Caitlyn Jenner is experiencing regret about undergoing a sex change and “there’s a chance she’ll de-transition in the next few years,” according to the author of a new book on the Kardashian family.

Ian Halperin, author of “Kardashian Dynasty: The Controversial Rise of America’s Royal Family,” told The Wrap that multiple sources had told him that Jenner, the gold-medal Olympian who was formerly married to Kris Kardashian Jenner, has been miserable. “One source confirmed to me Caitlyn has made whispers of ‘sex change regret,’ hinting she might go back to being Bruce Jenner,” Halperin said.

A Jenner representative told the New York Daily News, “Not worth commenting on such an idiotic report. Of course it’s not true.”

Jenner, 66, has been been a high-profile advocate for transgender issues since announcing her new identity last June. She chronicled her transition on the reality TV show “I Am Cait” and was presented with the Arthur Ashe Courage Award at the ESPYs last summer. Still, Helperin said the transition has been difficult.

“It hasn’t been easy for Caitlyn. It’s been very hard,” Halperin says a friend of Jenner’s told him. “She’s thrilled she has raised awareness about how transgender people have long been discriminated against, but I think there’s a chance she’ll de-transition in the next couple years. I don’t think it would surprise anybody in her inner circle. It has been much harder than she anticipated. My heart goes out to her and I know her true friends will be there to support her on whatever path she chooses.”

He added that multiple sources had told him that part of the reason Jenner, who has been married three times and has six children, may de-transition is that she is interested in women. According to Halperin, multiple sources close to the Kardashian family told him that Jenner retains her interest in females.

“She’s still into women and wants to meet the right one,” Halperin says a friend of Jenner’s told him.

With the premiere of Caitlyn Jenner's documentary series about her gender transition, "I Am Cait," here's a look back at the former athlete and reality TV star's career. (Editor's note: This video has been updated.) (Nicki DeMarco, Thomas Johnson and Emily Yahr/The Washington Post)

Earlier this month, Jenner visited a Brooklyn school and spoke with Nicholas Kristof of the New York Times about being the face of transgender people.

“Maybe this is the reason God put me on this earth, to tell my story, to try to make a difference in the world,” Jenner said. “Because this story and this issue — trans, gender identity, nonconforming, whatever it may be — is bigger than what I did back in ’76 and winning the Games. It’s bigger than breaking world records and doing all that kind of stuff. This is about life. This is about life and death. People destroy their lives over what we all kind of deal with.”

Jenner admitted that she had never met a transgender person until a year ago, but has increasingly been finding her voice. Recently, she has been speaking out lately about North Carolina’s bathroom law, which requires transgender people to use the restroom that conforms with the gender listed on their birth certificate.

“For so many years, little Caitlyn has lived inside,” she said, “and Bruce kind of took over the world, and did his thing. It was time to put him inside and let’s let her live, okay?”