On March 6, 2026, Peptide Sciences replaced its homepage with a three-sentence notice saying it had voluntarily decided to shut down and discontinue sales of its research products. The site went dark the same day.
There was no advance warning and no guidance for anyone holding an order in transit. For years the company had been the default answer to “where do I buy.” By that evening it was a parked domain.
If you found this page you are looking for somewhere else to order from. So here is a straight comparison between what Peptide Sciences offered and what we do, on the parts that are actually checkable. Everything we sell is supplied for laboratory research use only.
What happened
Peptide Sciences called the closure voluntary and gave no further explanation. No public FDA warning letter to the company appears in the agency's warning letter database, which is public and searchable if you want to check that yourself. The closure did come during a stretch of heavier federal enforcement across this market, though the actions reported in that period involved other companies.
Sites using their name are not them
What Peptide Sciences got right
They carried a genuinely deep catalog, which meant a researcher working across several compound classes could source everything from one place. They shipped internationally, which we do not. They had been operating long enough to build real name recognition, and they published certificates of analysis at a time when plenty of vendors published nothing at all.
If your work needs a compound outside a short catalog, they were the better supplier and we are not a replacement for them. That is the honest version, and no amount of testing depth on our side changes it.
What went offline with them
When peptidesciences.com went down, the COA library went with it.
If you have a vial from them sitting in a freezer right now, the certificate for that lot is not retrievable. Neither is the order record, the terms page, or the support inbox. The documentation lived on their servers, which means it existed at their discretion and only for as long as they did.
A certificate you cannot independently confirm is a certificate you are renting from the vendor.
That is the part worth carrying into wherever you order next. The question is not whether a vendor shows you a PDF. It is whether anyone other than that vendor can confirm the PDF is real.
How we compare
On the axes buyers actually cared about with Peptide Sciences:
| Criterion | Peptide Sciences | Validated Peptides |
|---|---|---|
| Status | Closed March 6, 2026 | Operating |
| Batch testing | Certificates published per compound | Seven-point panel on every batch |
| Who holds the record | Vendor-hosted PDFs, now offline | Outside laboratory, confirmable directly with them |
| Catalog | Broad, spanning most compound classes | Narrow |
| Shipping reach | US and international | US only |
| Dispatch and delivery | Terms offline since closure | Same-day dispatch before the daily cutoff, 2 to 3 business days by 2nd Day Air |
| Damage guarantee | Terms offline since closure | Photo within 72 hours and we ship a replacement, no return required |
| Returns | Policy no longer reachable | 30 days from delivery for a refund or replacement |
| Track record | Years of operating history | Substantially shorter |
What seven-point testing covers
Most research peptide certificates report one number: purity by HPLC. That number is useful, and it is also the easiest test to pass. A vial can be 99% pure and still be the wrong molecule, still be mostly salt by weight, or still carry enough bacterial residue to ruin a cell-based assay.
A seven-point panel answers the questions a purity figure leaves open. Ours covers:
- Purity by HPLC, against a release threshold of 99%
- Identity, confirming the molecule matches the label
- Net peptide content, which is how much of the powder weight is actually peptide rather than water and salts
- Heavy metals by ICP-MS
- Sterility
- Endotoxin, which is a different question from sterility
- Fentanyl screen
Sterility and endotoxin sit on separate lines for a reason. A batch can be completely sterile and still carry enough endotoxin to skew an assay, so a vendor can run one, skip the other, and still describe the material as tested.
Confirm it with the lab, not with us
Shipping and damaged deliveries
Orders placed before the daily cutoff leave the same day. 2nd Day Air puts most domestic orders in hand in two to three business days, and Ground runs three to five and is free over $200. Everything moves tracked.
What matters more is what happens when a package goes wrong in transit. Send a photo within 72 hours of delivery and we ship a replacement. We do not ask for the damaged vial back, and we do not ask you to cover return postage on a package you did not break.
Both policies are published on the site, so you can read the terms before you order instead of finding out what they are after something breaks.
Where we do not match them
Peptide Sciences had a deep catalog and years of name recognition. We have neither, and claiming otherwise would undercut the entire point of this page.
Our catalog is narrow, and narrow means some compounds are not on it. We ship inside the United States only. We have been doing this for a fraction of the time they had.
Ask which lot you are getting, then read the report for that lot and confirm it with the lab that issued it. That process works on any supplier, including the ones this article does not name.