The stuff is branded ezricare, sold on Amazon, and made by a company called Global Pharma Healthcare Private Limited. Are they just companies I don't happen to

The stuff is branded ezricare, sold on Amazon, and made by a company called Global Pharma Healthcare Private Limited. Are they just companies I don't happen to know because I'm dumb, or anyone can just set up his lab to sell medicine on Amazon? How is the supply chain monitored for drugs ?