From gaining (and losing) weight to enduring 10-hour days in the makeup chair, these stars have changed their looks in the name of entertainment

Source: http://www.ivillage.com/celebrities-who-changed-their-looks-movie-roles/1-b-401981?dst=iv%3AiVillage%3Acelebrities-who-changed-their-looks-movie-roles-401981

Giulianna Ramirez Grace Park Gretha Cavazzoni Gwen Stefani Halle Berry Hayden Panettiere Haylie Duff Heidi Klum Heidi Montag Hilarie Burton