Common Side Effects Creators Tease Ambitious Season 2

Common Side Effects premiered in February 2025. Featuring trippy animation and the voice of Mike Judge, the series follows a fungus expert named Marshall Cuso (Dave King). Marshall discovers a rare species of Blue Angel mushroom that can seemingly cure any disease or physical injury. His discovery sparks a conspiracy thriller as the federal government and the pharmaceutical industry race to take control of the opportunity.

The Adult Swim series offered a redemption of sorts for co-creator Joe Bennett after his previous project, Scavengers Reign, was canceled by HBO Max, moved to Netflix, and then shelved. Bennett co-created Common Side Effects with Steve Hely, who worked on Veep.

At a New York Comic Con 2026 panel, Bennett and Hely announced that season 2 of Common Side Effects will debut Sunday, Jan. 24 at 11:00 p.m. ET on Adult Swim and stream the next day on HBO Max. Ahead of the announcement, Polygon watched the first episode of season 2 and spoke with the creators about the direction of the show.

There are light spoilers for Common Side Effects season 2 episode 1 in this article.

Polygon: Common Side Effects season 2 introduces a new villain who seems to be hunting for the Blue Angel mushrooms. Can you tell me any more about this character?

Steve Hely: The character’s name is Thomas, and there will be some backstory that’ll unfold over the course of the season.

Joe Bennett: He’s voiced by Bob Stephenson, who played Sam in Scavengers Reign.

Steve Hely: Our idea — without giving too much away — is that he came to the mushroom in his own way, and he’s formed a kind of a religious obsession with it. When he learns that other people have it and are using it, he becomes obsessed with stopping them.

Joe Bennett: Similar to how we try to treat any of the villains in our show, we want to give him as much dimension as possible. You empathize with elements of Thomas. You kind of understand where he’s coming from.

That’s interesting, because he’s not very sympathetic in the first episode. He’s more like the Terminator.

Joe Bennett: Yeah, he’s like an Anton Sugar.

Steve Hely: We always try to make sure there’s a way to see it from their point of view. We’ll get to that in the course of the season.

Season 2 also seems to be exploring the idea that people who use the Blue Angel mushroom can have shared hallucinations. Where is that plotline headed?

Joe Bennett: That is going to be an ongoing thread that’ll sort of run parallel with the reality world throughout the season. Obviously, this new character is kind of familiar with that and you’re going to do a lot of interweaving. For Marshall, the deeper he’s getting, he’s unpacking a lot of stuff that he didn’t know was possible.

Steve Hely: And maybe getting a little scared of it.

Joe Bennett: It’s a Pandora’s Box kind of a thing.

Steve Hely: There is a side effect to this thing, and the limits of it are not quite understood. The idea that everybody who takes this mushroom is connected in this other realm opens up a lot of possibilities and creates some fun opportunities for very cool animation.

How has the animation evolved in season 2?

Steve Hely: This is a very ambitious season. They’re going to a lot of different locations. There’s a higher shot count, which is always a little bit of a burden on the team. There’s a lot more in the Portal World that is bigger scale overall.

Joe Bennett: After season 1, we can now flex in these other areas and geek out on it. There’s more rough animation that we were able to do. There’s more stuff that we’re able to do in-house and take bigger swings on with these action scenes.

Season 1 had some really interesting things to say about both the good and evil sides of the pharmaceutical industry. Where does that go in season 2?

Steve Hely: Our characters confront some of the challenges of making something safe and getting it distributed. They start to realize that the people they think of as their enemies might have evolved that way for perfectly practical and sensible reasons. That’s part of the theme of the show: You might hate the current system, but setting up a different one is very challenging.

Mike Judge played a pretty big part in season 1 as the pharmaceutical executive, Rick. He also executive produces the show. How involved is he in season 2?

Steve Hely: He reads everything, and he’s awesome to bounce stuff off of.

Joe Bennett: Rick’s got a pretty big role in season 2. He’s actually one of my favorite characters in this season.

Before I go, I need to ask about Scavengers Reign. Is there any chance we’ll ever get a second season of that show or is it dead?

Joe Bennett: TBD. There’s a huge fan base. But I don’t know. We’ll see.

Steve Hely: You’re gonna be in the nursing home, saying, “We’re working on it! One day!” [laughs]

Joe, you’ve also got a new animated show coming out on Netflix called Dealies. Where does that sit in your body of work?

Joe Bennett: My earlier original shorts are more sort of like comedy-based and comedy-focused. I think it’s kind of pulling a lot more from that sort of thing. It’s an episodic comedy series where a bunch of current characters work together in a big box store.

Steve Hely: Well, it’s very Joe Bennett in that it’s very character-based. Very observed. Kind of an offbeat kind of character. Exists in our real world, but capturing weirdness.

Joe Bennett: It’s a big box store versus mom-and-pop brick-and-mortars. There’s an antique store across the street that is really struggling to stay in business. So it’s sort of playing with that.

How many seasons of Common Side Effects would you like to make in total?

Steve Hely: We want to tell 40 to 100 seasons. We see it as this constantly unfolding novel with many chapters that can expand in different directions and come back around.

Source: Polygon