In early 2011, Prepon guest-starred in an episode of the ABC police procedural drama "Castle" as an actress studying for the role of Nikki Heat, a character created by Nathan Fillion's title character. Prepon had been working on a web series, ', which she directed and edited, starring her then-boyfriend Scott Michael Foster. They had sold the series to Comedy Central. In February 2011, she was cast as the title character Chelsea Newman on the NBC sitcom "Are You There, Chelsea?", based on Chelsea Handler's 2008 book "Are You There, Vodka? It's Me, Chelsea". NBC cancelled the show on May 11, 2012. She guest-starred in the TBS sitcom "Men at Work". In mid-2012, Prepon signed on to co-star with Taylor Schilling in the Netflix original comedy-drama series "Orange Is the New Black", based on Piper Kerman's memoir '. She was cast as Alex Vause, a former drug importer and girlfriend of Piper Chapman (Schilling). The series premiered on July 11, 2013. Prepon was a regular in the first season, but appeared in only four of the 13 episodes in the second season. She returned as a series regular in the third season.