As soon as I walk into her suite at London’s Soho hotel, Shailene Woodley bounds over and gives me a warm hug with a back-pat finisher. This is her thing – a courtesy extended to colleagues and sometimes journalists and fans – something she has said helps “to cut the bullshit” when she meets a new person. And hugging is really one of the lesser eccentricities of the 23-year-old American actress; others include brushing her teeth with clay, making her own deodorant and fixing home-made medicines when she’s under the weather. Unforgettably, she once commented that she likes to sunbathe naked to “give my vagina a little vitamin D”.

Hippy soundbites like that could overshadow the day job, but Woodley is doing just fine, curating a smart mix of lucrative blockbusters and attitudinal independents. Born in the suburbs of Los Angeles, she has acted since she was five, mostly in commercials and on US TV. Her movie break in 2011 came when Alexander Payne cast her in 2011’s The Descendants as George Clooney’s grumpy daughter. There hasn’t been a misstep since. Last year, Woodley starred in the adaptation of John Green’s Young Adult blockbuster The Fault in Our Stars. She is currently appearing on British screens in the art-house White Bird in a Blizzard and the every-house, second instalment of the four-part The Divergent Series franchise, Insurgent. The first, Divergent, released last year, introduced Woodley as Tris, the feisty warrior-heroine at the heart of the story, and made nearly £200m, which is moving towards Hunger Games territory.

Woodley takes a seat on the sofa, curls her feet underneath her, like a cat. She wears a chunky Nordic sweater, black leggings and socks; no shoes or any obvious make-up. The pressures of promoting two new films globally are starting to take their toll, so she drinks a herbal blend of echinacea, goldenseal and St John’s wort to keep her immune system ticking over.

Shailene Woodley as Tris in The Divergent Series: Insurgent: ‘I definitely had my doubts, but having said yes, I wouldn’t change it for the world.’ Photograph: Allstar/Summit Entertainment

So you make all your own medicines then?

Yeah, in a way of sorts, absolutely. I’m a fan of western medicine as well, because if you have something that could be life-threatening, antibiotics save lives every day. But the thing with medicine nowadays is there’s this lack of understanding of our bodies on a deep personal level. If you have a headache or insomnia, it’s so much easier to take a pill for that than to deal with the core problem, which could be a very simple fix.

When was the last time you popped a couple of headache pills?

Oh, I haven’t taken Advil since I was a kid. It’s probably been close to 10 years.

What’s the secret to your toothpaste?

It depends on your needs. I like to have clay in there, because it helps detoxify or rid our bodies of heavy metals and radioactive isotopes. It just feels good for my body. Also, I think it’s part of our responsibility to ensure our descendants have water to drink and food to eat from soil that’s been preserved by our caretaking.

Is it true you originally said no to the part of Tris in the Divergent films?

I did. I was a little trepidatious saying yes to a franchise, simply because I’d just come off a television show [The Secret Life of the American Teenager] where I had a six-year contract. So the thought of signing another four-year contract was quite daunting. Also I had said, growing up as a child actor, that I’d never be a part of a big studio franchise, because I never wanted that sort of recognition around the globe. I liked doing smaller roles and I really just love acting because I like being on a movie set and that’s it. So I definitely had my doubts, but having said yes, I wouldn’t change it for the world.

Was there something that made you change your mind?

I asked advice from a lot of people I respected and ultimately my mom said, “Well, Shai, you’re about to say no to this opportunity because of the budget on the film. If this was an independent film, would you say yes?” And I thought I would say yes, because I love Tris and I do love the storyline and the themes involved within this particular book.

Didn’t Jennifer Lawrence tell you, “There are some things – don’t make a sex tape, don’t do drugs, don’t do things in public – that you wouldn’t want other people judging you for. But this is the best decision you’ll ever make”?

She was definitely one of the people who gave me some great advice, but I asked lots of different people.

There’s a scene in Insurgent where you appear to do a flying tackle on Kate Winslet. Did that really happen or was it realistic special effects?

Yeah, I took her out. Actually, that’s a very interesting shot. That was my stunt double as well as Kate’s stunt double, because insurance wouldn’t let us do it. Those bodies you see are not mine and Kate’s bodies, but they took their faces off and put our faces on. So, there was no harm done to either of us, although we were both game to do it.

