The actress is believed to have boosted her bust from an A to a C cup.

“She couldn’t be happier,” a source told National Enquirer magazine. “She’s wanted bigger boobs since she was 17, but the timing and scheduling was just never right. She finally decided to do it right after the holidays.”

Hayden recently debuted a new hairstyle, dying her trademark blonde locks red. It has been claimed the make-over could have been a cunning way to drawing attention away from her increased chest size, with plastic surgeon Dr. Anthony Youn telling the publication Hayden seems to have undergone a breast augmentation.

“Her breasts appear to have gone from an A to a C, judging from the photos. She looks even more like a superhero than she did in drama series Heroes,” he said.