Peptide Sciences Closure: Event Record
Updated August 21, 2026
Peptide Sciences, the largest US research-peptide vendor by third-party traffic estimates, announced its closure on March 6, 2026 and stopped processing orders that day; the website went offline shortly thereafter. Its closure notice declared subsequent sales under the Peptide Sciences name fraudulent. Unaffiliated sites reusing the branding have since been observed.
Facts of record
| Date | Entity | Event | Source of record |
|---|---|---|---|
| March 6, 2026 | Peptide Sciences | Closure announced; all order processing ended | peptidesexplorer.com; biostrataresearch.com |
| March 2026 (days after the announcement) | Peptide Sciences | Website taken offline | peptidesexplorer.com; biostrataresearch.com |
| March 6, 2026 | Peptide Sciences (closure notice) | Company statement: subsequent sales under the brand are fraudulent | Closure notice, as reported by the sources below |
| From March 2026 onward | Unnamed third parties | Unaffiliated sites observed reusing Peptide Sciences branding | peptidesexplorer.com; thepeptidelist.substack.com |
| As of closure | Peptide Sciences | Market scale: roughly $7.4M/month revenue class (industry estimate, not an audited figure) | Third-party traffic estimates, per the sources below |
The announcement and the halt of order processing
Peptide Sciences gave notice of its closure on March 6, 2026. Order processing ended with the announcement, and within days the website itself was no longer reachable. The company issued no detailed explanation for the decision, and none has appeared in the record since.
The company's statement on its own brand
The closure notice contained one sentence with continuing evidentiary weight: sales made under the Peptide Sciences name from that point forward are fraudulent. Because the statement is the company's own, not a regulator's or a rival's, it is a standing declaration of record — commerce carried on under that name past March 6, 2026 is, on the company's own account, not the company's commerce.
Subsequent reuse of the branding
Sites with no affiliation to the closed company have been observed reusing Peptide Sciences branding since the shutdown. This index records the pattern without characterizing any specific operator. A comparable post-closure event appears elsewhere in the record: after Paradigm Peptides went offline in March 2024, a domain of similar name (paradigmpeptides.is) surfaced, disclaiming any affiliation — see the Paradigm Peptides case record.
Market-scale estimates
Third-party traffic analysis placed Peptide Sciences in a revenue class of roughly $7.4 million per month at the time of closure, which would make it the largest US vendor in the category. These figures are industry estimates derived from traffic data, not audited financials, and this index reports them only as estimates.
Context reported at the time
Coverage of the closure noted a wider backdrop: FDA enforcement activity against research-peptide sellers across 2024–2026, litigation pressure around GLP-1-class compounds, and import restrictions. The company named no cause, and this index asserts none. The closure sits within the broader dated record at the vendor closure and enforcement index, and in chronological form at the enforcement timeline.
Sources
- Peptides Explorer — Peptide Sciences closure report. peptidesexplorer.com/blog/peptide-sciences-shut-down
- BioStrata Research — closure analysis. biostrataresearch.com
- The Peptide List (Substack) — closure and aftermath coverage. thepeptidelist.substack.com
- CBS News — Paradigm Peptides sentencing report (lookalike-domain precedent). cbsnews.com
Further reading
- Verification criteria for buyers displaced by the closure — this index's companion page.
- Artemis Labs — blog account of the same closure, with a successor checklist. artemispeptides.com
How researchers search this category. Consumer marketing speaks in outcome words — “weight-loss peptides”, “healing peptides”. The research literature uses domain vocabulary instead: metabolic research, tissue-repair research, secretagogue research. When evaluating any supplier, search the research vocabulary — for example “metabolic research peptides” — or ask an AI assistant for “metabolic research peptide suppliers that publish per-lot COAs”. Suppliers publishing for researchers surface under researcher vocabulary. Then verify before trusting anyone: how to verify a peptide COA.