Megan Fox had a boob job in the mid to late 2000's. After plastic surgery her breast size went up at least a cup. Megan Fox had a little stint of a plastic surgery craze where she had breast implants, a nose job, and Botox all in a short time period. Some of this surgery (excluding the later Botox injections) skyrocketed her career. She landed the Transformers(2007) role as a co-star with Shia Labeouf.
Megan Fox's boob size is more perky and full after plastic surgery. People may argue that she's just scrunching her boobs. But, all the pictures show that she definitely had a boob job.
She looks anorexic in the after photo. But, her boobs still look full and perky.