Hollywood's prettiest stars sometimes have to show their hideous sides.
Ugly Then: Amanda Seyfried probably wishes she could have had an out-of-body experience when she had to get grotesque for her part in the 2009 dark comedy Jennifer's Body.
Pretty Now: Instead of dirty hair, these days Seyfried is sporting luscious blonde locks. Her secret? "I only wash my hair every few days," she says.
Ugly Then: America Ferrara was forced to go through her awkward phase for years while playing an assistant at a magazine on Ugly Betty.
Pretty Now: Now that she's blossomed into a beautiful star, Ferrera loves to go on never-ending dates. Her favorite activity? "Dancing into the wee hours with my husband, then ending with breakfast as the sun comes up," she says.
Ugly Then: Angelina Jolie won a pretty prize, an Oscar for Best Supporting Actress, for her acting and for her bedraggled looks in the 1999 film Girl Interrupted.
Pretty Now: Jolie shines for her dedication to helping others. "What she's accomplished after the film in terms of humanitarian stuff, I'm just really happy she did that," says the actress' Girl Interrupted costar, Winona Ryder. "It's really great to see she's found her calling in her personal life."
Ugly Then: Anne Hathaway may not have liked her look in Les Miserables, but she certainly wasn't crying when she won a Best Actress Oscar for playing Fantine in the 2012 film.
Pretty Now: Hathaway has since grown out her hair and looks just as glamorous as ever.
Ugly Then: Cameron Diaz plays a dowdy pet store employee in the 1999 hit Being John Malkovich.
Pretty Now: Today Diaz is known for playing parts that call for her to be looking her hottest, like the summer film Sex Tape.
Ugly Then: Christina Ricci made a real pig of herself in Penelope, the 2008 movie about a girl cursed with a snout. "It took about an hour and a half," Ricci has said of getting the fake nose fit every day before shooting. "It's not fun to have something glued to your face."
Pretty Now: Despite having to look ugly for roles occasionally, Ricci is determined to keep doing what she loves. "I am really happy just acting right now and I would like to focus on being the best I can be as an actress," she says.
Ugly Then: Demi Moore shaved her head to become a soldier for her role in 1997's G.I. Jane.
Pretty Now: Moore believes that she is more beautiful today than ever thanks to a healthier self-image. "I find peace when I don't see my body as my enemy, when I step back and have appreciation and look at all that my body has done for me," she says. "It's allowed me to give birth to three beautiful children, allowed me to explore different roles as an actor, allowed me to be strong."
Ugly Then: In 1999 Drew Barrymore could still make audiences believe she was a girl who had yet to find love in Never Been Kissed.
Pretty Now: "I think happiness is what makes you pretty. Period. Happy people are beautiful," insists the star.
Ugly Then: Getting into character as a homely helper in Nanny McPhee required Emma Thompson to have a lot of patience. "To journey into such hideousness, it's a lot of sticking on and painting," explains the actress. "It's a wig, and then the nose, and the lobes, and the brow, and the wart, and they all get stuck on."
Pretty Now: Thompson's looks flawless without the magic of movie makeup.
Ugly Then: Felicity Huffman manned up to play a transsexual in Transamerica.
Pretty Now: Huffman looks anything but a desperate housewife these days.
Ugly Then: Salma Hayek really raised unibrows when she signed on to star as the surrealist Mexican painter Frida Kahlo in Frida.
Pretty Now: Though Hayek is stunning, she admits, she has never bothered to try to be as beautiful as possible. "Exercise, or not eat dessert. Or not drink alcohol. I could make bigger efforts," she says. "I don't think my first priority in life has ever been beauty. It's a little bit of a rebellious spirit in me. There is more to me than looks, of course."
Ugly Then: Halle Berry went plain Jane for her role as Leticia in the 2001 drama Monster's Ball.
Pretty Now: Though she's known as one of Hollywood's most beautiful women, Berry doesn't think she is. "To be totally honest, most of the time I think I'm ugly," she admits. "I see myself without makeup every morning and that's why I don't have illusions anymore."
Ugly Then: Jennifer Lawrence was far from glamorous when she played the part of a girl searching for her drug-dealing dad in Winter's Bone.
Pretty Now: The entertaining and down-to-earth actress' funny red carpet antics make her flawless in fans' eyes.
Ugly Then: Jessica Biel is decidedly un-glam in her role as a nurse whose son is kidnapped in the 2012 thriller The Tall Man.
Pretty Now: Luckily, Biel has resuscitated her looks since playing the dowdy character.
Ugly Then: This beauty played a serial-killing beast in the 2003 crime drama Monster.
Pretty Now: The actress finds that the need to always look amazing comes at a price. "With such demands for perfection and an eternal obsession with youth, I'm not surprised that we all become part of this beauty race that seems to be getting crazier," she notes.
Ugly Then: Not even glitter, rainbows or butterflies could make Mariah Carey look good for her role as a welfare caseworker in the 2009 movie Precious.
Pretty Now: In reality, Carey just loves to go glam, whether she's strutting her stuff on the red carpet or hanging out at home.
Ugly Then: Even when possessed by a demon in the horror flick Jennifer's Body, it's debatable whether or not Megan Fox really becomes all that ugly.
Pretty Now: Fox is always a fox on the red carpet.
Ugly Then: Michelle Williams sported a boyish cut in her role as Wendy, a drifter in Wendy and Lucy.
Pretty Now: Williams believes growing older has made her a better person in real life. "I don't feel as shy or nervous or self-conscious," she says.
Ugly Then: Sandra Bullock played an FBI agent who went undercover as a beauty queen in 2000's Miss Congeniality.
Pretty Now: Bullock now shines thanks to that glow she gets from her adorable son Louis.
Ugly Then: Like actresses before and after her, Natalie Portman completely transformed her look by shaving her head in the 2006 film V for Vendetta.
Pretty Now: With the movie in her rearview mirror, Portman can let her hair down again.
Ugly Then: Even Rooney Mara got sick of how her look in Girl with the Dragon Tattoo became the topic of every conversation. "Just because the character listens to an iPod and wears black nail polish, she's goth," she says.
Pretty Now: Rooney can finally let the world see another side of her image. "I didn't even have pierced ears," she says of her look in the movie that made her famous. "They put four holes in each ear, and, weirdly, that hurt the most."
Ugly Then: Uma Thurman didn't look so adorable as a bespectacled dork in Batman and Robin back in 1997.
Pretty Now: Thurman became more and more confident in her looks as she grew older. "I spent the first fourteen years of my life convinced that my looks were hideous," she says.
Hollywood’s prettiest stars sometimes have to show their hideous sides.