Did you get bashed up in the shoot at all?

You do a little bit. There weren’t any injuries on this movie, but you always want to push it, or at least I always want to push it. Why not? Stunts guarantee safety in a certain manner and you get to have an adrenalised thrill ride without the repercussions of getting hurt. You can get bumped or bruised, but the worst that would happen would be you’d break something. There’s no life-or-death situations.

Insurgent and White Bird in a Blizzard are very different in scale, themes and budget. Is that how you want your career to be?

As an actor you get to try all sorts of different hats on and share hats and own hats and rent hats and give them back. And have them taken from you. And I think that’s wonderful.

Are you still able to travel around staying in Airbnb apartments?

Absolutely. I did a trip right after we finished filming Insurgent in Europe, around Spain and Italy, visiting friends and what not.

So the fears you had before signing up for the Divergent films haven’t materialised?

The fear was loss of anonymity in a way, but I really haven’t lost much of my anonymity. I can still live the life I’ve been living. I’m busier, but I would love to continue exploring and living this nomadic lifestyle.

Shailene Woodley as Kat Connor in White Bird in a Blizzard, with Christopher Meloni as her downtrodden dad, Brock. Photograph: Magnolia Pictures/Sportsphoto Ltd/Allstar

You didn’t have a mobile phone for almost a year – didn’t you worry that might affect your career somehow?

I didn’t have a cellphone after I filmed Divergent. I just realised that a phone wasn’t necessary in my life at that time, so I didn’t have one for a bit. I feel like we place too much importance on ourselves and on people needing to get hold of us. There is a responsibility that you have no matter what job you do to show up for people and to not let people down. But the ways you get from A to B can all be different and varying.

After The Descendants, you didn’t work much for a couple of years – were you not advised to capitalise on the success of that film?

I didn’t work because I didn’t read anything I particularly loved. The one script I did read and was passionate about was called The Spectacular Now and that movie took a year and a half to get made. And I’m in the same position right now. I haven’t read a script that I feel particularly moved by or drawn to. It might be five years until I do another film. A lot of people in this industry work just to simply work, or you’re on a wave so you must ride it. But if you look at it from a place of passion and you go: “Well, if this is meant to be art and if this is something my soul is getting something out of or my right brain is being stimulated by, why would I work to work?” Because then the title goes from being an artist to being a workaholic in a sense.

That’s very self-assured...

I have the luxury of having been an actor since I was five. So I know that nothing comes overnight and I know that you have to work really hard in order to be successful. I know if I don’t work for five or six years, maybe it will be harder to get a film, but if I’m not booking films, I will bust my ass at acting classes because if it’s something I’m still that passionate about, then why wouldn’t I want to continue to improve my craft? But if I’m being hired simply because my name is a name, that doesn’t feel good. That’s like somebody buying your painting simply because of how much they’re told it’s worth, versus actually enjoying looking at that painting and feeling inspired by it.

At the end of the year, we’ll see you in Oliver Stone’s Edward Snowden biopic. That’s likely to be a controversial film – did you have any hesitation signing up for it?

No hesitation whatsoever. It was something I felt was worth fighting for. What I find so compelling about the Snowden situation is that he’s very much in a place where we don’t know what’s going to happen. Will he ever go back to America? Will he stay in Russia? What happens when his asylum ends? There are so many open-ended questions. And being a woman, a young woman in the world today, I am grateful that I have access to information from the files that Edward decided to leak.

Has your view of Snowden changed?

No, it hasn’t changed at all. Listen, people are quick to say he’s a hero or he’s not a hero. I learned my lesson when I did an interview a few days ago and they changed what I had to say and now the headlines are all over the place. But let’s just say that I’m so glad the information he leaked is out there. I feel empowered by it, my life changed because of it, way before this movie was even around. Now, to be a part of this movie is exciting because even though a lot of people know of Edward Snowden, a lot of people don’t know a lot of the facts he released.

In the film you play Snowden’s dancer girlfriend Lindsay Mills and part of the preparation has been learning to pole dance. For Divergent you trained in knife-throwing. Are you picking up some useful life skills?

I am learning really useful life skills, actually. I’m not being facetious. It’s part of the beauty of being an actor.

Even pole dancing?

It’s athleticism.

White Bird in a Blizzard is out now; The Divergent Series: Insurgent is out on Friday