Peptide questions, answered with data
Short answers to what people ask most about peptide prices, vendors and lab reports. Figures come from the same data as the rest of PeptideCompare and update with it.
Prices
How much do research peptides cost?
Prices differ by compound. Right now: GHK-Cu from USD 0.019 per mg (median USD 0.450); Tesamorelin from USD 1.05 per mg (median USD 4.95); Retatrutide from USD 0.425 per mg (median USD 3.15). Each price guide lists every tested vendor's price per milligram, and the statistics page shows cheapest and median prices side by side.
Why compare price per mg instead of price per vial?
Vials come in different sizes and kits hold different numbers of vials, so sticker prices can't be compared directly. Price per milligram puts every listing on the same scale. How price per mg is worked out.
Are coupon codes included in the prices shown?
A coupon that takes a flat percentage off with no conditions is already applied, and the list price is shown next to it. Codes with conditions (first order, minimum spend) are shown but not applied. All current coupon codes.
Where do the prices come from?
From each vendor's own website. We compare 7,206 listings from 278 vendors; a price can change between our reading and your visit, so check the vendor's page before ordering.
Vendors and lab testing
How are peptide vendors rated?
By a metascore that combines independent lab tests of vials bought the way a customer would, whether the vendor's own lab reports hold up, and whether its claims match what buyers measured. How the metascore works and the current ranking.
What is a COA and how do I read one?
A certificate of analysis is a lab report for one batch: it should name the lab, the sample, the batch and the measured purity and amount. How to read a COA walks through a real one, and the labs directory shows which labs issue them.
Why are some vendors banned?
10 vendors are banned for fake or doctored lab reports: reports issued to another company, edited documents or results for a different compound. Their products and ratings are removed and they are listed on the Vendors page.
Does PeptideCompare sell peptides?
No. PeptideCompare is a comparison site. It links to vendors' own websites and never handles orders, payments or shipping.
Do affiliate links change the rankings?
No. Some links earn a commission and are labelled as affiliate links, but rankings use price per mg and lab evidence only. Affiliate status is never an input.
How do I report a vendor that took my money?
Use the scam report form. Reports are tied to a verified email, reviewed before publishing, and the vendor can respond.
Mixing math and units
How much bacteriostatic water goes into a vial?
That is arithmetic that depends on the vial size and the strength wanted. The 274 mixing charts show the strength for each amount of water, and the reconstitution calculator handles other numbers. These are calculations, not dosing advice.
What do mg, mcg, IU and units mean?
Milligrams and micrograms measure mass (1 mg = 1,000 mcg); units on an insulin syringe measure volume (100 units = 1 mL); IU is an activity measure specific to each substance. Units explained and the glossary.
Research and legal status
Are the peptides listed here FDA approved?
Most are sold for laboratory research only and are not approved medicines. A few, such as semaglutide, tirzepatide and tesamorelin, are approved prescription drugs in specific forms. Each price guide states the compound's status, and the compounding page tracks what US pharmacies may compound.
How do I know whether a peptide has real evidence behind it?
101 compounds have a graded review in the research library, from A (strong human evidence) to D (little or none for the exact compound), with the papers, sample sizes and results listed. Registered clinical trials are listed separately.
Does PeptideCompare give dosing or medical advice?
No. Where amounts appear, they are what published studies or official labels used, with the source cited. Nothing on the site is a recommendation for personal use.
Using the site
Can I compare two peptides side by side?
Yes: 57 comparison pages put two compounds next to each other with price, vendors, research grade and status.
Can I submit a lab report or a price correction?
Yes. Submit a lab report or correction; submissions are reviewed before they appear.
Is there a community forum?
Yes, the PeptideCompare forum covers vendors, lab results and research discussion. Vendor connections must be disclosed and personal-use advice isn't allowed.