Where to Buy Research Peptides in 2026 — Post-Shutdown Vendor Guide

The research peptide supply chain looks very different in 2026 than it did 18 months ago. Multiple vendors have shut down, been raided, or received FDA warning letters. If you're looking for a reliable peptide supplier, here's what changed and what to look for now.

What Happened: The 2024–2026 Vendor Shutdowns

Three of the largest US peptide vendors ceased operations between late 2024 and early 2026:

Peptide Sciences voluntarily shut down in March 2026 after more than a decade of operation. No public explanation was given, though the closure came amid escalating FDA enforcement against the broader research peptide industry.

Science.bio went offline in January 2026. The site returned a blank page, then disappeared entirely. No advance notice was provided to customers.

Amino Asylum shut down in June 2025 after an FDA warehouse raid. The site went offline within days.

In addition, multiple vendors received FDA warning letters in December 2024, including Prime Peptides, SwissChems, and Xcel Peptides. The International Trade Commission issued exclusion orders against several vendors importing tirzepatide. See our full Vendor Shutdown Tracker for the complete timeline.

Why Vendors Are Shutting Down

The vendors that have been shut down or warned share common patterns. They made explicit or implied therapeutic claims about their products. They sold compounds like semaglutide and tirzepatide with human-use implications. They lacked compliance infrastructure such as buyer certifications, RUO labeling, or documented anti-diversion programs. Understanding these patterns helps identify which remaining vendors are operating sustainably and which may face similar enforcement.

How to Evaluate a Peptide Vendor in 2026

The shutdown wave has made vendor evaluation more important than ever. Here's what to verify before placing an order:

Published third-party COAs. This is the single most important factor. The vendor should publish HPLC chromatograms and mass spectrometry data for every batch, performed by an independent laboratory — not in-house testing. The COA should be downloadable from the product page before purchase, without requiring an account or email.

RUO labeling and zero therapeutic claims. Every product page, vial label, and marketing material should be clearly labeled "Research Use Only — Not for Human Consumption." Any vendor making claims about health outcomes, dosing protocols, or therapeutic applications is operating outside the regulatory framework that allows research chemical sales.

HPLC purity ≥98%, ideally ≥99%. Reversed-phase HPLC should show a dominant peak at the expected retention time with area percentage ≥98%. Lower purity often indicates incomplete synthesis, degradation, or contamination with truncated sequences.

Mass spectrometry identity confirmation. The COA should include ESI-MS or MALDI-TOF data showing the observed molecular weight matches the theoretical MW of the target sequence, typically within ±0.1 Da for small peptides.

Verifiable business information. US-based address, contactable email or phone, and a compliance or terms page that outlines their regulatory posture. Anonymous vendors operating through only a web form are higher risk.

For a comprehensive scoring framework, see our How to Choose a Peptide Vendor guide.

What About Science.bio?

Science.bio is permanently shut down as of January 2026. The domain is offline. No customer data migration, order fulfillment, or communication was provided. There is no successor operation. If you were a Science.bio customer, you'll need to find a new vendor — the evaluation criteria above apply.

What About Peptide Sciences?

Peptide Sciences ceased all operations in March 2026. The website is no longer functional. The closure appears to be voluntary rather than enforcement-driven, but the result is the same: no new orders, no existing order fulfillment, and no communication timeline. Former Peptide Sciences customers can review our switching guide for product mapping and a 15% discount with code SWITCH15.

The Current Vendor Landscape

The 2024–2026 enforcement wave has consolidated the market significantly. The vendors that continue to operate tend to share several characteristics: strict RUO compliance, third-party analytical testing, transparent pricing, and no GLP-1 or compounding pharmacy positioning. When evaluating any vendor, apply the criteria above — published COAs, independent testing, molecular identity confirmation, and clear regulatory labeling.

How Pepta Labs Is Structured

Pepta Labs was launched with the post-2024 regulatory environment in mind. Every compound meets a ≥99% HPLC purity standard, verified by an independent third-party lab. Full COAs with HPLC chromatograms and ESI-MS data are published on every product page before purchase. All products carry RUO labeling. We maintain a documented compliance policy, buyer certification framework, and anti-diversion program. No therapeutic claims appear anywhere on the site.

Available Compounds — All Third-Party Verified

Most popular: BPC-157 10mg ($49.16) · TB-500 10mg ($47.31) · GHK-Cu 50mg ($41.79) · Ipamorelin 5mg ($33.79)

Nootropic: Semax 30mg ($32.56) · Selank 10mg ($33.79) · DSIP 5mg ($29.49)

Anti-aging: Epithalon 50mg ($30.72) · NAD+ 500mg ($70.66) · Thymosin Alpha-1 10mg ($61.42) · Kisspeptin 5mg ($41.79)

More: CJC-1295 DAC ($67.57) · CJC-1295 no DAC ($49.16) · MOTS-c 10mg ($52.22) · Melanotan-I ($30.72) · Melanotan-II ($35.63) · KPV ($47.31) · SS-31 ($52.22)

Bundles: Wolverine Bundle — BPC-157 + TB-500 ($79.99) · GLOW 70 ($114.99) · KLOW 80 ($159.99)