New York - Andre Agassi used crystal meth periodically for "a year or so," the eight-time Grand Slam champion revealed in an interview with People magazine.

In his upcoming autobiography, Agassi admits he used crystal meth in 1997 and failed a drug test - a result he says was thrown out after he lied by saying he "unwittingly" took the substance.

"If you're going to tell your story, you owe it to yourself to tell it honestly," Agassi told the magazine in its latest issue. "Especially if you're going to call it Open."

New excerpts published on Friday reveal Agassi wore a hairpiece that nearly fell off at the 1990 French Open, became jealous during ex-wife Brooke Shields' appearance on Friends and how Shields put a photo of Steffi Graf - now married to Agassi - on the fridge for motivation to get in better shape before their wedding.

"It's a photo of the perfect woman, she says," Agassi wrote. "The perfect woman with the perfect legs - the legs Brooke wants."

Agassi also explains how he and Shields begin dating shortly after Christmas 1993 and connected by sharing their experiences with pushy parents. He also reveals that he stormed off the set of Friends becoming jealous when Shields had to lick actor Matt LeBlanc's hand.
"Have some more hand. I'm out of here," wrote Agassi, who said he consulted Shields on the book.

"A lot of our recollections were the same, but not the interpretations," Agassi told the magazine. "I tried to turn a harder lens on myself than on anyone else."

And it was the camera lens that haunted Agassi.

The tennis star's brother was sent running around Paris to find bobby pins to keep Agassi's disintegrating spiked-mullet weave from coming off his head before a match in the 1990 French Open.

"Of course I could play without my hairpiece. But after months of derision, criticism, mockery, I'm too self-conscious," he wrote. "Image Is Everything? What would they say if they knew? Win or lose, they wouldn't talk about my game. They'd only talk about my hair. I can close my eyes and almost hear it. And I know I can't take it."