Best suppliers with public certificates of analysis

Licensed Peptides names two accredited laboratories and keeps three separate document libraries, which puts it near the top of our index for paperwork.

Core Peptides publishes exactly the kind of certificate we want every supplier to publish: lot-specific, dated, from an accredited laboratory and open to anyone.

Ascension Peptides publishes two lot-level certificates per product from named laboratories, with endotoxin, sterility and heavy metals on the same document, which puts it near the top of our index for paperwork.

Paramount Peptides offers a named laboratory, a lot-numbered certificate and more than twelve years in the business, with a claim of in-house synthesis that few rivals make.

Koi Peptides has a lot-searchable certificate library, two US warehouses and a retest-and-refund promise, which is most of what a lab buyer wants.

A SARMs-first Connecticut company with two named laboratories, certificates you can open without an account and the longest money-back window in this group at 60 days.

BioLongevity Labs documents its testing better than most, names three outside laboratories and keeps an open batch library with endotoxin reports.

A young Texas company with one of the largest open, dated certificate archives in this group, free US shipping on every order and a published address, phone and legal name.

Alpha Peptides is a 2025 start-up whose batch-coded, outside-hosted certificates are better than its age suggests.

Evolve Peptides names three laboratories, shows lot-specific certificate and endotoxin images on the product page and backs purity with a 200 percent guarantee.

Alpha Labs Peptides pairs some of the lowest vial prices in our index with an open, dated certificate library that reaches into endotoxin and sterility.

A long-running supplier that takes cards, ships internationally and knows how to publish a proper lot-numbered certificate, then stopped doing so in 2023.

Biotech Peptides puts a lot-numbered, dated certificate from a named laboratory on its product page, which is more than most suppliers manage, and then tells you almost nothing about the company, the carriers or how to pay.

Nexaph gives kit buyers a low per-vial price, a named laboratory and a live review profile, and cannot decide whether it is a US facility or a Shanghai company.

If you need the pen format and want a lot-numbered certificate from an accredited lab, with endotoxin and sterility data on top, this is one of the easier recommendations in the group.

The best-linked certificates in this group, straight from the product page to Janoshik's own verification record, paired with an independent record in which half of Finnrick's tests failed and a company that publishes no address, phone or owner.

Limitless Biotech publishes something rare, per-lot certificates with sterility and endotoxin results, and then hides its prices behind an application, names no laboratory, and keeps its address and phone off its own site.

Some of the most traceable batch certificates in this group, from a company that will not tell you its address, phone number or name.

Blue Sky Peptide is a long-running budget supplier with a free certificate library and one of the lowest free-shipping bars we have seen.

Liberty Peptides shows you purity and endotoxin figures for 71 samples and never tells you which laboratory produced them.

A UK SARMs-first shop with budget peptide prices, a real street address and phone, card payment and a 14-day money-back window.

One of the better certificate libraries in this group and a genuine 30-day return window with a prepaid label, weighed against an FDA warning letter from December 2024 whose named products are still on the shop page.

A capsule-heavy research-chemical store with one of the larger public lab-results pages in this group and a purity refund you could actually claim, carrying an FDA warning letter from December 2024 and a returns policy that excludes peptides and adds fees.

Open certificates from two named laboratories and free US shipping with no minimum, on a mixed SARMs-and-peptides catalog that carries a 2021 FDA warning letter, files its certificates by date rather than lot, and has no returns policy at all.

Geo Peptides has one of the lowest BPC-157 prices we recorded and almost nothing behind it: certificates without a laboratory, lot or date, a text-only phone number for contact, and a Trustpilot record dominated by orders that did not arrive.

Loti Labs is one of the easier suppliers to order from, with free shipping from $99, card or ACH payment and a 30-day refund on unopened product.

Extreme Peptides has traded since 2010, answers a phone, takes card, Bitcoin and ACH and ships free from $99.

NuScience Peptides received an FDA warning letter dated August 24, 2026, and the address on that letter is not the one on its website.

A registered UK company trading since 2012, with budget GBP prices and card checkout, that openly declines to use third-party laboratory testing.

Direct Peptides offers the widest format range and the longest shipping reach in our index, backed by the thinnest testing record: one certificate image from 2023 with no lot and no laboratory, no published address, and no returns.

Card payments and a certificate page you can open without logging in, attached to certificates with no lot numbers or dates, testing done in-house, and a company that says it is registered in Panama and gives no address.