EXPLAINER: Why is insulin so expensive and difficult to cap?

Insulin is displayed at Pucci's Pharmacy in Sacramento, Calif., July 8, 2022. Senate Majority Leader Chuck Schumer, D-N.Y. said this week that Democrats planned to add language to the economic package focused on climate and health care that will be aimed at reducing patients' costs of insulin, the diabetes drug that can cost hundreds of dollars monthly. (AP Photo/Rich Pedroncelli, File)

WASHINGTON (AP) - Reining in the soaring prices of insulin has thus far been elusive in Congress, although Democrats say they'll try again - as part of their economic package that focuses on health and climate.

The price of the 100-year-old drug has more than tripled in the last two decades, forcing the nation's diabetics to pay thousands of dollars a year for the life-saving medication. Democrats are considering capping the cost of that drug for at least some, although it's unclear what the final proposal will look like and how many insulin users will get a price break.

Here's a look at how insulin became so expensive and why it's so difficult to bring the price of the drug down.

HOW MANY PEOPLE IN THE U.S. USE INSULIN AND FOR WHAT?

Roughly 8.4