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Mimi (a.k.a. Mariah Carey) doesn't enjoy being emancipated from her glamorous self.

The singer returns to acting in the buzzed-about gritty drama "Precious," playing an 80s-era hard-knock social worker named Mrs. Weiss. And her look in the film -- bad hair, dowdy clothes, even a faint mustache -- is as far from fabulous as she's ever been.

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"It wasn't just de-glamorized," Carey, 40, told Usmagazine.com at Sunday's "Precious" premiere at Mann's Theater in Hollywood. "They added some hideousness on top of that too. I drank some ugly juice," she said, laughing.

It's not the first time the music star has told Us about the humbling experience, either. At a "Precious" event in Toronto Sept. 13, she noted "I couldn't even look in the mirror! It was tough."

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Gabourey Sidibe, "Precious"' young star, told Us in Toronto that Carey "hated" her time in the makeup truck. "She hated her wardrobe! It was the funniest thing. Like the first day of school or something, where you're not wearing the right socks and the whole outfit's ruined."

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"I wouldn't let her look at herself!" added the film's director Lee Daniels. "She just trusted me. I knew she was serious [about her performance]."

But once filming was through, Carey used her beauty school education to make things right again. "I just dealt with hair first -- I have my own little tricks!"