7up's odd history

7up used to contain lithium citrate, which was even at the time known to be a mood stabiliser. Only 28 years later was lithium removed from the formula, due to some not so pleasant side effects.

Nowadays lithium is still the primary medication for bipolar disorder, acting on the central nervous system.

The pathway (which scientists currently believe) that lithium uses in the body is fascinating, displacing magnesium ions to inhibit regular bodily enzymatic pathways.