7Up used to contain lithium.

Want to regulate your baby's mood swings? Nothing does it like Seven-Up!

In fact, the soda used to be named "Bib-Label Lithiated Lemon-Lime Soda"! This soon got shortened to "7Up Lithiated Lemon Soda," and then just "7Up" in 1936. But why is having lithium as an ingredient strange? Because lithium is used as one of the most common treatments for bipolar disorder!

Its creator, Charles Grigg, included the substance in the soda's formula because he thought it could be used as a selling point. He believed the naturally-occurring lithia found in underground springs that could be promoted as a mood regulator! If you're concerned about the content of the 7Up you're drinking these days, don't worry - lithium was removed from the soda over half a century ago.

Read more about 7Up, including theories about its name and the red dot logo. My favorite debunked theory is that the red dot logo is there to represent Charles Grigg's red eyes.