If it wasn't challenging enough to play an infertile wife, who has to appear on camera watching the ritualised rape of young women by her rich husband in order to bear children for her, imagine doing that while wondering about your own fertility. The best actors in the world would struggle – Ella Wright included.

The 37-year-old Emmy and Golden Globe-nominated actress, who plays the menacing Serena Joy in the extraordinary The Handmaid's Tale series – barren wife of Fred (Joseph Fiennes) and mistress of Handmaid Offred (Emmy-winner Elisabeth Moss) – shares that the latest season in particular has led her to evaluate the pursuit of her own family as a single woman. "I think it's my responsibility as a woman in my late thirties to be honest that it's hard for me, and that I wrestle with it daily, especially when fertile bodies are as much of a political battleground as they've ever been," the American star tells GLAMOUR exclusively.

"We're still living in a world where people think it's always okay to ask women or couples about their family planning, meaning well but unaware of the warzone it can be personally or within a relationship," she says. "And I'm really proud that our show doesn't shy away from how different women – and men – handle fertility and growing their families, and that something that should be joyous can also be emotionally gruesome."

Perhaps it shouldn't be surprising, though, that a show with so much power over its audience should have such an effect on one of its own stars. The Handmaid's Tale is one of the darkest, most gripping and genuinely society-altering shows of the past decade, pushing its actors into often unexplored territory and inspiring an unprecedented uprising of real-life activism among its devotees.

Based on the novel of the same name by the Booker Prize-winning and global bestselling author Margaret Atwood, the story is set (just like the novel), in a near-future society where a radical political group has overthrown the US government to create Gilead. In this new state, all women and minorities have been subjugated, and because environmental pollution has caused large-scale infertility, the fertile women left have been abducted and turned into Handmaids. They are then sent to the homes of rich commanders who ritually rape them once a month, in order for them to bear children for their wives.

The show is in turns desperately heartbreaking, brutal, rage-inducing and disturbing. But, also, utterly compelling and – set against the backdrop of #MeToo, Trump's presidency and the ongoing battle for women's rights globally (the number of US states imposing new and restrictive laws on abortion, and even in the UK, the near total ban on it in Northern Ireland) – uncomfortably prescient. It's sometimes hard to believe that Atwood's original novel was written in 1984. This September, 35 years on, she's releasing a sequel, The Testaments, which is likely to be just as searing a takedown of society – present and future.

Wright herself says she feels privileged, despite whatever personal psychological challenges it presents, to be part of such a seminal show. "It takes my breath away how moved people are by it. They're enraged and they're disgusted but they're also incredibly effusive in their love of the show. It's been powerful for so many – myself included, so I get it. And that kind of impact is rare."

The runaway success of Handmaid's and its increasingly vital contribution to the global women's rights debate is "like capturing lightning in a bottle" according to Wright, but it's not her first brush with the television zeitgeist. 15 years ago this autumn, a then-22-year-old Wright crash landed into Hollywood as part of the cast of ABC's runaway castaway hit Lost, launching her to stardom faster than you can say "Freckles."

And she's exceptionally upfront about how difficult that was. "I went from college in New York City directly to Oahu, and then the show took off," she says. "Within months, everyone on the island knew who we were, people were trying to sneak onto the beach where we filmed. I couldn't go home to LA without people stopping me in the airport and asking 'Jack or Sawyer?' or who kidnapped Claire or where the polar bear came from. Magazines wanted pictures of me in lingerie as the sexy castaway, photographers were hanging out on the beach where I'd go surfing or running, waiting to get pictures of me in a bikini.

"And yet the hardest part was that while we had this overwhelming success, I was being told by agents that I better hope I could ride this ride for a good long time, because I was a 'TV actress' now, and that was all people would see me as. You hoped and prayed for renewals, or that if you were canceled you could snap up something quickly. I was terrified by the celebrity side of it, and felt like I couldn't enjoy the success from which it came."

