SF. Philip K. Dick's "The Three Stigmata of Palmer Eldritch", as description

When the mysterious Palmer Eldritch returned from a distant galaxy, he claimed to have brought a gift for mankind.  Chew-Z was a drug capable of transporting people into an illusory world, a world they could linger in for years without losing a second of Earth time.   For the lonely colonists living out their dreary term on Mars, here was the ultimate trip, a pastime that could deliver immortality, wish fulfillment - the twin-power over time and space.   But, in return, Palmer Eldritch exacted a terrible price.  He would enter, control and ge god in everyone's private universe, a universe from which there was no escape, not even death.

A Panther 1978 paperback in good/very good condition based on the Hancer Standard.