Jack Osbourne lashed out at “f–king insane” trolls criticizing his weight loss in a fiery video.

“I cannot believe I’m having to actually make this,” the reality star told his Instagram followers on Tuesday.

“If I see one more article written about me saying how I’m ‘sick,’ I’m ‘grossly underweight’, [that I’m] ‘health crisis Jack’ … it’s f–king insane,” he said.

Osbourne pointed out that he hasn’t lost any weight since he finished competing on the UK reality show “I’m a Celebrity … Get Me Out of Here!” six months ago.

“I’ve been the same f–king weight,” he declared. “The only difference is I shaved my beard and opted for a creepy mustache. That’s the only f–king difference.

“I’ve been slowly but consistently losing weight for the last three and a half years,” Osbourne continued. “I shot up to about 220 pounds about three and a half years ago and decided that I wanted to make some changes, so I did.”

He asked, “What’s the big f–king deal? I’m 5 foot 8 and a half and 155 pounds. It is perfectly healthy.”

The “Portals to Hell” alum, 40, concluded, “The fact that I even have to say this blows my mind. My entire life I was just brutalized by the press about being overweight, and the fact that I get down to a healthy weight, now I’m criticized even more? Get f–ked.”

Several stars took to the comments section to send support to the youngest child of Ozzy and Sharon Osbourne.

“Love you Jack. You tell em!!!” wrote Bob Saget’s widow, Kelly Rizzo, while wrestler Chris Jericho added, “Don’t listen to the haters dude. You look great.”

Osbourne previously attributed his dramatic weight loss to lifestyle changes, from rigorous fitness training to ditching drugs and alcohol.

While on “I’m a Celebrity … Get Me Out of Here,” he lost additional weight surviving on a basic diet of rice and beans.

His sister Kelly Osbourne, notably, has also blasted comments about her weight loss in recent months.

“There is a special kind of cruelty in harming someone who is clearly going through something,” she wrote in February, referencing Ozzy’s July 2025 death. “I won’t sit here and allow myself to be dehumanized in such a way!”