Demi Lovato has seen her star power increase since taking a seat at the X Factor judges’ table… And now’s she’s using that higher profile to continue her fight against bullies.

The 20-year-old part Mexican singer/actress, who was recently named to Billboard.com’s 21 Under 21 list, has partnered with Secret deodorant to launch the “Mean Stinks” campaign to end bullying.

“I had a really tough time when I was in middle school,” says Lovato, who offered her support to a victim of bullying during a recent episode of The X Factor.  “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. I was a very emotional time for me, and all I wanted to do was get away.”

Following a short stretch in rehab to treat bulimia and cutting nearly two years ago, Lovato has been vocal in her stance against teenage bullying. On Thursday, the pop star surprised students at New York City’s Young Women’s Leadership School to discuss the program and encourage them to “gang up for good.”

Lovato asked girls to pledge to have a “Drama Free School Year” by painting blue nail polish on their pinky fingers – a symbolic pinky swear.

“I’ll definitely be wearing [the nail polish] starting soon,” said Lovato, who was recognized last December with a Do Something Award for her commitment to community service. “It’s a conversation starter: ‘Hey, why is your pinky blue?’‘This is a pinky promise that I’m not going to bully people, that me and my friends are ganging up for good.’”

Secret is donating $1 (up to $150,000) from each purchase of the company’s Mean Sinks Clinical Strength deodorant to the cause as part of the initiative.

More information on the program can be found via Secret’s Facebook Page.