Inside Lindsay Lohan's 26th Birthday Bash

Party time for Lindsay Lohan!

The Liz & Dick actress let loose during her birthday bash at West Hollywood nightclub Bootsy Bellows early Sunday. The party took place one day ahead of her 26th birthday, which she celebrates on Monday.

A little after midnight, the actress, clad in a tight pink minidress, hit up the hotspot with a group of her close friends.

"She sat at her table close to the DJ," a witness tells Us Weekly. "[Up-and-coming group] Speakerz was there and performed several songs for Lindsey. She was loving them and looked happy and carefree as she danced all around with her friends."

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Later, the star was presented with cake and Sprinkles Cupcakes, and the whole room broke out singing "Happy Birthday."

"There was a ton of alcohol at Lindsey's table, however she didn't appear to be drinking," the witness adds.

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Perhaps it's good that the headline-making actress is laying low, especially after her scary June 15 incident where she was treated for exhaustion.

"Note to self.. After working 85 hours in 4 days, and being up all night shooting, be very aware that you might pass out from exhaustion & 7 paramedics MIGHT show up @ your door... Hopefully they're cute. Otherwise it would be a real let down," Lohan posted to her Twitter following the incident.

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Another way the star is soothing her jangled nerves: by smoking two packs of cigarettes on the set of the upcoming Liz & Dick biopic.

"Literally every time she finishes a scene she lights up another cigarette," a source told Us last month. "You can hear the crew saying, 'That's cut -- get a cigarette for Lindsay.' "

"Lindsay has been working hard, but without the nicotine she probably could not make it through as she appears stressed at times and they do seem to calm her down," the source added.

This article originally appeared on Usmagazine.com: Inside Lindsay Lohan's 26th Birthday Bash