Janie effectively gives Phoeby (and therefore the rest of the town) "the elixir" at the end of the novel by sharing her story about empowerment and love, two things which she found in the course of her Hero Journey. When Janie finishes, Phoeby exclaims, "Lawd! Ah done growed ten feet higher from jus' listenin' tuh you, Janie. Ah ain't satisfied wid mahself no mo'" (192).
Janie introduced new ideas to Phoeby about what real love should be like, and marriage for that matter, and her experiences help Phoeby see that she can have more in life. . . which is the goal of the Return with the Elixir, the final stage in the Hero Journey.
I thought this novel really fit perfectly with the Hero Journey, and the completion of the final stage is no exception.