Demi Lovato has already been pretty candid about her experiences overcoming drug use, self-harm and bulimia, but now she's opening up about a new cause: bullying.

The singer and X Factor judge signed on as the official ambassador for Secret deodorant's "Mean Stinks" anti-bullying campaign, which encourages girls to "gang up for good." The program asks girls to promise to keep the peace in school by making a pinky swear pact, symbolized by wearing blue polish on that finger, according to E! Online. "I'll definitely be wearing [the nail polish] starting soon," said Demi. "It's a conversation starter: 'Hey, why is your pinky blue?'"

Related Article: Demi Lovato & Simon Cowell Duke it Out on 'Conan'

Related Article: Demi Lovato: Back to Bangs!

Demi said she wants to help end bullying because she was the victim of it growing up. "I had a really tough time when I was in middle school," she said to People Magazine. "People would write 'hate petitions' [about me] and send them around to be signed. They'd have CD-bashing parties of my demos. They'd come to my house, stand across the street and yell things. It was a very emotional time for me, and all I wanted to do was get away." She also said the abuse partially contributed to her rehab stint two years ago.

As of this moment, Demi is the biggest celebrity to join an anti-bullying campaign. Yet another reason to love this girl.

What do you think of Demi's anti-bullying project?

Photos courtesy of Secret Deodorant and Getty Images