* Sara Goldfarb (Ellen Burstyn): A widowed, aging woman who becomes addicted to diet pills in her pursuit of a slimmer figure.
* Harry Goldfarb (Jared Leto): Sara's son, who dreams of opening a clothing boutique but becomes addicted to heroin along with his friend, Tyrone.
* Tyrone (Marlon Wayans): Harry's best friend, who also becomes addicted to heroin and dreams of being a drug dealer.
* Marion Silver (Jennifer Connelly): Harry's girlfriend, who struggles with heroin addiction and dreams of becoming a model.
Each character's journey is intertwined, and their individual struggles with addiction and the pursuit of their dreams contribute to the overall narrative.
While there isn't one central protagonist, Sara Goldfarb is often considered the most central character due to the film's focus on her descent into addiction and its devastating impact on her life.