Aniston, 53, said that trying to get pregnant was a “challenging road” for her and that she underwent IVF to try and conceive, but “the ship has sailed”.
She posted several photographs from her cover shoot with Allure magazine on Instagram, with the caption: “End of an era. Thank you Allure for making me the cover girl of your very last print issue.”
Theroux, who was married to Aniston from 2015 to 2017, left a fist bump and heart emoji in the comments under the post in a show of support for his ex-wife.
The Friends star was also married to Brad Pitt from 2000 to 2005.
She told the magazine in an interview published on Wednesday (9 November): “I was trying to get pregnant. It was a challenging road for me, the baby-making road.
“All the years and years of speculation… It was really hard. I was going through IVF, drinking Chinese teas, you name it. I was throwing everything at it.
“I would’ve given anything if someone had said to me: ‘Freeze your eggs. Do yourself a favour.’ You just don’t think it. So here I am today. The ship has sailed,” she added.
Elsewhere in the interview, Aniston also addressed some of the rumours about her divorce from Pitt and denied the narrative that she “just cared about [her] career” instead of wanting to start a family with him.
“God forbid a woman is successful and doesn’t have a child,” the Morning Show star said. “And the reason my husband left me, why we broke up and ended our marriage, was because I wouldn’t give him a kid.”
She criticised the narrative, adding: “It was absolute lies. I don’t have anything to hide at this point.”
Last year, Theroux opened up about his 2018 divorce from Aniston in a candid interview with Esquire and said they have “remained friends”.
“Like it or not, we didn’t have that dramatic split, and we love each other,” he said. “I’m sincere when I say that I cherish our friendship. We can not be together and still bring each other joy and friendship.
“Also, she makes me laugh very, very hard. She’s a hilarious person. It would be a loss if we weren’t in contact, for me personally. And I’d like to think the same for her.”