Method

How I evaluate research peptide vendors — the seven criteria, the cap at 9.9, what's in scope, and what isn't.

How I evaluate vendors

Each ranked piece on this site works the same way. I pick a specific question — "who actually sells pre-filled pens?", "which vendors offer real curated multi-peptide kits versus volume packs?" — and pull together every US-facing vendor I can credibly evaluate against it. I read their product pages, lab archives, shipping policies, and customer reviews. I build a spreadsheet. I score, I cap, I write it up.

The scoring is not pseudo-precise. The intention is to communicate a ranked judgment that a researcher can use to narrow a shortlist, not to imply that "8.4" means anything different from "8.5" in some absolute sense. The numbers are an honest summary of how I weighted the seven criteria below — nothing more.

The seven criteria I weight

1. Catalog breadth. How many distinct compounds does the vendor stock? A 67-SKU catalog tells me something different from a 12-SKU one — about commitment, sourcing relationships, and depth of the underlying program.
2. Format diversity. Vials, pens, capsules, blends, kits, nasal sprays, powders, oral liquids. Format matters because protocols vary; a vendor that offers BPC-157 in five formats is solving a different problem than one selling lyophilized vials only.
3. Documentation. Per-vial CoA with QR linkage to a public Lab Hub is the current ceiling. PDF archives are next. Manual lookup is acceptable. No CoA at all is disqualifying. I weight the analytical panel too: HPLC alone is the floor; HPLC plus mass spectrometry, endotoxin, sterility, and heavy-metals screening is the ceiling.
4. Shipping operations. Same-day or next-day cutoff, insulated packaging for temperature-sensitive compounds, US-domestic only versus international, and stated stability windows for lyophilized material.
5. Payment options. Card-only is a friction signal. Card plus crypto plus wire plus check tells me the vendor takes institutional and individual buyers seriously and has stable processor relationships.
6. Pricing transparency. Published pricing on product pages, with clear per-vial costs and no "request a quote" gates for standard SKUs. Bulk pricing transparency is a bonus.
7. Customer signals. Trustpilot scores, review counts, Reddit community sentiment, and the presence (or absence) of unresolved complaints. A 4.9 across 800 reviews is meaningful; a 4.9 across 12 reviews is not.

Why scores cap at 9.9

I cap at 9.9 because no vendor is perfect. The half-step gap from 9.9 to 10.0 acknowledges that documentation can always improve, format depth can extend, and shipping can be faster. Reserving a perfect score also signals that the ranking is editorial judgment, not a mechanically computed grade.

What sources I use

Vendor websites are the primary source — product pages, lab archives, shipping and payment policy pages, FAQ sections. Public CoA libraries (vendor Lab Hubs, embedded PDFs, third-party verification pages from Janoshik or Finnrick) are read directly. Customer reviews come from Trustpilot, Reddit threads, and any community feedback the vendor links to. Where a claim is unverifiable from public sources, I note it as a vendor claim rather than treating it as established fact.

What I don't do

I do not test peptides in a lab. This is journalism, not analytical chemistry. I do not own an HPLC, I am not a credentialed biochemist, and I will not pretend to be one. When a vendor publishes a third-party CoA, I read it; when one is missing, I say so. The rigor of vendor documentation is part of what I evaluate, but I do not independently verify the underlying chemistry.

I also don't do undercover buying for every piece. Where I have made purchases I will say so. Where I haven't, the writing is based on publicly available documentation and customer reports, and I label conclusions accordingly.

Update cadence

Ad hoc. I publish when I have something substantive — typically when a vendor introduces a new format, when documentation standards shift, or when a question accumulates enough requests that I should answer it in writing. There is no editorial calendar. There is no quota. The "writing" page lists pieces in reverse chronological order.

One last note

If you disagree with a ranking, or know of a vendor I should cover, email hello@reyesnotes.site. I read every email and update pieces when warranted. Corrections are noted at the bottom of the affected article.