How the score works
Every supplier page shows the same six factor scores and the same weighted total. This page is the formula, in full, so you can disagree with it precisely.
The six factors
| Factor | Weight | What feeds it |
|---|---|---|
| Testing & certificates | 35% | Whether independent testing is stated (yes / limited / no), whether certificates are open to the public, whether they are tied to a lot, whether a laboratory is named and appears to hold ISO/IEC 17025 accreditation, and which methods are shown (HPLC, mass spectrometry, endotoxin, sterility). |
| Transparency | 20% | Research-use-only labeling, a public email, phone and street address, a stated location and founding year, a reachable certificate page, and a written returns policy. |
| Track record | 15% | Years operating, trust-site score and review volume where a profile exists, positive and negative signals from the fact sheet, forum presence, and a heavy penalty for a public FDA warning letter. Closed suppliers score zero. |
| Catalog | 10% | Approximate number of listings, number of formats (vials, pens, capsules, nasal, bulk, blends) and breadth of notable products. |
| Pricing | 10% | Price tier, the listed price of a reference item (BPC-157, 5 mg) relative to the median across suppliers, free-shipping threshold, and whether prices are listed openly. |
| Ordering & service | 10% | Card acceptance and number of payment methods, stated dispatch time, international shipping, named carriers, returns and guarantee policies. |
How a factor becomes a number
Each factor starts at zero and adds fixed points for each verified field, then is capped at 100. For example, in Testing a supplier gets 40 points for stating independent testing, 15 more if certificates are public, 12 more if they are lot-specific, 8 for naming one laboratory or 14 for naming two, 6 if a named laboratory appears to hold ISO/IEC 17025 accreditation, and 3 to 4 points for each method shown on the certificates (HPLC, mass spectrometry, endotoxin, sterility). A supplier that publishes everything reaches 100; most reach 80 to 90. The weighted total is the sum of factor × weight, rounded.
Track record deducts points only for substantive negatives such as a removed trust-site profile, a regulator's letter or a missing company identity. Cosmetic site problems (a mistyped phone number, an inconsistent price display) are recorded on the fact sheet and already cost points in transparency or service, so they are not deducted twice.
"Not verified" never earns points. If a supplier gates its certificates behind a login, we cannot verify them and they score as not public. That is deliberate.
What we leave out
- Our own lab tests. We do not test products. Independent testing we can cite beats testing we would have to ask you to trust.
- User reviews and star ratings. None are collected, displayed or marked up. See the editorial policy.
- Anything about use. Every listed supplier sells materials labeled for laboratory research only, and the score has no factor for anything else.
- Referral status. Whether a link earns the site money is disclosed and plays no part in the formula.
Data collection and updates
Facts are collected from each supplier's own public pages (home, product, testing, about, contact, shipping) and from public records (FDA warning letters, trust-site profiles, business registries). Each supplier page lists its sources. Facts are re-checked on a rolling basis; the table is regenerated when data changes and every page shows the regeneration month.
The full dataset is downloadable as CSV and JSON on the open data page so anyone can reproduce the ranking.
Frequently asked questions
Can a supplier pay to improve its score?
No. The score is a fixed formula applied to the same fields for every supplier. The only way to move it is to change a fact we can verify, such as publishing lot-level certificates.
Why not use customer reviews?
Review counts in this category are easy to buy and easy to lose: several suppliers have had trust-site profiles removed. Where a profile exists we use it as one input to track record; we never collect reviews ourselves.
Do you test products?
No. We read what suppliers publish and what regulators publish. A certificate issued by an accredited third-party laboratory for a specific lot is the evidence we weight most.
How do I correct a fact?
Use the contact page with a link to the supplier page that shows the correct information. Corrections are applied at the next regeneration and the "updated" date changes.