Pics Of The Leading Ladies From The Big Bang Theory, Then And Now

We're still not over the fact that "The Big Bang Theory" ended in 2019 after giving fans 12 glorious seasons of nerdy physics talk, a friends-to-lovers storyline, and a heartwarming wedding between two of the main characters. The show was popular enough to go on for more than a decade, but sadly, Jim Parsons wanted to move on to other projects. That meant that the other actors had to as well, and it's amazing to see just how much they've transformed since playing their iconic roles.

Some of the leading ladies of "The Big Bang Theory" and their real-life partners welcomed kids after the series concluded, while others went on to make big moves in their careers. With almost 20 years spanning from the premiere to now, you may not recognize the main cast. From fresh-faced ingenues to celebs over 40 that prove style gets better with age, our favorite "TBBT" girlies have come a long way.

No sitcom is complete without the girl next door, but Penny from "The Big Bang Theory" was so much more than that. Played by Kaley Cuoco, Penny anchored the men on the show, teaching them much-needed social skills. Back in 2007, the actor was in her early 20s with gorgeous blond locks, and Cuoco has had a head-turning hair transformation since. In recent years, she switched up her 'do for a darker shade, giving her a more mature, edgier feel, and her skin is just as smooth and youthful as ever.

No one was more suited to play Bernadette than Melissa Rauch, who managed to create a character that was sexy, smart, and a little bit terrifying at the same time. The New Jersey native joined "The Big Bang Theory" cast in Season 3 as Howard's love interest, and soon became a series regular. At the time, Rauch rocked side-swept bangs that were popular during the mid-aughts, but these days, she sports a waterfall fringe, which instantly makes her look fresh and on-trend.

Mayim Bialik joined "The Big Bang Theory" at the end of Season 3, and her role as a neuroscientist named Amy wasn't much of a stretch, as the actor also has a PhD in neuroscience from UCLA. However, unlike her character, who was a bit of a know-it-all, Bialik remains humble, even as a big star. She's all about aging gracefully, and told Yahoo! Life, "I am a person who has not engaged in any facial treatments or injections or anything. It's just a personal choice."

While Laurie Metcalf wasn't one of the leads of "The Big Bang Theory," she played the pivotal role of Sheldon's mom, Mary Cooper. When Metcalf first appeared in Season 4 Episode 1, she was already a television icon, having starred in "Roseanne" for its entire nine years on air during the late '80s and '90s. The Coopers were such a hit that a spinoff, "Young Sheldon," was created in 2017, but since Metcalf wasn't the right age to play his mom, her real-life daughter stepped in.

Christine Baranski's acting career is so impressive that "The Big Bang Theory" is just a blip on her resume, but that doesn't make her any less memorable. As Leonard's formidable mom, Dr. Beverly Hofstadter, she made her debut in Season 2 and remained a side character throughout the years. While Baranski had memorable roles in "Mamma Mia!" and "Chicago," many still recognize her from "TBBT." She told People, "More often than not, they point to me and say, 'Leonard's mother! ... There are worse things to be called, believe me."

Laura Spencer was already a working actor when she joined "The Big Bang Theory" in Season 7. Although she came in a bit later and was initially an extra as Raj's girlfriend, she eventually became a regular on the sitcom. Known as the quirky dermatologist fascinated by death, Spencer's character brought her own brand of weirdness to the cast. After the series finale, she continued to grace the screens with her fiery red hair and reunited with Melissa Rauch as a guest star in "Night Court."