Lithium in 7UP
“The original formulation contained lithium citrate, which was used in various patent medicines at the times for improving moods. It has been used for many decades to treat manic-depression. It was popular to go to lithium-containing springs such as Lithia Springs, Georgia or Ashland, Oregon for this effect.
Lithium is one of the elements with an atomic number of seven, which some have proposed as a theory for why 7UP has its name. Grigg never explained the name, but he did promote 7UP as having effects on mood. Because it debuted at the time of the stock market crash of 1929 and the onset of the Great Depression, this was a selling point.
The reference to lithia remained in the name until 1936. Lithium citrate was removed from 7UP in 1948 when the government banned its use in soft drinks.”
– source – https://www.thoughtco.com/history-of-7up-charles-leiper-grigg-4075324