October 2026 ranking · 49 suppliers

The best research peptide suppliers, ranked on what can be checked

We read every supplier's certificates, company pages and regulatory record, then score them with one published formula. No user reviews, no pay-to-rank, every fact linked to its source.

See the full ranking How the score works

Scores are editorial and computed from public facts. Every supplier listed sells materials labeled for laboratory research use only.

Top 5 right now Score /100

Core PeptidesLot-level public certificates · US80/100 2

Paramount PeptidesLot-level public certificates · US79/100 3Ascension PeptidesLot-level public certificates · US76/100 4

Koi PeptidesLot-level public certificates · US76/100 5

Licensed PeptidesLot-level public certificates · US75/100

49suppliers scored this month

31publish certificates openly

23testing laboratories named

7FDA warning letters on record

Top 10 suppliers, October 2026

All 49 ranked →

#	Supplier	Score	Third-party testing	Public COAs	Lot-level	Reference price	Based
Best overall · October 2026
1	Core Peptidescorepeptides.com	80/100	Yes	Yes	Yes	$52	US	Review Visit site
2	Paramount Peptidesparamountpeptides.com	79/100	Yes	Yes	Yes	—	US	Review Visit site
3	Ascension Peptidesascensionpeptides.com	76/100	Yes	Yes	Yes	—	US	Review Visit site
4	Koi Peptideskoipeptides.com	76/100	Yes	Yes	Yes	—	US	Review Visit site
5	Licensed Peptideslicensedpeptides.com	75/100	Yes	Yes	Yes	—	US	Review Visit site
6	Sports Technology Labssportstechnologylabs.com	75/100	Yes	Yes	Not verified	$54.99	US	Review Visit site
Best budget pick
7	Alpha Labs Peptidesgoalphalabs.com	72/100	Yes	Yes	Not verified	$20.99	US	Review Visit site
8	Alpha Peptidesalpha-peptides.com	72/100	Yes	Yes	Yes	—	US	Review Visit site
9	BioLongevity Labsbiolongevitylabs.com	71/100	Yes	Yes	Yes	—	US	Review Visit site
10	Evolve Peptidesevolvepeptides.com	71/100	Yes	Yes	Yes	$39.90	US	Review Visit site

Reference price = the supplier's listed price for BPC-157, 5 mg, where a like-for-like listing exists. Third-party testing, public and lot-level certificates are read from the supplier's own pages.

Best supplier for your situation

All shortlists →

3 qualify

What goes into a score

Full methodology →

Testing & certificates · 35%

Independent lab named, lot-level certificates anyone can open, methods shown.

Transparency · 20%

A real address, phone, founding year and a research-use-only disclaimer.

Track record · 15%

Years operating, trust-site history, and a heavy penalty for FDA warning letters.

Catalog · 10%

Breadth of listings and formats: vials, pens, capsules, blends, bulk.

Pricing · 10%

Listed prices against the field median on a reference item, free-shipping threshold.

Ordering & service · 10%

Card acceptance, dispatch times, carriers, returns and guarantees.

Lot-level, public certificates separate the top of the table

The highest-scoring suppliers publish a certificate of analysis for each production lot, signed by a named independent laboratory, that anyone can open before ordering. A single undated "sample" report, or certificates handed out only after purchase, score lower on the heaviest factor.

How to read a certificate · Suppliers with lot-level testing

Warnings and closures

7 tracked suppliers carry a public FDA warning letter and 8 have closed. Both pull the track-record factor down hard and are listed with dates and source links.

See the warnings page

Also scored this month

Full table →

Pure Peptide LabsUS · third-party tested · public COAs71/100

Simple PeptideUS · third-party tested71/100

Peptide PerfectionUS · third-party tested · public COAs70/100

Biotech PeptidesUS · third-party tested · public COAs69/100

Verified PeptidesUS · third-party tested · public COAs68/100

Limitless BiotechUS · third-party tested · public COAs67/100

Guides for lab buyers

All guides →

Endotoxin and Sterility Testing Explained: LAL, USP <71> and How They Appear on a COA

What LAL endotoxin tests (USP 85) and USP 71 sterility tests report for research peptides, why HPLC purity covers neither, and how each appears on a COA.

How to Check an FDA Warning Letter for a Peptide Supplier

Where the FDA publishes warning letters, how to search by company, what a letter does and does not establish, and how this site records them in supplier data.

How to Read a Certificate of Analysis for Research Peptides

Section-by-section guide to a peptide certificate of analysis: header, lot number, method, result, laboratory signature, and what a vague COA leaves out.

How We Collect Supplier Facts: Pages Read, Fields Captured, and the Open Dataset

The data-collection process behind peptideranking.org: pages read, fields captured, how not verified is handled, the CSV and JSON dataset at /data/, corrections.

Frequently asked questions

How are peptide suppliers ranked here?

Each supplier gets six factor scores computed from facts on its own public pages and in public records: testing and certificates (35%), transparency (20%), track record (15%), catalog (10%), pricing (10%) and ordering and service (10%). The weighted total is the score out of 100. The full method is on the methodology page.

Are these user reviews?

No. Scores are editorial and formula-based. We do not collect or display customer reviews or star ratings, and we do not mark pages up with review schema.

What matters most when picking a research peptide supplier?

Whether an independent laboratory tested the specific lot you receive, and whether you can read that certificate without buying first. That single factor carries more weight than anything else in our model.

How often is the ranking updated?

Facts are re-checked on a rolling basis and the table is regenerated whenever the data changes. The month shown on each page is the last regeneration.

Does the site earn money from suppliers?

Some outbound links may carry referral codes and the site may be paid when a reader buys through them. Referral status never changes a score, which is computed from the same formula for every supplier. See the advertising disclosure.