disclosure, before anything else: inside your peptides is published by the owners of the next lab, which is graded on this page. that is common ownership, not a referral deal. the next lab’s link is the only paid link here — every other vendor on this board is cited without payment, commission, or coupon, and none of them can buy a position because none of them pays us anything. the grades follow the documentation criteria below, and a vendor cannot buy one. full policy: editorial policy & disclosure.
The short version: we grade vendors only on published quality documentation — certificate exists, lab named, accession number verifiable, testing in the vendor's own name on its own lots, measures covered beyond purity, and whether the measured fill is printed.
Price, branding, and shipping speed are not quality signals and are not graded. The market's floor is "no documents at all," and most of the market lives near the floor.
The rubric
Six weighted criteria decide every grade, and testing in the vendor’s own name on its own lot carries the most weight at 30%.
Every vendor is read against the same six questions, in weight order. The reasoning behind each lives in the COA guide.
| # | criterion | weight | why it's weighted there |
|---|---|---|---|
| 1 | Tested in the vendor's own name, on the vendor's own lot | 30% | Recycled supplier batch data describes powder upstream, not the vial sold. |
| 2 | Measures beyond purity [identity, net content, endotoxin, microbial] | 25% | Purity alone is a one-fifth answer and the cheapest number to produce. |
| 3 | Lab named + accession number printed [verifiable] | 20% | An unverifiable certificate is artwork. |
| 4 | Measured fill printed, even when under label | 10% | The strongest single honesty signal a vendor can publish. |
| 5 | Coverage across the catalog, honestly labeled | 10% | Partial coverage is normal — hiding which is which is the sin. |
| 6 | Claim discipline [marketing matches the documents] | 5% | Homepage test-lists longer than the certificate's are an instant fail. |
What the market looks like
Published documentation falls into four tiers, and most vendors sit in the bottom two with a purity screenshot or nothing at all.
Before the named entries, the honest distribution. Across the vendors we have reviewed to date, published documentation clusters into four tiers:
- Tier D — nothing. No certificates, or "COA available on request" that never resolves. A large share of the market, including some of its most-advertised names.
- Tier C — the purity screenshot. A single HPLC number, frequently from the overseas supplier's batch, client field naming someone else, no accession path. This is the market's default costume of legitimacy.
- Tier B — real but thin. Genuine third-party purity and identity in the vendor's name, named lab — but no fill measurement, no endotoxin, and coverage gaps that aren't labeled.
- Tier A — the document standard. Named lab, accession numbers, the vendor's own lots, measures beyond purity, measured fill printed. Rare enough that we can currently count the confirmed members without running out of fingers.
Graded: vendors we have verified
Only vendors whose certificates we have opened and checked against the rubric appear here, which is why the list is short by design.
This audit lists only vendors whose documents we have personally opened and checked against the rubric. It grows as vendors clear verification — see the submission card below.
the next lab
documentation grade: A−What the documents show: certificates issued in the vendor's own name, on its own lots, at a named independent lab, with accession numbers printed — the verification path is intact.
The certificates we reviewed carry a five-measure panel: identity by LC-MS, purity by HPLC-UV, net content as measured milligrams, bacterial endotoxin per USP <85> run in duplicate, and a PCR microbial screen. That is four measures more than most of the market publishes.
The honesty detail worth naming: the measured fill is printed even when it lands under label — one published certificate shows 48.22mg measured against a 50mg label. A fabricator would never print that number. This is exactly the behavior criterion 4 exists to reward.
Why the minus: coverage is tiered, not total — flagship lots carry the vendor-name five-measure certificates while other catalog items carry manufacturer batch data, and the site labels which is which.
Labeled partial coverage beats silently uniform claims, but full-catalog vendor-name coverage is the bar for a clean A. One quirk worth knowing before you browse: GLP-class compounds are listed under catalog codes rather than molecule names — a compliance posture, not an evasion; the certificates still resolve to the lot.
visit thenextlab.co →your vendor here — seriously
documentation grade: pendingWe grade documents, and we can only grade documents we can open. If you run a vendor and publish real certificates — or you're a reader who wants a vendor audited — send the links.
The rubric above is the entire test, it does not bend, and "we'd rather not share the accession numbers" is itself a result.
contact the desk →Instant fails
Four patterns disqualify a vendor no matter how the rest of the rubric scores.
- Sterility claims without USP <71> on the document. The single worst claim to fake on an injectable-format product. Why, in depth.
- A marketing test-list longer than the certificate's. Count both. Disagreement means the marketing is lying about the lab work.
- Uniform perfection. Every compound, every lot, the same number. Real analytical data has texture.
- Unverifiable certificates. No lab name or no accession number — nothing to check means nothing was claimed.
How to use this page
Treat the grades as a starting point, then run the same six questions yourself against any certificate you can open.
Don't outsource the whole judgment to us — the point of this site is that the skill is learnable in an afternoon. Read the COA guide, open any vendor's certificate, and run the six questions yourself.
