She's come a long way, baby.
See how Jenny from the Block turned into a worldwide beauty icon.
See the good and the very, very bad.
Take a look at the actress' pixie, blonde makeover and many others.
It's the former pop star's 40th birthday, and we're celebrating even her less fortunate looks.
We're celebrating the singer's transformation with a look back at her many hairstyles.
You won't believe some of the 'dos Jen sported before finding her signature hairstyle! Here, we chart her many looks through the years.
She's come a long way since her Dancing With the Stars days!
Oh, how we miss her Angela Chase hair color.
Oh baby, baby! Some of these hairstyles are downright scary.