Why do some peptide sellers charge so much more for the same milligram amount?

A higher price per milligram sometimes just means a smaller vial. Price per milligram drops as vial size grows for nearly every compound this site tracks. It can also reflect testing and sourcing costs that a cheaper seller has not paid. On its own, a higher price is not proof of higher purity. Only a test report you can check with the lab tells you that. This site's price pages hold vial size the same so the comparison is fair.

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of buying, vendors, and lab testing. How to evaluate a seller's claims, certificates of analysis, and pricing.