The `Sucker Punch` actress - who has been romantically linked with actor Josh Hutcherson since splitting from long-term boyfriend Zac Efron last December - does`-t always feel confident about her appearance and has days where she can`t be bothered to make an effort.
She said: "I can have an ugly week. I go through days upon days where I just will not want to put on make-up or do my hair and just be in sweats."
Vanessa recently worked on `Beastly` and found it "fascinating" having to kiss Alex Pettyfer while he wore prosthetics to disfigure his appearance.
She said: "It was really interesting because of the make-up and prosthetics. When you strip a person of their looks, their whole demeanour is different.
"I personally found it extremely intriguing because there is a mystery behind it. It makes it that much more romantic."