@Nk9bjP4A Just like Western alchemy and it's search for the Philosopher's Stone, with it's resulting Water of Life that gives immortality, Eastern alchemy was also focused on achieving immortality.
The big difference between the two was that Western alchemy was all about chemical reactions and creating or changing matter, while Eastern alchemy was more like pharmacology. They used plants, herbs, and animal parts, with some "magical" elements like gold or mercury added in for extra "effects." Unlike Western alchemy, the end product of Eastern alchemy was considered medicine, and usually intended to be eaten, and was made into pills.
Ironically, much like Western alchemists' exposure to dangerous chemicals killed the alchemists (sometimes immediately and explosively, sometimes through chronic illness like lead poisoning), Eastern alchemy's obsession with the preservative powers of mercury and the way gold is (mostly) immune to tarnishing led to them consuming massive amounts of both, leading to either death or long-term illnesses.