The main purpose of the Food and Drug Administration (FDA) is to protect public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices, as well as ensuring the safety of the nations food supply, cosmetics, and products that emit radiation. The FDA is also responsible for regulating the manufacturing, marketing, and distribution of tobacco products to protect public health and reduce tobacco use by minors. The FDAs responsibilities extend to the 50 United States, the District of Columbia, Puerto Rico, Guam, the Virgin Islands, American Samoa, and other U.S. territories and possessions.

The FDA plays a significant role in protecting public health from various threats, including pandemics and bioterrorism. The FDA regulates a wide range of products, including drugs, medical devices, tobacco products, cosmetics, food for pets and livestock, and dietary supplements. The FDA ensures that these products meet certain quality standards before they are introduced to the U.S. market. The FDA also coordinates with its counterparts in other countries to align standards on food safety.

In summary, the main purpose of the FDA is to protect public health by ensuring the safety, efficacy, and security of various products, including drugs, medical devices, and food, and by regulating the manufacturing, marketing, and distribution of tobacco products.