Part of That '70s Show featuring Topher Grace, Mila Kunis, Ashton Kutcher, Danny Masterson, and Wilmer Valderrama.
Rise to Fame
She left high school at 15 to train at Total Theatre Lab in New York, which is a considerable commitment for someone from Watchung, New Jersey. The audition tape she sent for That '70s Show got her cast as Donna Pinciotti, the red-haired straight man of the group. The same show launched Ashton Kutcher, Topher Grace, and Mila Kunis. The second act came through Netflix: as Alex Vause in Orange Is the New Black, the drug-importing ex-girlfriend of Piper Chapman, the role fit her considerably better than eight seasons of Fox teen comedy did.
In the Spotlight
She's moved behind the camera. She directed three episodes of OITNB while still acting in it, then directed all eight episodes of That '90s Show Part 3 in 2024, the sole director of an entire Netflix batch on the same franchise she started twenty-five years earlier. Off-screen, she was a Scientologist for roughly 17 years, publicly championed the church in 2014, left in 2016, and didn't say so publicly until 2021. Ben Foster filed for divorce in November 2024; Prepon counter-filed alleging 'habitual drunkenness' against Foster, while he alleged 'inappropriate marital conduct' against her. She's given journalists plenty of material without ever seeming like she sought any of it.
Side Notes
In her 2020 book You and I, As Mothers, she disclosed that her mother taught her bulimia. A modeling agency told her to lose 25 pounds at 15, her mother started weighing her daily and taking measurements, and they shared it as a bonding ritual for over a decade. Her father, an orthopedic surgeon, died during heart surgery when she was 13. Her mother has since been diagnosed with Alzheimer's. The wellness brand she built in her thirties isn't aspirational, it's corrective.