Dakota Johnson: My periods are ruining my life'

Fifty Shades Freed star Dakota Johnson is struggling with her monthly menstrual cycle and the way it affects her body.

In a candid new chat with InStyle magazine, the actress reveals hormonal changes during her period are "ruining" her life.

"It’s unbelievable, it's really f**king amazing," she tells the publication. "I can’t get a grip on it. I’m like, 'What?'

"Every time, I’m totally scandalised about what happens to my body and my brain. My boobs are like eight times the size they normally are. It's really a traumatic thing, and it happens every month. I just can’t get used to it.

"It’s kind of miraculous how much your body can switch and change. You're like, 'What’s wrong with me?' And then you realise. It's insane."

And the changes have made her question the pills she is putting in her body to prevent an unplanned pregnancy, adding, "It’s very tricky to figure out what type of birth control you’re meant to be on, and if it’s even healthy... I really would like to understand and be able to manage things a little better, know what’s happening in my body, and know what I’m putting into it."

The star is getting plenty of information as an advocate for her boyfriend Chris Martin's Global Citizen charity, studying up on reproductive education and "What it means to have a woman body, and how do you honour it the right way? How do you not jam chemicals into your brain in order to feel good?"

"It’s a remarkable thing," she adds.