Bruce Jenner has appeared on the front cover of Vanity Fair as a woman.
The former Olympic gold medal-winning decathlete and star of Keeping Up with the Kardashians, appears in women's clothing under the headline "Call me Caitlyn".
Caitlyn Jenner told Vanity Fair: “If I was lying on my deathbed and I had kept this secret and never ever did anything about it, I would be lying there saying, 'You just blew your entire life.'"
Her daughter, Kendall Jenner, a model as well as star of the reality TV show, encourage Jenner to be "free". She praised the cover and said: "Now that's a cover" and changed her Twitter profile picture to one of her with her sister, Kylie, and Jenner.
Caitlyn Jenner told Vanity Fair: "The uncomfortableness of being me never leaves all day long. I'm not doing this to be interesting, I'm doing this to live.
"I'm not doing this so I can hit it off the women's tee."
Jenner has not had genital surgery.
Only about one quarter of the 700,000 transgender women in the US do, Vanity Fair reported.
She spent 10 hours undergoing painful facial-feminisation surgery and had a panic attack afterwards, asking herself "What did I just do to myself?" and briefly seeing a professional counsellor.
Caitlyn Jenner's new Twitter account had 180,000 followers within 45 minutes of its launch.
Vanity Fair also released a black-and-white video which showed Jenner getting her hair done and posing in a long, off-the-shoulder gown.
The former athlete chose the name Caitlyn with a 'C' rather than a 'K' to make a clean break from the Kardashian clan, sources close to her told TMZ.
She also deliberately chose a revealing outfit for the Vanity Fair cover.
Jenner has begun filming a reality television "docu-series" about her transformation, which has led to friction with the Jenner side of the family.
The 1976 Olympic gold medalist's four children from before his marriage to Kris Kardashian, will not be taking part in the series.
She defended the decision to film a reality show, telling Vanity Fair: "I'm doing it to help my soul and help other people. You don't go out and change your gender for a television show."
Ending months of speculation that she was transitioning into a woman, Jenner gave her first interview on the subject in April, becoming the most high-profile American to come out as transgender.
Breaking her silence, the 65-year-old decathlon gold medalist described the feeling of being born with a male body and a “female soul”.
Known to older generations as one of the greatest Olympians in US history, and to younger generations as the patriarch of reality TV's Kardashian clan, Jenner declared it would be her last interview as Bruce, before re-emerging as a woman
"I have always been very confused with my gender identity since I was this big," admitted Jenner, lowering her hand to several feet above the ground.
While she asked to be addressed in the interview with male pronouns, speaking in front of millions of viewers, Jenner said: “My wh*** life has been getting me ready for this.
“I’d have been so mad at myself if I never explored that side of me. For all intents and purposes, I’m a woman.”
In the Vanity Fair interview Jenner was addressed as "she".
Jenner said she once contemplated suicide when her secret was about to become public.
She received a telephone call from a media outlet asking if he had just had a tracheal shave.
That led to her pacing her Malibu home thinking about shooting herself with a gun that was kept in the house.