For those paying attention, there has been a distinct, can't-miss shift in Matthew McConaughey's film career over the last several years. In character-driven, often challenging indie pictures such as 2012's "Bernie," 2012's "Magic Mike," and 2013's "Mud," the good-looking, laid-back, "hey, hey, hey" performer who had become better known for taking his shirt off in romantic comedies than for his acting prowess has clearly begun choosing projects for art over commerce. His work in "Dallas Buyers Club," based on the 1980s-set true story of AIDS-afflicted electrician-turned-activist Ron Woodroof, is physically and emotionally transformative, one more concrete reminder of the range he once seemed to have before lesser scripts within the Hollywood studio system got in the way.

In 1985, Ron Woodroof is the living embodiment of a white-trash stereotype: he's a womanizer, a chain-smoker, a recreational drug-user and an ignorant homophobe. Beset with worrisome ailments—blurred vision, light-headedness, a nasty cough—it is an accidental electrocution while working on a fuse box that sends him to the hospital and, consequently, to the devastating news that he is HIV-positive and has only thirty days to live. Ron's immediate reaction is anger, and then denial. When that subsides, he turns to research, his frustration with the ineffective FDA-approved meds and procedures leading him to seek experimental treatment in Mexico. Threatened with criminal charges if he illegally sells the anti-viral pills for profit, Ron finds a loophole wherein he provides the alternative drugs to customers who have paid to sign up for membership. In his pursuit to live another day, he ultimately defies his doctor's grim prognosis as his buyers club, like many popping up across the country, prompts the outraged FDA and pharmaceutical companies to take the matter to court.

Directed by Jean-Marc Vallée (2009's "The Young Victoria") and written by Craig Borten and Melisa Wallack, "Dallas Buyers Club" is a tough rendering of a sensitive real-life story. Despite the occasional unpolished scene transition and a small handful of convenient plot conventions, no doubt used to condense the story and clarify its themes, this is a compelling drama that never sugarcoats its prickly, short-tempered lead character or his brave yet despairing struggles. Ron begins the film as a vehemently intolerant man whose travails open his eyes to the diversity in the world around him. It is a slow but sure process, and treated with a rawness that avoids overt vilification even as it refuses to soft-pedal his prejudices and initial lack of education. Helping Ron to let go of his hateful belief system is fellow AIDS sufferer and eventual business partner Rayon (Jared Leto), a caring but deeply troubled transgender male.

Matthew McConaughey shed fifty pounds to play Ron Woodroof, and it is an alarming metamorphosis to rival that of Christian Bale in 2004's "The Machinist." His physical commitment gives depth and realism to the part, but it is McConaughey's riveting internal grasp of his character and the plight he faces that makes his work here unforgettable. Matching him throughout is a phenomenal Jared Leto (2005's "Lord of War"), entirely unrecognizable as Rayon, a man of both limitless compassion and a hidden self-loathing he refuses to reveal. Both actors handle shattering dramatic moments with an absence of artifice and histrionics. Also excellent, but with a far less showy role, is Jennifer Garner (2012's "The Odd Life of Timothy Green") as the passionate, kindhearted Dr. Eve Saks.

"Dallas Buyers Club" is a moving, always mature account of a personal story that warrants attention. Breathing crucial vitality into a fallible figure withering away even as he regains his dignity, McConaughey has scarcely, if ever, been better. In an era when HIV and AIDS were still in their infancy and, in no uncertain terms, a death sentence, Ron Woodroof fought to turn things around for himself and his disease. Before he died, he wanted his life to mean something. It did.