Lady Gaga's Cocaine Use Exposed In New Tell-All Book, 'I'd Get a Delivery and Then Put on Some Bowie and Treat Myself In the Mirror'

Lady Gaga's former best friend, Brendan Jay Sullivan, revealed new details about the singer's cocaine use in a descriptive tell-all book, according to Radar Online.

The book, entitled, "Rivington Was Ours: Lady Gaga, The Lower East Side and the Prime of Our Lives," is set to be released at the end of August, and exposes Gaga's one-time addiction to the drug.

"I used to do bags and bags of it. Mostly when I was getting ready to go out, while I was putting on my makeup," Gaga allegedly confessed to Sullivan. "I'd get a delivery and then put on some Bowie and treat myself in the mirror. But I only ever did it alone. That was my one rule."

Sullivan also recalled a time when he walked in on Gaga rubbing white powder out of a carpet in her Manhattan apartment. "It's mint," she reportedly told him. "I wish it was coke."

Though Gaga has been open about the drug use that "led to disaster" in past interviews, Sullivan's stories are much more vivid.

Sullivan recalls Gaga and her friends at NYU were well known for their drug habits. They "would buy bags and bags of cocaine," Gaga shared with him. "I'd be out with my friends and you'd catch one of them on the phone with their dads, pretending they needed the money to eat or to buy books or something, and they'd hang up and go to the ATM and take out more money to party."

Sullivan also said he worried that the cocaine would ruin the "Born This Way," singer's career.

"I just agreed to score drugs for us both and spend our entire night smoking way too many cigarettes and talking way too fast about ourselves," he wrote about one night they spent together. "Then I started to worry. She had a recording session in L.A. the next week. What if it ruined her voice?"

Gaga has yet to respond to the claims.

Her new album, ARTPOP, is due out this November.