Adult Swim has officially renewed Common Side Effects for a second season. The adult animated series, which premiered in February, was created by Joseph Bennett (Scavengers Reign) and Steve Hely (Veep), with executive producers Mike Judge (King of the Hill) and Greg Daniels (The Office).
The show follows former lab partners Marshall Cuso (Dave King) and Frances Applewhite (Emily Pendergast) as they struggle to bring a revolutionary cure-all mushroom to market, despite resistance from powerful pharmaceutical companies and government forces. The voice cast also features Mike Judge, Martha Kelly, and Joseph Lee Anderson.
The renewal comes just ahead of the season 1 finale, Raid, set to air on March 30. Adult Swim president Michael Ouweleen praised the show for redefining adult animation, while the creators expressed excitement about continuing their story, describing the series as a “wonderful mushroom dream.”
Common Side Effects renewed for season 2
What it might mean for Common Side Effects
The production timeline for Common Side Effects Season 2 remains uncertain. However, looking at the first season’s timeline offers some clues. The show initially entered development in 2019 but wasn’t officially announced until June 2023. From that point, it took about a year and a half to premiere in January 2025. If Season 2 follows a similar pattern, fans might have to wait until around September 2026 for new episodes.
While the episode count for Season 2 hasn’t been confirmed, the first season consists of 10 episodes. The renewal means the story will continue beyond the Season 1 finale. Unlike many Adult Swim shows that follow an episodic format—such as Rick & Morty—Common Side Effects is more serialized, meaning the next season will likely build on the current story. The finale may wrap up one part of Marshall and Frances’ journey, only for a new challenge to emerge.
The quick renewal suggests Common Side Effects has strong momentum and could become a major player in Adult Swim’s lineup. However, its serialized format raises questions about how long the story can sustain itself compared to long-running shows like Robot Chicken (11 seasons since 2011) or Rick & Morty (renewed through Season 12).
The Season 1 finale airs Sunday at 11:30 p.m. ET on Adult Swim and will also be available on Max.