The 2025-2026 Peptide Vendor Closure Wave, Explained

Between March 2024 and March 2026, at least four major US research-peptide vendors closed for four very different reasons: a criminal conviction, a federal raid, a voluntary pre-emptive exit, and the abrupt shutdown of the largest name in the category. Taken individually, each is a single company's story. Taken together, they describe a market where the operating assumptions of the last decade no longer hold. This post lays out each closure with its own facts, then looks at what they share.

Paradigm Peptides — the earliest domino, and a criminal case

Paradigm Peptides shut down in March 2024 amid a federal investigation. The business, operated by Matthew Kawa through 'Paradigm R.E. LLC' out of Michigan City, Indiana, with his sister Jennifer Stechkober as an employee, sold SARMs, hCG, and peptides. Prosecutors alleged the company sold these as unapproved new drugs, falsely claimed FDA licensing and US-lab manufacturing and testing, and continued selling despite receiving FDA warning letters in 2020 and 2022. Investigators say products were actually imported without testing from China, India, and elsewhere, while the company marketed itself as 'made in America' with 99% purity and third-party lab testing.

From 2019 to 2024, the business reportedly sold to more than 54,000 customers across all 50 states and 80-plus countries, generating $5 million in proceeds. Some customers who used products mislabeled as SARMs but that actually contained testosterone reported serious health effects. On December 10, 2025, Kawa and Stechkober pleaded guilty in United States v. Matthew Kawa (N.D. Indiana). Kawa was sentenced to nearly six years — 70 months — in prison; Stechkober received 16 months.

Amino Asylum — from warning letters to a physical raid

Around June 18, 2025, federal authorities — the FDA, coordinated with the DOJ — physically raided Amino Asylum's Texas warehouse. Payment processing was cut and the website taken down immediately, with no wind-down process established for customers or pending orders; the site has stayed dark since. Amino Asylum had reportedly been among the top five most-searched peptide vendors in the US prior to the raid, with 400,000-plus monthly site visitors, known for aggressive pricing and a very wide catalog spanning peptides, SARMs, and nootropics.

Reported causes included ignoring prior FDA warning letters (the FDA had already sent letters to multiple vendors — Prime Peptides, Xcel Peptides, SwissChems, and Summit Research — in December 2024), marketing products for human consumption, selling prescription-only medications alongside peptides and SARMs, and using trademarked pharmaceutical brand names in marketing. In December 2025, founders Matthew Kawa and Jennifer Stechkober pleaded guilty to federal charges tied to SARMs products that were found to actually contain testosterone, a controlled substance — the same defendants and case later tied to Kawa's earlier venture, Paradigm Peptides.

Paradigm Peptides and Amino Asylum share a founder — Matthew Kawa — and the same underlying criminal case, per DOJ filings. A vendor's marketing identity and its legal identity aren't always the same thing.

Science.bio — an exit ahead of enforcement

Science.bio, a well-regarded US supplier of research compounds, nootropics, and peptides, announced a voluntary, permanent closure on January 27, 2026, with no advance warning: 'After careful consideration, Science.bio has made the decision to permanently close and discontinue the sale of research products.' Unlike Amino Asylum or Paradigm Peptides, Science.bio was not raided or criminally charged — the company chose to exit ahead of enforcement, and committed to fulfilling or fully refunding all outstanding orders.

The company attributed the closure to a convergence of pressures: 50-plus FDA warning letters industry-wide by September 2025, physical raids on competitors, criminal prosecutions, payment processors increasingly restricting research-compound sales, ITC-driven import blocks on tirzepatide, and the proposed SAFE Drugs Act. Science.bio warned that any site claiming to be a successor is fraudulent, with no relaunch planned.

Peptide Sciences — the largest name closes last

Peptide Sciences, long considered the largest US research-peptide vendor by revenue, voluntarily shut down on March 6, 2026, with the same abruptness as Science.bio: a brief on-site statement, no detail on outstanding orders, and the same pattern of preceding federal pressure — including the HHS move to shift roughly 14 of 19 restricted peptides back to Category 1 status. Any site currently using the Peptide Sciences name or branding is confirmed fraudulent. We cover this closure in more detail in a dedicated timeline post.

Why vendor due diligence matters more now

Four vendors, four different exit paths, and one shared lesson: tenure and brand recognition no longer predict that a vendor will still be operating, or still be honest, next quarter. A company that closes voluntarily and refunds customers (Science.bio) and a company that gets raided with no wind-down process at all (Amino Asylum) look identical from the outside right up until the moment they don't. The difference between those outcomes has consistently traced back to whether the underlying business was making accurate claims — about testing, about manufacturing location, about legal compliance — well before the closure happened.

That's the case for checking a vendor's documentation independently rather than relying on how long it's been around or how it ranks in search results, which we cover in our COA-reading guide and red-flags checklist.