AUBURN HILLS, Mich. -- Mike Tyson's new medication seems to have him in an upbeat mood ... so far.

Tyson snapped at a couple of questions and once mocked opponent Andrew Golota at a news conference Tuesday, but he wasn't the glaring, surly presence he's been at past media gatherings.

At a public workout Monday at the Brewster Recreation Center in Detroit, the former undisputed heavyweight champion was downright relaxed.

Tyson claims he does not know what medication he is taking in place of the anti-depressant Zoloft, and the people around him aren't saying.

David A. Sebastian, chairman of the Michigan Boxing Commission, knows what the medication is but said it's up to Tyson to reveal it. Whatever it is, Tyson can fight on it against Golota on Friday night in the Palace at Auburn Hills.

"The medication is not performance-enhancing or impairing," Sebastian said. He said he talked to various doctors and they "insured me it was a non-issue."

When Tyson was using Zoloft, he was taken off it before fights.

Dan Goosen of American Presents, co-promoter of the fight with Hearns Entertainment, headed by former multiple champion Thomas Hearns, tried to play down the fact that a selling point seems to be the reputations of both men for dirty tactics.

Al Certo, Golota's trainer, said, "On this here show you're going to see the Marquis of Queensberry Rules done to a 'T.' I say to you, Michael, 'Let's show the people we can do it (fight fair).' "

Asked how long he thought the fight would last, Tyson said, "I don't know. As long as it takes to kill somebody."

At one point, Golota, who had little say, laughed at something Tyson said.

"He's over there laughing," Tyson said. "This is serious stuff. He won't be laughing Friday night."

As in all Tyson fights, the question of intimidation came up.

"That's his problem," Tyson said. "I don't have anything to do with that."

"I'm always afraid for any fight, this is boxing," said Golota, acknowledging the risks involved every time a boxer steps into the ring.

While Golota, who wore sunglasses throughout the news conference, appeared tight, he displayed humor while sitting in a dressing room waiting for Tyson to appear at the Palace.

Certo, a longtime trainer who also is a tailor in Secaucus, N.J., noted some thread unraveling in the right cuff of Golota's sports jacket.

"It's that cheap suit you wearing," said Certo, adding he could have done a better job.

"You can't make me a fighter, but you can make me a suit," Golota said.

The 10-round fight will be the featured match on a pay-per-view (SET) card beginning a 9 p.m. ET.

The Tyson-Golota match, expected to start about 11:30 p.m., will be immediately preceded by an IBF junior welterweight title defense by Zab Judah of Brooklyn, N.Y., against Hector Quiorz of South Gate, Calif.

Also to be televised is a 10-round lightweight bout between Alex Trujillo of Puerto Rico and Jose Juarez of Mexico, and a six-round women's bout between Muhammad Ali's daughter, Laila, of Los Angeles and Kendra Lenhart of Lenoir, Tenn.