Philip K. Dick/The Three Stigmata of Palmer Eldritch

The plot of this novel involves the use of a hallucinogenic substance called Chew-Z which is marketed with promises of eternal life. It is quickly out-doing its competitor, Can-D, which is used for entertainment by bored Martian colonists. However, the effects of Chew-Z are not at simple as eternal life or entertainment. The man who brought this amazing substance back from the Prox star system, Palmer Eldritch, may have ulterior motives involving the God-like powers that Chew-Z seems to grant him and total control of humanity.