The McConaissance goes from strength to strength in this moving period drama that breaks free of its Oscar-grabbing shackles thanks to a pair of magnetic performances.

The dark days of Failure To Launch and other dire rom-coms that demanded he lean next to someone on the poster are thankfully an increasingly distant chapter in the career of Matthew McConaughey.

In the past couple of years, McConaughey has finally fulfilled the early promise he showed in the likes of Dazed And Confused (“well alright, alright, alright”) and Lone Star and in that relatively short time has become one of the most exciting screen actors working today.

Hot on the heels of his memorable cameo in The Wolf Of Wall Street, McConaughey switches gears to play Ron Woodroof, the hard-living redneck electrician and rodeo cowboy whose world collapses from under his feet when he learns he is HIV-positive and in all likelihood will be dead in a month.

Set in 1985, myth and conjecture were still rife when it came to the growing Aids epidemic, not least of all in the mind of the homophobic Ron who, like many people at the time, thought it was a disease restricted to homosexuals. Shunned by friends and family and denied access to what Government-approved antivirals there were at the time, Ron takes matters into his own hands and seeks out whatever drugs he can find that might prolong his life.

Realising there are many more like him out there, he goes into business with Rayon (Jared Leto), a HIV-positive transgender woman who has the necessary contacts to facilitate the set-up of the Dallas Buyers Club wherein ‘members’ pay a month fee for unapproved medication. As business booms it attracts the unwanted attention of the Food and Drug Administration (FDA), which threatens legal action.

Much has been made of the weight both McConaughey (50 lbs) and Leto (30 lbs) lost for their roles and it’s admittedly startling at first to see just how emaciated each actor looks, McConaughey in particular. However, this dramatic weight loss should not distract from what are two of the most committed and honest performances you’ll see all year.

These are golden days for McConaughey and the actor disappears into the role to deliver his most complete performance to date. Ron’s journey from free-wheeling homophobic redneck to compassionate social campaigner never once feels false or ham-fisted and the actor maintains the character’s charm, humour and stubbornness even during his darkest moments.

In his first role for six years, Leto is a revelation. Male actors dressing up as women has largely been used as a tool for comedy in the past, but Leto finds a similar conviction and voraciousness to the remarkable performance given by Jaye Davidson in The Crying Game.

Likewise, Jennifer Garner does well in the tough role of Dr Eve Saks, who forms a bond with Ron and starts to question whether what she and her supervisor Dr Sevard (Dennis O’Hare) are doing to ‘help’ Aids sufferers is actually making a positive difference.

Where the film does fall down is in the black and white way it portrays the conflict between Ron on one side and the FDA and American health care system on the other.

Director Jean-Marc Vallée appears to ask Michael O’Neill’s FDA official Richard Barkley to just look angry and menacing the whole time, while O’Hare’s Dr Sevard is little more than a cipher to show how cuddly the health care system and big pharma are.

While the relationship Ron strikes up with Eve is sweetly affecting, it’s his bond with Rayon that’s Dallas Buyers Club‘s beating heart. The moment when Ron instinctively defends Rayon against a former buddy who’s ostracised him comes as much as a surprise to us as it does to the two of them. It’s a beautifully played moment that signals a turning point in their relationship from business associates to friends.

To the film’s credit it never wallows in grief or cynically pulls the heartstrings; what we get instead is a forthright and rousing tale of dogged determination in the face of death lifted by a pair of remarkably raw performances.