"Many of us can barely make it through the morning without first downing a cup of hot coffee. It's become such a big part of our daily rituals that few actually give much thought to what it is that we're putting in our bodies."

"To help us break down the little-known things about caffeine, NPR's David Greene spoke with Murray Carpenter, author of Caffeinated: How Our Daily Habit Helps, Hurts and Hooks Us. These are the things you probably aren't thinking about as you wait in line at your local coffee shop."

"In its essential form, caffeine is a bitter white powder derived from a natural insecticide found in some plants. Over the years, it became acknowledged as a drug after people independently discovered its stimulating effect."