Hi Jared! You've always struck me as a fairly private person. Do you hate giving interviews? No, not at all. But if the interview's bad, then it's no fun, and by bad I mean routine, you know? So the challenge has been set!
When you were preparing to play Rayon in Dallas Buyers Club, an HIV-positive transgender woman, did you talk to trans people and people with HIV? Yeah, definitely. I talked to transgender people and that was the education and the start of it all. I'm really grateful for those experiences.
Did you go method? I stayed in character the entire shoot. I couldn't imagine doing it another way. I'd gone too far to pick it up and drop it off.
Is it true you turned down the role several times? Yes. I wasn't looking to make a film, I hadn't made one in years and I was beginning to think maybe I'd never make another one. But they were persistent and I thought the character was astounding.
Why did you think you weren't going to make another film? I hadn't even read any scripts so I don't know if there were any interesting ones around. I was busy and fulfilled with Thirty Seconds to Mars.
And now you have an Oscar (1)! Yes, although it's not about a trophy or accolades or me. It's about having a moment to stand in front of the world and acknowledge the people and things that mean so much.
You've manipulated your bodyshape for roles many times (2). Does that help you get into character? It certainly works for me to have a physical commitment. I enjoy the challenge of a physical role.
How much weight did you have to lose for this role? I lost around 40lb [almost three stone/18kg] and then I stopped counting. For me, it was about how it made me feel, how it made other people treat me. I got down to something like 114lb [about eight stone], and that was enough to do what I wanted it to do, which was to change everything about me.
How did it make other people treat you?
It provides you with a certain amount of fragility, it changes the way you walk and talk and think and move. It changes you inside and out.
Did you and Matthew McConaughey talk about you both losing so much weight for the film? No, I only communicated with other people as Rayon, so I wasn't talking about things like that with anyone.
Your film CV is pretty extraordinary: Requiem for a Dream, American Psycho, Panic Room. Does a movie have to be very intense in order to lure you away from your music career? Yeah, I would say so. I have never been in a hurry to make a film just to work. I want to be part of things that are meaningful and rewarding.
Were you more interested in music or film as a teenager? I was more interested in art – I'm an art school dropout. But really, I just wanted to be a creative person who could make things, and that hasn't changed.
So you never practised your Oscar acceptance speech in front of the mirror as a kid? Oh no, no, no. As a kid I wasn't even watching television, I was surrounded by hippies in a tepee in a commune in the middle of the forest. We certainly weren't thinking of awards shows. I've never pined for awards.
You had a turbulent time growing up and you said once that the point when you started to turn your life around "involved a gun and some cocaine". What was that about? I think I was trying to say how there are those moments that affect your life rather than getting into the details surrounding it that may sound sensational. I think we all have moments in our lives when we have epiphanies that force us to act and propel us in directions.
Your first big role was as Jordan Catalano in My So-Called Life (3). Was it strange to play a teenager who had such a different experience growing up? No, it was fine – I felt that was just what acting was so it was interesting.
How often do thirtysomething women come up to you and ask about Catalano these days? People come up and ask about 30 Seconds to Mars these days – that's the most common, and now it's Dallas Buyers Club, too. I think in the airport today I've taken 40 or 50 photos with people because now everyone has a camera on their cellphone.
Thirty Seconds to Mars has had some high-profile battles with the record industry. Are you done with all that now? Well, it's a process. A few years ago we discovered that, despite having sold millions of records, not only were we not going to get paid a penny [by our record company], but we were millions and millions of dollars in debt (4). So we discovered there was a law in the state of California, the seven-year statute, which is actually called the De Havilland Law (5).
Did you talk to Olivia de Havilland about your problems? Yes, I ended up meeting with her in Paris, and we had a wonderful time together and I thanked her for fighting the studios back then so I could fight them now. It was amazing to meet her – she's, like, 98 now and is a legend. We made a movie about our battles, called Artifact, which we just released on iTunes.
So what's the situation now with the record companies? It's ongoing – progress, not perfection.
But are you guys making any money now? Uhh ... it's a never-ending battle.
(1) Leto won his Oscar for best supporting actor at this year's ceremony.
(2) Leto lost two stone (12.7kg) to play a heroin addict in Requiem for a Dream, and then put on about five stone to play Mark Chapman in Chapter 27.
(3) Jordan Catalano could lean more sexily than anyone on TV ever. Fact.
(4) Virgin Records tried to sue the band for $30m (£18m) for failing to make three of the five albums they promised to deliver in a 1999 contract.
(5) Named after the actress Olivia de Havilland, best known for playing Melanie in Gone with the Wind and a whole slew of Errol Flynn films, who fought the studio system in 1943.
• Jared Leto: 'I road-tested my character to get a little judgment, some meanness, a little condemnation'