Selena Gomez has lashed out at a fan for bullying.

The 21-year-old pop star came to the rescue of a user on Instagram who posted a photo of her wrist after she appeared to have injured herself this week.

When another Selena fan encouraged the girl to “cut”, the singer chimed in with contempt.

“This is ridiculous… My fans don’t do this to others. That’s not what I stand for so you can gladly stop being a fan of me. I only encourage love, confidence, kindness,” she wrote.

The singer then addressed the user who appeared to be harming herself.

She also took the opportunity to dissuade others from following suit in effort to win her attention.

“You are gorgeous just the way you are. Don’t you ever attempt that sh*t again. Ok?” Selena continued. “I love you too much for you to be doing that. PS. To all of my fans, don’t ever think this is fun to get attention. It’s just wrong. I love you all just the way you are.”

Selena has reached out to troubled friends in the past.

Demi Lovato appeared to credit the star with saving her life during her 2010 stint in rehab for substance abuse.

According to E! News, Selena was one of the few friends who visited her.

"I can't wait to talk about the people who have never taken ANY credit for being a huge part of saving my life, and why I'm alive today...." Demi tweeted earlier this month.

Selena may be dealing with some health woes of her own.

The star, who suddenly cancelled the remainder of her world tour earlier this month, was diagnosed with Lupus a couple of years ago and recently suffered “flares”, according to Popdust.

“She knows that she needs to take some time to address the disease and look after herself better if she wants to live a full and healthy life,” a source said.