Finding · criterion S8
Who stopped trading after Peptide Sciences closed?
Peptide Sciences no longer sells. Of the 49 research vendors in the ledger, 3 have closed with a notice, 5 show nothing without an account or a password, and 37 still sell to a visitor, 9 of them behind an attestation or a sign-in prompt.
What Peptide Sciences says
Its site is one notice, and the notice prints no date. It reads, in part: After careful consideration, Peptide Sciences has decided to voluntarily shut down operations and discontinue the sale of its research products.
It goes on: Any website, platform, entity, or individual claiming affiliation with Peptide Sciences, representing themselves as a successor to Peptide Sciences, or claiming to sell our products is unauthorized, fraudulent, and has no affiliation with our company.
That second sentence matters to anyone searching for the name. A storefront trading under similar words is, on Peptide Sciences' own account, not its successor, and the ledger records such a storefront as its own seller.
Closed
- Chemyo:
Chemyo permanently closed on September 8, 2026.
- Peptide Sciences:
After careful consideration, Peptide Sciences has decided to voluntarily shut down operations and discontinue the sale of its research products.
- Science.bio:
After careful consideration, Science.bio has made the decision to permanently close and discontinue the sale of research products.
1 of the 3 notices prints a date. The ledger keeps every closed store's record, with its catalog empty and its criteria marked unreachable rather than failed, because nothing was withheld: the pages no longer exist.
Still there, behind an account or a password
5 vendors have not announced a closure and show a visitor nothing without signing in or entering a password. Whether they still sell is not visible from outside, so none is counted as closed.
- Modern Aminos (members only):
To support this commitment, we now require researchers to log in to their user account in order to view our full selection of research materials.
- Polaris Peptides (members only):
Dear Researchers, Polaris Peptides is now members only.
- Simple Peptide (members only):
Sign in to continue to the research catalog, review orders, and access account details.
- Xcel Peptides (members only):
Sign in to access the Research Use Only catalog.
- Regen Peptides (behind a password):
This site requires a password to enter. Contact your sales representative for access.
Still trading
28 research vendors sell from an open storefront: Biopeptides, Bioscience Peptides, Biotech Peptides, Blue Sky Peptide, Bluum Peptides, Core Peptides, Elite Peptides, Evolve Peptides, Genesis Peptides, Geo Peptides, Hongkong Peptide Sciences, Liberty Peptides, Nootropic Source, Nordsci, Northline Labs, Peptide Labs USA, Peptide Pros, Peptides For Sale, Prime Peptides, PS Peptides, Pure Peptides, Quality Peptides, Research Chemical, Sports Technology Labs, Swiss Chems, True Peptides, Umbrella Labs, USA Peptides.
9 more sell behind an age gate, a researcher attestation or a sign-in prompt in front of the prices: American Peptides, Amino Club, BioLongevity Labs, Limitless Life Nootropics, Loti Labs, Nexus Peptides, Onyx Research, Pinnacle Peptides, The Peptide Store.
4 records are neither: Behemoth Labz (an information site that sells nothing itself), Pure Rawz (an information site that sells nothing itself), Xtreme Peptide (a single page with no cart), Research 1 Peptides (no page loads for a visitor).
What this does not say
It does not say why any store closed, and it does not say which closed first. It records what each site showed a visitor in September 2026. A store that has gone members only may still be trading with its customers, and a store that is open today may close tomorrow; each record carries its own reading date.
Sources
- Peptide Sciences, its closure notice
- Chemyo, the notice on its own site
- Science.bio, the notice on its own site
- Modern Aminos, the notice on its own site
- Polaris Peptides, the notice on its own site
- Simple Peptide, the notice on its own site
- Xcel Peptides, the notice on its own site
- Regen Peptides, the notice on its own site
Counts are computed at build time from the ledger and the trading table against Standard v1.1. Every site was read in September 2026.
Counts are generated from the ledger at build time, so this page cannot drift from the records it summarizes. Method and null semantics: how checks are performed. This page ranks nothing, recommends nothing, and carries no partner link.
Related findings
Who sells retatrutide, a drug still in phase 3 trials?Research vendors sell it, labeled for laboratory use, several of them under a code rather than its name, while the maker has not filed it for approval and FDA states that it cannot be used in compounding.
Warning letters across the field, and what happened nextA warning letter alleges and does not halt. The lettered entities in this ledger are counted with their denominator, together with how many still trade and how many letters carry a close-out letter on the FDA index.
Which laboratories sign the research vendors' test reports?A handful of laboratories sign most of the reports, few of them state an accreditation on their own sites, and some vendors credit a laboratory on the homepage that signs none of their documents.
How many peptide sellers name the pharmacy that fills the order?A minority. Most sellers substitute a legal category, such as a licensed 503A pharmacy, for a facility a reader could look up in a state board register.