How PeptideComps works

Vendors sell vials of different sizes and multi-vial kits. We read the size out of each product and variant title (mg, mcg, g, “10 × 5mg”, “kit of 10”, “Ten Pack”), multiply by the pack count, and divide the price by the total milligrams. That one number is what you compare. Capsules and tablets are dose × count; liquids and sprays use the stated bottle total.

$/mg falls as vials get bigger, so we compare vials of the same size with each other (a 10 mg vial against 10 mg vials). Every peptide page also lists the cheapest price at each size.

Water and syringes, bulk and wholesale listings, topical cosmetics, and different compounds that share a name (arginate or N-acetyl variants, fragments) are not compared. Named stacks (GLOW, KLOW, Wolverine, GH-secretagogue combinations) are compared only against the same stack, priced per mg of total powder, and only when every ingredient and the total amount can be read from the listing; blends with an unrecognised ingredient or an unclear breakdown are skipped. Ambiguous listings — for example “CJC-1295” with no mention of DAC — are skipped rather than guessed. Multi-vial kits stay out of headline prices but can be switched on.

A statistical check flags offers priced far from other listings of the same peptide and size (often a parsing quirk or a unit mix-up). They are hidden from headline prices by default and can be shown with one toggle, labelled “verify”.

PeptideComps is free to use. We may earn a commission when you buy from a vendor through some of our links, and we may offer vendors paid tools such as price-benchmarking reports. Neither affects ranking: vendors are ranked only by price per mg (or whichever sort you choose), and no vendor can pay to be listed higher, to be hidden, or to change a testing signal. Where we have an affiliate arrangement with a vendor the footer says so. The rule for which vendors are listed at all is the same for everyone and is described above.

Next to each vendor we show what is publicly known about their testing, compiled from a research directory. “COA claimed” means the vendor says it publishes certificates of analysis — a claim, not proof, since COAs can be copied or re-dated. “Tested” is a rating from independent third-party lab testing (Finnrick) and only appears where such tests exist; a small number of tests is weak evidence either way. “Flagged” marks vendors with reports of litigation, raids or shutdowns; these notes come from secondary sources and are frequently unverified. None of this is a recommendation.

We only list vendors that pass a reputation screen: no serious red flags (reports of litigation, raids or shutdowns), no failing independent test record (a Finnrick rating under 60% across five or more tests), and either a published-COA claim or an independent rating of 60% or more. Vendors also need a public product feed that permits automated access. A vendor added by hand is noted on its page. Passing this screen is not an endorsement.

PeptideComps does not verify purity, sterility or legality of any product, and nothing here is medical advice. Products are sold for laboratory research use only. Price is only one input — look for independent third-party testing before trusting any vendor.