Preview data. Scores are placeholder values until our first round of testing is complete. They are not measurements of any vendor. Read more
Independent purity results, measured delivery times, and transparency checks across the vendors people actually order from.
40% of the score
81%
of 154 independent samples met the standard
Every sample is bought the way you would buy it, sent to an independent lab, and judged against one published standard. A vendor is scored on how often its recent samples pass, with new results counting for more than old ones.
25% of the score
18 of 20
vendors print a lot number on the certificate that matches the vial
Transparency you can check before paying: whether the certificate is public, whether the lot matches the vial, whether the lab is named, and whether the report can be re-checked on the lab’s own site. Each answer is worth a fixed number of points.
20% of the score
3 days
median order to doorstep across the board, fastest 1 day
Measured in business days from order to doorstep for US addresses, not the dispatch promise on the checkout page. Tracking, carrier choice, and same-day cutoffs are listed on every vendor page.
15% of the score
0.75x to 1.44x
the market median price per milligram, across every listing we track
Prices are normalised to dollars per milligram so a 5 mg vial and a 10 mg vial compare fairly. Cheap is only good when the vial passes. Value carries the smallest weight for that reason.
Top ten by overall score. The full list, product views, and filters live on the rankings page.
Updated Oct 27, 2026
Overall = 40% purity, 25% trust, 20% delivery, 15% value. Why those weights
An overall rank hides a lot. A vendor that nails retatrutide can still underfill BPC-157. Pick the compound first, then look at who leads it.
Metabolic
Metabolic
Recovery
Metabolic
Skin and longevity
Recovery
Skin and longevity
Growth hormone axis
Growth hormone axis
Growth hormone axis
Metabolic
Other
A sample either meets all four conditions or it fails. There is no partial credit and no blended score for a single vial. The vendor score is simply how often its recent samples pass.
Read the full standard99.5%
Measured by HPLC at an independent lab. A 99.0% vial is a clean result by most standards. Here it is a fail.
±25%
Measured quantity against the label claim. A 10 mg vial that holds 7 mg is underdosed, however pure the powder is.
MS
Mass spectrometry has to find the compound the label promises. Purity means nothing if it is purity of the wrong molecule.
Lot
The lot number on the certificate has to match the lot printed on the vial you receive. Website-only claims do not count.
New lab reports land every week and move the board the day they are published. Each row links to the vendor it belongs to.
See the rankingsSamples are purchased from the vendor the same way a customer would, then sent to an independent laboratory for HPLC purity, mass spectrometry identity, and quantity. We also fold in results from public testing databases when the sample provenance is documented. Vendor-supplied certificates are shown on the vendor page but never count toward the score.
The standard is 99.5% or higher. That is a deliberately high bar, because the vendors at the top of the board clear it routinely and the difference between a 99.0% and a 99.6% result is usually a difference in synthesis quality or cleanup, not measurement noise.
Scores are recomputed whenever new results are published, normally once a week. Newer results carry more weight than older ones, so a vendor that fixes a problem can climb within a couple of months, and one that slips will fall just as fast.
No. Every score on the site is computed from the inputs printed on the vendor page using the formula on the methodology page. If you recompute it by hand you will get the same number.
No. Everything here refers to compounds sold for laboratory research. The site compares vendors on measurable quality and service. It does not tell anyone to buy, possess, or use anything.
Probably. Send the name and site to hello@ratemypeps.com. Vendors are added once there is enough independent test history to score them fairly, which usually means a minimum of three results.
Send the name and a link. Vendors join the board once there are enough independent results to score them.
