The plot of "Dallas Buyers Club" follows Ron Woodroof's journey from a 30-day death sentence to surviving for seven years. A key turn occurs when Ron realizes the FDA-approved drug AZT, which he initially bribes a hospital worker to obtain, is actually making him sicker due to its high toxicity in trial doses. This discovery fuels his search for alternative treatments in Mexico, where he meets a disgraced doctor who prescribes a cocktail of unapproved vitamins, proteins, and drugs like ddC and Peptide T.
The central plot device is the formation of the club itself: to circumvent laws against selling unapproved drugs, Ron sells memberships for $400 a month, and the drugs are then dispensed for free. This clever loophole allows his operation to flourish. Ron's character arc is inextricably linked to Rayon. His initial revulsion gives way to a grudging business partnership and then a deep, genuine friendship. The emotional climax of his transformation happens when he forces his old friend T.J. to shake Rayon's hand after T.J. insults her.
A major tragic turning point is Rayon's death. Having relapsed into drug use and sold her life insurance policy for the club's benefit, she is hospitalized and eventually dies. Her death deeply affects Ron, erasing any last vestiges of his former prejudice and steeling his resolve to continue the fight. In the film's final act, Ron sues the FDA for the right to use Peptide T. He loses the case, but the judge admonishes the FDA, acknowledging the moral righteousness of Ron's cause. The film ends with a title card explaining that Ron died of AIDS in 1992, seven years after he was predicted to live for only 30 days.