How rankings work

Peptide Library does not sell peptides and does not sell ranking placement. Vendor scores shown on the site come from user reviews stored in our vendor review aggregates.

Score formula

For each vendor, the displayed score is the average of that vendor's reviews:

If a review includes an overall rating (1–5), that overall rating is used.
If a review has no overall rating, the average of its detail ratings is used (packaging, appearance, label accuracy, COA availability, COA transparency, research satisfaction, shipping speed, order accuracy, support, payment smoothness, communication, and value).

The published score is the mean of those per-review values. We also show how many reviews exist and how many are marked verified when that data is available.

What rankings are not

Not a clinical recommendation or safety rating.
Not an endorsement for human use.
Not a paid advertising ranking. Coupons or affiliate links do not change the score.

Prices

Price per mg is list price divided by vial size in milligrams when both values are known from the vendor listing. Prices change when vendor catalogs change. Always confirm the current price on the vendor's site.

Questions about methodology: contact support.