In the U.S., the government's Food and Drug Administration (FDA) must approve any drug - whether it's prescription or over-the-counter - before it can be sold. The FDA evaluates the safety of a drug by looking at side effects, how it's manufactured, results of animal testing and clinical trials, and more. The FDA also monitors a drug's safety after approval. To make sure you use drugs safely Make sure that you understand and follow the instructions on taking the drug Don't share medicines Let your health care provider know about all other drugs, supplements and herbs you are taking