About FDA

What are the possible side effects of a drug and where can I find the most current information about my drug?

All drugs, whether prescription or over-the-counter, can have side effects. Side effects can range from headaches and upset stomach to those more serious such as liver or kidney injury, heart problems, or even death. Some side effects can be predicted in some people based on what occurred during the drug’s testing, but some rare events occur unexpectedly when many more people take the drug after it is approved.

The best way to know the possible side effects from a drug is to read the drug label. The label is the most complete single source of information on the drug. The label for most FDA-approved prescription drugs, including the full prescribing information (package insert), can be found at

  • FDA’s Web page Drugs@FDA
  • the Web site DailyMed, which is provided by the National Library of Medicine as a public service and does not accept advertisements.

For OTC drugs, side effects are included in the “Drug Facts” printed on the outer wrapper or container of the drug.

Page Last Updated: 09/23/2017
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