The singer also said she drew on her own experiences in the music industry for her role playing Ally, an aspiring singer in new movie A Star Is Born.
“I was told when I was first starting out that I should get a nose job, but I didn’t because I wanted to be who I was,” she told Sky News on the red carpet of the film’s London premiere.
Abandoning her performance persona to draw on past experiences for the movie “was a vulnerable experience,” she said.
A Star Is Born, which stars Gaga alongside Bradley Cooper in his directorial debut, is a remake of a movie classic first made in 1936.
It explores the love story between an ageing rock star and a young singer whose career he champions.
As well as being inspired by her own life, Gaga – whose real name is Stefani Germanotta – said she was aware of the differences between her own start in music and that of the character she plays.
“I really believed in myself when I started out pounding on doors to break down all of the barriers in the music industry, I really had courage,” she said.
“She doesn’t have that, she’s not brave and she’s not full of self-confidence.”
Speaking to Sky News, Cooper said Gaga’s performance had come from a “deep, honest place”.
“It’s a tribute to her character and how she makes people feel, and why she has so many millions of loyal fans is because they feel that she’s authentic,” he said.
Gaga returned the praise for the co-star and director, saying Cooper had made her “feel so happy” on set.
“It was like a sanctuary for making art,” she said. “It was wonderful.”
Fans clamoured to catch a glimpse of the stars of Gaga’s debut movie at its premiere UK screening on Thursday – and some of other actors in the film were eager to catch up with her too.
Shangela – who was hand-picked by Gaga to play her drag mother in the film – ran to kiss the star as she passed by on the red carpet.
“When you see the Queen pass by you must pay homage,” she said, adding she was a “little monster” – another word for Lady Gaga fans.
The movie opens in the UK on 3 October.