How Do EpiPens Work?

The price of EpiPens has increased more than 400 percent since 2007. People who need to keep them on hand — often because they may need the emergency drug in case they have a life-threatening allergic reaction — brought the price increase to light, and eventually it reached Congress: In a letter to Mylan, the company that makes EpiPens, Sen. Charles Grassley of Iowa has now asked the company to explain its pricing. But how do EpiPens work?