PepsTracker is an independent price-comparison site. We do not sell, manufacture, or ship any product. We track what 26 research-peptide vendors publicly list, normalize every listing to cost per milligram, and show which source is cheapest for a given compound.
Vendors sell the same compound in different vial sizes, so headline price is not comparable. For every listing we compute:
cost per mg = (list price x (1 - discount)) / milligrams
Each vendor's public discount code is applied before ranking, because that is the price a buyer actually pays. For a compound sold in several vial sizes, we use the size with the lowest cost per mg. This is why the ranking can differ from a simple price sort.
Prices are read from each vendor's own public storefront - product pages, catalog feeds, or store APIs. We do not accept vendor-submitted pricing. When a vendor's site is unreachable or blocks automated access, that vendor's prices are updated manually and may lag.
Cost per mg reflects list price with the standing discount code applied. It does not model buy-one-get-one offers, first-order-only promotions, bundle pricing, shipping, or tax. Where a vendor runs a standing BOGO, we label it on that vendor's card rather than folding it into the ranking, so every vendor is compared on the same basis.
Some vendor links are affiliate links. Affiliate status has no effect on position in any comparison - ordering is a pure cost-per-mg sort.
If a price here is wrong, it is either stale or a scraping error. Both are worth reporting - the fastest fix is to send the vendor, compound, and the correct listing.
All products referenced are research chemicals intended for laboratory use only. Nothing on PepsTracker is medical advice. Last reviewed 2026-07-28.