Little to Ella's knowledge at the time, Lost was riding the crest of a wave into a new era of television. After the third season finale, the network announced that the program would end after a further three seasons of only 16 episodes each, previously unheard of for successful broadcast series regularly clocking in at full 22-episode season orders. Impacted by the 2007 writers strike, the show's fourth season was further abridged to only 14 episodes. "We were all mentally preparing for this doomsday scenario of getting canceled, and then the network and showrunners made this incredibly gutsy call, to give us a final, definitive renewal.

"It was really freeing, and we all felt it," she admits. "We were moving towards something. It hadn't really been done before, this trust in the creative team with a finite amount of episodes over a finite number of years. But it worked."

When I ask Ella if she was pleased to know the end was nigh, or whether it felt like (to borrow her earlier language) a doomsday clock, she pauses for the first time. "I can't imagine it having gone any other way," she says. "You don't want to check out too early, you don't want to get senioritis. So yes, it was a relief to know we were never going to be waiting with bated breath for a renewal again, but I don't think it changed that it was f***ing hard to transition out of in the end.

"But in hindsight, we were setting this new precedent," she continues. "This gambit of self-determination was new for non-premium shows. And it wasn't just thanks to Lost, it was a bigger paradigm-shift, of finding this trusting way for shows not to overstay their welcome, and we were in the thick of it. Now showrunners aren't afraid to go to the networks with a finite plan, and the networks aren't as unwilling to gamble on shows with expiration dates. 'Limited series' would've been a dirty word fifteen years ago, now it's catnip."

Lost went off the air in 2010, and when Ella returned to the small screen four years later, streaming and binge-watching had taken over, and it was the era of Peak TV. Not everything had changed; she was once again working with Lost showrunner Damon Lindelof on a vaguely supernatural character drama (The Leftovers), this time for HBO.

"I only said yes because I knew this was a complete departure, pun intended, from how we'd done it the first time," she says, with a nod to the show's central mystery, the "Sudden Departure", a global event that resulted in 2% of the world's population disappearing. "They reinvested in us after the first season precisely because Damon had an end point in mind, not in spite of it."

The show received average ratings during its three-season run, but has since enjoyed a cult following, with many lauding the series finale as one of the best ever (a sharp contrast to the lukewarm-to-angry reception received by the ending of Lost). For her role as the grieving Nora Durst, who lost her husband and children in the Sudden Departure, Ella enjoyed high critical praise, including a Critics Choice Award for the show's second season.

"The attention is nice," she admits, "but what it means for me is that doors open up." Contrary to those early warnings from agents (she's since acquired new representation), Ella has enjoyed a successful film career interspersed with her work in episodic television. She's worked with the likes of Sir Ridley Scott, Kathryn Bigelow, and Danny Boyle, and has even served on the competition jury for the Cannes Film Festival. "We're now in an era where the membrane between film and television isn't as selective. You have wonderful filmmakers making television, and television creatives pitching feature-length scripts and not being laughed out of the room. It's not perfect, but it's a much more big-tent industry than when I started."

Ella suggests that a program like The Handmaid's Tale couldn't have been made a decade ago (it airs on streaming giant Hulu, and was their first big original hit), but when it did get made, nobody could have predicted the mix of positive reception and cultural impact it would ultimately have.

"We were on set the day after the [2016] election," she shares, "and it was like the show had changed overnight – quite literally." These days, it's not uncommon to see protestors donning the red robes and white bonnets of the show's titular Handmaids. "I have mixed feelings about it, personally, but I'm floored and inspired by the fact that so many people feel moved to action by the show. I feel a bit sick when I think about its relevancy, but I also know what a responsibility it is, to be making a show like this in this political moment."

She says that she and Ms Moss spend almost all their time together on set, in and out of character. But often, rather than larking about, they're constantly "discussing the script and what we're trying to achieve with each episode." Ella adds: "We have this incredible opportunity through the relationship [between Serena and Offred] to explore how women relate to one another, and to take a deep dive into this incredibly fraught dynamic. They can't bullshit each other, not after what they've seen of each other. It's incendiary and ice cold all at once, and I really enjoy sharing that with Lizzie."

