I trust these people. That's the biggest reason. Aside from that everything on the market is weaker compared to the 80's and 90's versions, so take more. Bottom line is they deliver are private and fix problems if they should arise. When putting something into your body you want to minimize side effects and knowing your not getting sick, covid, hep, or God knows what should be reason enough. You do not want someone making it in some dudes bathtub or kitchen in China. This is made in real labs and often the same labs used for the real products but after hours by professionals. That's as good as your going to get unless your daddy owns a pharmacy or is an oncologist.