An online pharmacy is a website or virtual store where customers can purchase medications, supplements and other health-related products. These websites typically offer prescription drugs that require a valid prescription from a licensed physician before they can be dispensed by the pharmacy. They also sell over-the-counter (OTC) medicines which do not need a prescription to purchase. Online pharmacies may operate under different regulatory frameworks depending on their location, and customers are advised to ensure that they are purchasing from legitimate sources in order to avoid counterfeit or substandard products.