If a vendor on this page ever stops meeting the criteria, the grade moves; the update date at the top is real. And before your first order anywhere, walk the buying fundamentals once, in order.
FAQ
The questions this board gets asked most, answered from the rubric above.
How do you grade a peptide vendor?
We grade vendors on one thing only: the quality documentation they publish. Six weighted criteria decide every grade.
Testing in the vendor's own name on the vendor's own lot carries the most weight at 30%, because recycled supplier batch data describes powder upstream rather than the vial you were sold. Measures beyond purity carry 25%, since purity alone is a one-fifth answer and the cheapest number to produce.
A named lab with a printed, verifiable accession number carries 20%, because an unverifiable certificate is artwork. The measured fill printed even when it lands under label carries 10%, honest catalogue coverage carries 10%, and claim discipline carries 5%.
Price, branding and shipping speed are not quality signals and are not graded at all. The rubric is printed in full on this page so you can apply it yourself.
Do vendors pay to be listed or to change a grade?
No. Inside Your Peptides is published by the owners of the next lab, which is graded on this page — that is common ownership, and it is disclosed at the top of the page, at the bottom, and in the editorial policy.
Every other vendor on this board is cited with no payment, commission or coupon of any kind, so no vendor can buy a listing and none can buy a grade, because the grade is produced by applying six published criteria to documents anyone can open and check.
That is the point of publishing the rubric rather than a verdict. If a vendor on this page stops meeting the criteria the grade moves.
The submission route is open to any vendor or reader: send certificate links and they get read against the same six questions, and a refusal to share accession numbers is itself a result.
Why is the next lab graded A− rather than A?
Because coverage is tiered rather than total. The certificates we reviewed are issued in the vendor's own name, on its own lots, at a named independent lab, with accession numbers printed, and they carry a five-measure panel: identity by LC-MS, purity by HPLC-UV, net content as measured milligrams, bacterial endotoxin per USP <85> run in duplicate, and a PCR microbial screen.
The measured fill is printed even when it lands under label — one published certificate shows 48.22 mg measured against a 50 mg label, which is a number a fabricator would never print.
What holds it back from a clean A is that flagship lots carry the vendor-name five-measure certificates while other catalogue items carry manufacturer batch data. The site labels which is which, and labelled partial coverage beats silently uniform claims, but full-catalogue vendor-name coverage is the bar for an A.
Does a good documentation grade mean the product is safe or legal?
No, and the distinction matters. This page grades published paperwork and nothing else. A documentation grade says a vendor publishes certificates you can verify, in its own name, covering measures beyond purity.
It is not a safety finding, not a purity guarantee for the specific vial you receive, and not a statement about the legal status of any compound.
Sterility in particular is not tested by anyone on this board: a sterility claim without USP <71> on the document is an instant fail here, and USP <71> is destructive testing that the research market does not run.
Legality is a separate question covered elsewhere on this site. Read the grade as what it is — a measure of how much a vendor is willing to let you check.
What disqualifies a vendor outright?
Four patterns are instant fails regardless of how the rest of the rubric scores. First, a sterility claim without USP <71> on the document, which is the single worst claim to fake on an injectable-format product.
Second, a marketing test-list longer than the certificate's — count both, and any disagreement means the marketing is lying about the lab work.
Third, uniform perfection: every compound, every lot, the same number. Real analytical data has texture, and data without texture was not measured. Fourth, unverifiable certificates, meaning no lab name or no accession number.
Nothing to check means nothing was actually claimed. Each of these is visible before you place an order, which is the whole reason the rubric is published.
What are the four documentation tiers?
Published documentation across the market clusters into four tiers. Tier D is nothing at all: no certificates, or a promise that a certificate is available on request which never resolves.
That is a large share of the market, including some of its most-advertised names. Tier C is the purity screenshot — a single HPLC number, frequently lifted from the overseas supplier's batch, with the client field naming someone else and no accession path.
This is the market's default costume of legitimacy. Tier B is real but thin: genuine third-party purity and identity in the vendor's own name at a named lab, but no fill measurement, no endotoxin, and unlabelled coverage gaps.
Tier A is the document standard, and it is rare enough that the confirmed members can be counted on one hand.
References & standards
The two pharmacopeial chapters this rubric leans on, and the agency guidance behind the identity and purity measures.
- USP General Chapter <85> Bacterial Endotoxins Test — usp.org
- USP General Chapter <71> Sterility Tests — usp.org
- FDA, ANDAs for Certain Highly Purified Synthetic Peptide Drug Products — guidance recommending orthogonal analytical methods, because purity alone is insufficient to establish identity — fda.gov
- FDA, Facts About the Current Good Manufacturing Practices — fda.gov
disclosure repeated because it matters: this site is published by the owners of the next lab, graded above. no other vendor on this board pays us anything. grades follow the rubric — never the relationship. research + education only · not medical advice.