Answer: 7 Up
If you purchased a bottle of the original 7 Up formulation, you got a small dose of lithium citrate—not unlike the lithium used in psychiatric care to stabilize the mood of patients suffering from bipolar disorder, mania, or depression. Originally called, more transparently, “Bib-Label Lithiated Lemon-Lime Soda”, the inclusion of the lithium was considered a solid selling point for the brand—after all, who wouldn’t want a mood boost with every bottle?
Did the creator of 7 Up, Charles Leiper Grigg, set out with the goal of medicating people? In fact, the inclusion of lithium in his drink is a side effect of where he set up shop. Select locations around the world have springs with naturally occurring lithium-rich water, known as “lithia water”. When he discovered the lithium in the St. Louis water source he was drawing from, it was only natural to ensure that the public knew his product included the mood boosting drug and “Lithiated” was added to the name of the soda.
Bonus Trivia: Although there is no official origin story for the name “7 Up”, the current holding company claims that it refers to the original seven main ingredients. One of the apocryphal stories is that the 7 in the name was a nod to the atomic weight of Lithium (rounded to a whole number from 6.94).