But how does she – and the rest of the cast and crew – switch off? "I practice yoga, and I try to leave Serena off of my mat. But we also all have a lot of fun together. Someone or other will bring a guitar if we have an all-nighter, we'll do singalongs between set-ups. We dance a lot, jam to Maiye Grace, she's the fan favorite."

Ella's candidness about her work is refreshingly enthusiastic and non-Hollywood, maybe a far cry from what could be expected with her pedigree. Her father is Academy Award-winning director and producer John Wright, and her mother, Leah, is a luxury real estate agent. Ella grew up in the tony Los Angeles neighborhood of Brentwood, and attended the equally ritzy private school Harvard-Westlake (she was one year behind fellow actress and Hollywood scion Janis Jeffries). She has a degree in acting from the famed Juilliard School. "My parents never put pressure on me to do anything in LA in 'the industry,' and the irony is that I did go into the industry, I just did it in New York and Hawaii."

She now lives in a small-by-Hollywood-standards townhouse in Brooklyn's Boerum Hill, and surrounds herself with a selective and eclectic group of industry friends including Ms Jeffries, Juilliard classmate Oscar Isaac, directors Jon Favreau and Greg Newman, and former boss Mr Lindelof and his wife, Heidi.

Shortly after we conducted our phone interview in mid-May, Ella penned a moving public eulogy to her maternal grandmother, a Holocaust survivor who immigrated to the United States from Poland. While she has since not conducted new interviews for this season of The Handmaid's Tale, she shared with me in a follow-up email, "It's forced me to be more reflective. Life is precious, time is precious. I come from a line of women who didn't allow the shitty things in the world to stop them, and if I'm grateful for anything in playing Serena, now more than ever, it's that I get to be a part of the conversation about how we treat women, how we treat their bodies, and how we treat each other."

Our original conversation had, of course, turned to activism (although she doesn't don Handmaid garb to take part). "I've had a really hard time feeling like I'm doing enough, and like I'm helping rather than hindering," she admits. "I try to stay informed, because information is power. But words without action are just words. I try to put my money and time where my mouth is, even if I feel like it's a drop in the ocean and isn't doing much."

Ella was one of many famous faces and activists at the Women's March on Washington in January 2017, also participating in a Women's Day rally in Warsaw, Poland, that March, and was an early advocate for and supporter of the Time's Up movement late that year. She executive produced and narrated the documentary I Am Jane Doe, chronicling stories of child sex trafficking in the United States.

"I don't ascribe to 'stay in your lane' as such," she says. "I'm a woman, I'm an American, I'm the granddaughter of immigrants. These are my lanes. Am I an expert? No, and we should all make space for those people to inform and educate us, and defer to them. But just because you're not the expert doesn't mean it isn't okay to signal-boost and express that you care."

Ella is reassuringly honest about the areas in which her activism and knowledge fall short. "We're all in bubbles, even if we have the best of intentions not to be. It's not healthy to self-flagellate over that, but we do have to acknowledge it. You're never going to know 'enough' about all of the issues that are important, but I try to learn a little bit more about one thing at a time, follow new activists on Twitter, read more than headlines, ask questions. It feels small and insignificant, but it adds up. If you stop buying coffee every day, eventually you'll save a lot of money. So while any single latte seems like a small pinch, over time it adds up. Information and education are the same."

As our conversation draws to a close, and her call time for a night shoot – she's filming Denis Villeneuve's adaptation of scifi epic Dune in Hungary (quite a step up for what those agents called "a TV actress") – summons her away, I sneak in one last question about what season three of Handmaid's has in store. She laughs. "I've been doing this for fifteen years and it never gets easier to talk about a show without giving the game away. But there are some great surprises ahead. I'm really pleased with the arc I have in this story."

Of that, I have no doubt. It’s the very least this unique, candid and exceptionally engaging actress – on screen and off – deserves.

The Handmaid’s Tale season three is out now.