Methodology
How we grade peptide vendors
We grade a peptide vendor only on independent lab results. Not on its own certificates, its marketing, or whether it pays us. This page explains every number on a vendor review.
Where the test results come from
Most results come from the public testing program run by Finnrick Analytics, which buys vials from vendors and sends them to analytical labs. We import each published result with its lab, batch number, test date and certificate.
Every test on a vendor review links to its original certificate. If a number looks wrong, check it at the source.
A vendor's own certificates of analysis don't count toward its grade. The vendor chooses which batch to send and which report to publish, so they can't tell you what a random order contains.
What each test measures
- Identity
- Is the compound in the vial the one on the label? A failed identity test means the sample was something else, or nothing measurable.
- Purity
- What share of the sample is the labelled peptide, usually measured by HPLC. Research listings commonly claim 98–99% or higher.
- Quantity
- How many milligrams were actually in the vial compared with the amount printed on it. A 10 mg vial holding 7.8 mg is a 78% fill.
Product grades, A to E
Each published test carries a score out of 10 that reflects its identity, purity and quantity results. A product's grade comes from the average of its scores:
| Grade | Average score | Reads as |
|---|---|---|
| A | 9.0 or higher | Great |
| B | 8.0 to 8.9 | Good |
| C | 7.0 to 7.9 | Okay |
| D | 6.0 to 6.9 | Poor |
| E | below 6.0 | Bad |
A vendor's overall grade averages its products, weighted by how many tests each one has. One good batch can't carry a shop with twenty tested products.
The lab record rating
Every vendor review opens with a lab record rating. It summarises how much independent evidence exists and what it shows:
- Strong
- 10 or more independent tests, no more than 5% of measured lots more than 5% under label, median purity of 99% or higher, and no product graded E.
- Mixed
- 10 or more independent tests that miss at least one Strong threshold — for example more under-filled lots, lower median purity, or a product graded E.
- Limited
- 1 to 9 independent tests. Too few samples to describe the shop as a whole.
- No independent tests yet
- No independent lab results on file for this vendor.
“Filled to label” means the measured amount was no more than 5% below the label.
What a grade can't tell you
- It describes tested batches. A new batch can be better or worse, so check the test dates.
- It isn't a verdict on the business. Shipping, payment safety and customer service aren't measured in a lab. Our vendor verification checklist covers those.
- No tests means no grade. An ungraded vendor isn't bad. It just can't be verified here yet.
Partners and independence
Some vendor links are affiliate links, and partners are labelled on their reviews. A partnership never changes a test result, a grade or a lab record rating.
Who runs Peptide Vendor Reviews and how it makes money is on the about page.