'Big Bang Theory' Star Mayim Bialik Reveals Makeover Ahead of Series Finale

Mayim Bialik is going out with the old and in with the new. Hot on the heels of a series wrap on The Big Bang Theory, the actress revealed a brand new makeover.

Bialik, 43, showed off her haircut on Instagram, thanking her stylist, who came highly recommended by fellow Big Bang star Melissa Rauch.

"A proper and loving shout out to [Jennifer Guerrero] who chopped off my old gross hair and gave me a new identity," Bialik captioned the image. "Jen has styled [Melissa Rauch's] hair for many years on [The Big Bang Theory] and when I asked Melissa if I could borrow Jen for this make over she said there's no one she would trust with me more than Jen."

She continued, thanking Guerrero for the new 'do. "Jen, thank you for inspiring me with layers and layers of the new me post-Amy!!! And thank you for holding my hand through this transition."

Bialik, who plays Amy Farrah Fowler on the longrunning sitcom, which airs its series finale Thursday night on CBS, shared a photo late last month of "one last time" on set.

"Here we go. One last time," she captioned a photo of the iconic Warner Bros. water towers. She told Closer Weekly back in December that she was "emotional" about the fact that the series was finally coming to a close after 12 seasons and that she wanted to "capture every moment."

"Every week kind of feels like, 'This is the last time we'll be doing this kind of script.' It's been such a long run, and so it's kind of hard to imagine life after this," she said.

More recently, Bialik told Us Weekly that she and her co-stars were each gifted apartment doors as a little piece of the Big Bang set to keep forever.

"Actually, the set design department gave us all an apartment door," she said. "That's cute. So I might put that outside of my front door of my house."

Ahead of Thursday's two-part finale, photos from the episodes were released, teasing some Sheldon and Amy moments — meaning Bialik and co-star Jim Parsons' appearances should be prevalent.

The first finale episode, titled "The Change Constant," will reportedly feature some big news coming down the pike for Amy and Sheldon, although it's not immediately clear what kind of news it will be. Fans should also expect to se some series moments between the pair, according to the photos released Sunday.

The two-part series finale of The Big Bang Theory airs Thursday, May 16 at 8 pm. ET on CBS.