Vendor ranking

Best peptide vendors, October 2026

Next Gen Peptides is the highest-scoring research-peptide vendor in this index as of October 2026, at 96.1 of 100 on 114 third-party certificates. The ten below are ranked on published evidence — certificates, named laboratories, disclosed prices and corporate details — and not on our opinion of them or on what anyone paid. The whole corpus behind this page is 648 certificates, each one linked.

Published 1 Oct 2026 · 56 vendors scored · 648 certificates · every figure computed from the live index

Edited by Slava Melikov, Research Editor · reviewed 1 Oct 2026

The top 10 this month

of 56 scored

#	Vendor	Score	Certificates	Compounds	Testing laboratory
1	Next Gen Peptides	96.1	114+114	28	ILS Laboratories· ISO 17025
2	Amino Club	92.7	23+23	12	Freedom Diagnostics Testing· ISO 17025
3	ZC Labs	91.3	39	19	ILS Laboratories· ISO 17025
4	Origin Labs	91	24+14	17	Freedom Diagnostics Testing
5	PeptidePlugs	90.7	70+70	34	Freedom Diagnostics Testing
6	Ascend Science	90.5	29+20	13	Kovera Labs and/or ILS Labs· ISO 17025
7	Modern Aminos	88.1	30	19	Vanguard Laboratory· ISO 17025
8	Bench Grade Peptides	86.8	53	27	AV Analytics
9	Hydro Research Peptides	85.9	32+13	22	ILS Laboratories· ISO 17025
10	Simple Peptide	84.9	30+2	24	Freedom Diagnostics Testing

A +n is certificates added to the index since 16 Sept 2026 — added to our record, which is not the same as newly published. Scores are 0–100, computed from stored data points rather than assigned. A laboratory is named only where the name on the certificate resolves to one we can identify; where it does not, the column says so rather than printing the string we read. Every certificate counted here is readable at /certificates, and the laboratories at /labs.

Best for a particular thing

Highest score
Next Gen Peptides
96.1 of 100, on 114 certificates covering 28 compounds.
Cheapest basket
ZC Labs
40% of the peer median across the compounds we price.
Most certificates
Next Gen Peptides
114 lot-level certificates on file, the largest published set in the index.
GLP-1 compounds
Next Gen Peptides
The highest-ranked vendor that both publishes certificates for and prices retatrutide, tirzepatide or semaglutide.
Accredited laboratory
Next Gen Peptides
The highest-ranked vendor whose testing laboratory holds ISO/IEC 17025 accreditation on file.

What changed since September

287 certificates entered the index since 16 Sept 2026, across 10 vendors. Next Gen Peptides added 114, PeptidePlugs added 70, Amino Club added 23, Vial Drop Labs added 22.

Most of that is one vendor, and it is worth being plain about why. Next Gen Peptides’s 114certificates are not newly published — they were on the vendor’s site the whole time, and our reader could not parse the layout their laboratory prints until this month. Their position here reflects evidence that already existed and which we were failing to count, not a change in what they publish. The same fix would raise any vendor using that laboratory.

What this page deliberately does not show is movement in the ranking itself. The index recomputes scores continuously but keeps no monthly snapshot of where each vendor stood, so there is no September table to difference against this one. Rather than reconstruct it from memory and present the result as measurement, this issue reports the standings as they are and the evidence that changed underneath them. A rank column with arrows in it would be the easiest thing on this page to fabricate.

How to check any of this

Every number above resolves to a document. A vendor’s profile lists each scored fact with the page it was read from and the date it was captured; each certificate has its own page showing the labelled mass, the assayed mass, the laboratory and the lot, with a link to the original PDF or scan. Where a laboratory runs a public lookup, the certificate page links into it, so the document can be verified against the lab rather than against us.

The full dataset is downloadable: certificates as CSV, vendors as CSV, and the whole index as JSON. If a figure here disagrees with the document behind it, the document is right and we want to know.

Questions

Who is the best peptide vendor in October 2026?

Next Gen Peptides, at 96.1 of 100. They publish 114 lot-level certificates across 28 compounds, tested at ILS Laboratories. "Best" here means best-evidenced: the score is computed from what a vendor publishes and can be checked, not from reviews or reputation. A vendor can be perfectly good and score lower simply by publishing less.

How are these peptide vendors ranked?

On six weighted criteria — testing transparency, documentation depth, price and value, track record, business transparency and commercial clarity — computed from stored data points, each of which links to the document it came from. Nothing is scored by hand. 648 certificates and every vendor fact behind this ranking are published at /certificates and on each vendor's profile, and the raw data is downloadable as CSV and JSON.

Are the most expensive peptide vendors the best ones?

No, and this index gives no evidence for it. ZC Labs runs at 40% of the peer median and still ranks 3 of 56. Price carries 20 of the 100 points and it rewards being cheap for comparable evidence, not being cheap outright — a vendor that publishes nothing scores nothing on testing regardless of price.

Which peptide vendor publishes the most certificates?

Next Gen Peptides, with 114 lot-level certificates in this index. Volume is not quality on its own — a certificate matters when it names the laboratory, the lot and the assayed mass against the labelled mass — but a vendor publishing per-lot documents at that scale is making a much larger claim that can be checked against it.

How often does this ranking change?

It recomputes hourly from stored data, and vendors are re-verified on a rolling monthly cycle. A score moves when the evidence behind it moves — a new certificate, a price change, a fact going stale — and never because a page was edited. The figures on this page were computed when it was last built, from the live index.

Where to go next

The live ranking — this table, recomputed hourly
Price per milligram — what each vendor charges, compared
Every certificate — the corpus behind the scores
The laboratories — who signs these documents

PepIndex earns affiliate commission from some vendors listed here. Commercial relationships are structurally excluded from the score — they cannot raise or lower one — and are disclosed in full. Research peptides are not medicines and nothing here is medical advice.