Lindsay Lohan's hoping Friday the 13th proves to be lucky when it comes to staying sober.

The 21-year-old actress checked out of rehab on Friday, her publicist, Leslie Sloane, confirmed to E! News. Sloane said the actress "successfully completed" a 45-day regimen at Promises, her home away from home since a booze-soaked Memorial Day weekend that ended up with her Mercedes wrecked and her in the hospital facing charges of driving under the influence after police found what was believed to be cocaine in her car.

"She has transitioned to an intensive outpatient program, which includes attendance at daily AA meetings, outpatient therapy and daily testing," Sloane added in a statement to People. "She's doing great. Lindsay is working hard on her sobriety and we are all supporting her."

The publicist added that "on her own, [Lohan] has also made the decision in support of her sobriety to wear an alcohol-monitoring bracelet. In part she is wearing the bracelet so there are no questions about her sobriety if she chooses to go dancing or dining in a place where alcohol is served."

The statement seemed to be a preemptive strike at naysayers, coming hours after Lohan turned up in Las Vegas, spending Saturday night at the hot spot Pure. She was there to celebrate the birthday party of one of her friends.

Sources tell E! News that Lohan downed Red Bulls and Voss water but not alcohol while dancing, spinning records in the deejay booth and hanging with fellow glitterati, including members of the Pussycat Dolls, Criss Angel and the MTV reality contingent of Lauren Conrad, Brody Jenner, Whitney Port and Frankie Delgado.

Lohan exited shortly before dawn, accompanied by her friends and Angel.

Pure was supposed to be the site of Lohan's blowout 21st birthday bash July 2. But after extending her stay in rehab last month, she canceled the Sin City celebration and opted instead to mark her birthday quietly with her mother and siblings.

Despite logging the 45-day tour of duty in Promises, it's not as if Lohan hadn't seen the sun since entering the seaside facility on May 28.

Over the course of her rehabilitation, Lohan left the grounds to work out, shop, see movies, roller blade and visit the beach, including a July 4 Malibu to-do—not your average daytrips while in detox but a far cry from Lohan's routine during her first stint in rehab.

Her setup at the swank Wonderland Center in Los Angeles' Laurel Canyon back in January had her leaving the facility during the day to run errands, lunch with pals and work on the thriller I Know Who Killed Me (due out July 27), and then returning to the facility at night.

"She is taking it one day at a time, as she is in it for the long time," Sloane said when Lohan checked out on Feb. 16, also noting that the actress would be continuing her treatment as an outpatient.

Apparently something didn't take that time around, because tales of Lohan's hard-partying ways persisted.

Read she was out all night partying again. She is stupid.

There's a surprise.

She is back behind bars again. She has some real issues and need s serious help. I wonder if the media would stop hounding these young "actors", if they would be in so much trouble.