every lot is released against a four-part panel: identity, purity at a >99% threshold, bacterial endotoxin, and sterility. The analytical work is carried out by two named independent laboratories, Freedom Diagnostics and Horizon Analytical. Reports are published per lot as batch certificates of analysis, which can be opened before an order is placed, and each vial carries the lot number that ties it back to its report. Lyophilized material is dated for roughly 24 months from release.
The catalog runs to 34 compounds, Epithalon among them, and includes three blends whose composition is itemised per component rather than sold as one combined weight: GLOW at 70mg (GHK-Cu, BPC-157, TB-500), KLOW at 80mg (those three plus KPV), and Wolverine at 20mg (BPC-157 and TB-500). Processing time is within 1 business day, and orders ship at room temperature, which suits lyophilized peptide without cold-chain handling. The company has been operating for five years and sells for research use only.
That standard is narrow by design. It covers who made the vial, who tested it, what was tested and where the report lives, and it stays silent on price and catalog breadth.
What four Epithalon vendors publicly state
On the pages reviewed 2026-09-08, Sports Technology Labs listed a 10mg Epitalon vial at $51.99 and states the batch was “batch-tested to 95.32% (HPLC)” with third-party verification by MZ Biolabs of Tucson, Arizona, using HPLC and mass spectrometry. The site states that “published certificates of analysis are published on our website” with “no login required” and that certificates are batch-linked. The vial is described as lyophilized in sterile UV-resistant glass, “lyophilized and packaged in America”, labelled “research use only” and “not for human or animal consumption”, with refrigeration described as applying after reconstitution.
Protide Health listed Epithalon 10mg at $75.00 in a 3ml vial, stating “99% Purity (HPLC-MS Verified)” and “Independent Third-Party Tested” by Freedom Diagnostics. The page gives the sequence Ala-Glu-Asp-Gly and formula C14H22N4O9, states its methods as identity by LC-MS, purity by HPLC-UV and endotoxin by LAL assay under USP <85>, and links two batch certificates readable before purchase: 99.80% purity under COA 2605280422 dated May 2026, and 99.862% under COA 2510010072 dated October 2025.
BioLongevity Labs listed Epithalon 20mg at $47.49, reduced from $94.97, stating “≥99% (HPLC)” purity with a certificate of analysis included per batch and independent testing through MDx BioAnalytical Laboratory, BioRegen and SafeCert Labs. The page gives the AEDG sequence, molecular weight 390.35 and CAS 307297-39-8, and states “GMP manufacturing standards”, synthesis “in USA-registered facilities” and “zero fillers or additives”.
Biotech Peptides listed Epithalon 25mg at $94.00 with bulk pricing down to $84.60, stating “99% purity” and displaying certificate documentation covering LC and MS testing dated April 2026. The page states the material is “synthesized and lyophilized in the USA”. No issuing laboratory was named in the visible page content.
A sterility result appeared in none of the four stated panels, and a measured net peptide content appeared in none of them either. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Credit where it belongs: Sports Technology Labs publishes a measured 95.32% rather than rounding up to the category’s standard 99%, names the testing laboratory and its city, and keeps its certificate library open without a login. That combination is more candid than most Epithalon pages manage, and it’s the sort of number a vendor only publishes if it publishes what it measures.
Side by side: Epithalon documentation
| Attribute | Blank Peptides | Typical Epithalon vendor |
|---|---|---|
| Synthesises in-house | Own cGMP lab; synthesis through QC release under one roof | Commonly states “synthesized and lyophilized in the USA” or “USA-registered facilities”, without stating who owns the synthesis — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical | Named by three of four vendors reviewed 2026-09-08, one naming three labs; absent from the fourth page — verify |
| HPLC purity | >99% per lot | States figures from a measured 95.32% to a stated 99% or ≥99% across the pages reviewed — verify against the linked document |
| MS identity | Confirmed per lot | States mass spectrometry or LC-MS on three of four pages reviewed 2026-09-08 — verify |
| Endotoxin and sterility | Both tested per lot | States endotoxin on one page; sterility was not listed in any of the four panels reviewed 2026-09-08 — verify |
| Batch COA before purchase | Public library at /coas/, lot-numbered, every lot | States batch-linked certificates readable without an account on two pages, per-product documents on the others — verify |
| Blend mg split disclosed | GLOW, KLOW and Wolverine itemised per component | Epithalon is generally sold as a single compound; where combined, per-component splits were not listed on the pages reviewed — verify |
| Catalog size | 34 compounds | States catalogs from tens to over a hundred listings, with Epithalon offered at 10mg, 20mg and 25mg |
| Research-use labelling | Research use only, stated on every product | States research-use-only language on all four sites reviewed |
How to verify either supplier yourself
- Open the Epithalon certificate before anything goes in your cart, and read the issuing laboratory, batch number and report date off the document rather than from the copy above it.
- Ask the named laboratory to confirm the report number exists. A working contract lab will answer that, and a page naming no lab gives you nobody to ask.
- Ask whether the milligrams on the label are net peptide content or gross weight, because at a molecular weight around 390 the counterion and residual water make up a larger share of the vial than they would for a longer peptide.
- Count the result lines: HPLC purity, mass spectrometry identity, bacterial endotoxin, sterility. Every absent line is a test you’ll run yourself or a risk you’re accepting without saying so.
- Take any vendor you’re weighing through the supplier verification checklist before a first order.
Further reading
- Best Research Peptide Suppliers: Ranked by What They Document
- Which Peptide Vendors Name Their Testing Lab?
- Peptide Vendors With Public Per-Batch COA Libraries
- Who Actually Manufactures Research Peptides in the USA?
Frequently asked questions
Who are the best Epithalon vendors?
Judged on public documentation rather than price, the strongest Epithalon pages reviewed 2026-09-08 were those publishing batch-linked certificates from a named laboratory. Sports Technology Labs named MZ Biolabs and published a measured 95.32%, Protide Health named Freedom Diagnostics and dated two batches, and BioLongevity Labs named three laboratories. Blank Peptides publishes identity, >99% purity, endotoxin and sterility per lot.
Does a 99% purity claim mean much for a tetrapeptide?
Less than it does for a long chain. Epithalon is four residues at roughly 390 daltons, and short sequences assemble cleanly, so high chromatographic purity is the ordinary outcome. The figure becomes informative once it’s tied to a dated certificate from a named laboratory with a batch number you can match to your vial.
Why does mass spectrometry matter for Epithalon?
Chromatography reports how much of the sample elutes as one peak without establishing which molecule that peak is. A truncated sequence missing a residue can sit close enough in retention time to pass unnoticed. Mass spectrometry confirms the molecular weight matches the AEDG tetrapeptide, which resolves the question chromatography leaves open.
Should I ask about net peptide content?
Yes, particularly here. Synthetic peptides are commonly isolated as salts, and at a molecular weight around 390 the counterion and residual moisture make up a larger proportion of the vial than they would for a larger peptide. A certificate reporting net peptide content tells you how much Epithalon the 10mg label represents.
Are these products for human use?
No. Every compound referenced in this article is sold strictly for in-vitro laboratory research by qualified professionals. Blank Peptides sells for research use only, and each vendor reviewed publishes research-use-only language of its own, including Sports Technology Labs’ statement that its product is “not for human or animal consumption”. Nothing here should be read as guidance for any use outside a 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.
