In the upcoming film "Crystal Fairy," Michael Cera's character finds himself on a quest throughout South America, seeking out a famed hallucinogen.

Cera's Jamie is on the hunt for mescaline, a drug found in the San Pedro cactus. He is joined by the so-called Crystal Fairy, played by Gaby Hoffmann. For the two veteran actors, however, the part of the film where they ingest the San Pedro wasn't simply acting.

"We drank the San Pedro, yeah," Cera told HuffPost Live on Wednesday. "We do it on-camera. When we drink it in the movie, it was the prop that we used. It was actual drugs."

Speaking about the cast's experience with the drugs, Cera explained, "Neither me nor any of the Silva brothers felt it, but Gaby Hoffmann had a different experience."

"Yeah, she lost her shit," Sebastián Silva, who directed the film, added. "It was real mescaline."

When Jamie takes the drugs in "Crystal Fairy," he becomes fixated with both his hands and a crab, staring at them as he trips out.

"I've tried the San Pedro a couple of times, and other drugs that are kind of in the same sphere. If you don't do crazy amounts, that's pretty much how you feel," Silva explained. "You're a little more sensitive to things. You sort of see the simple things again. You're sort of reborn."

"I was never confused about [it]. He's high," Cera said of playing a character that was very much under the influence. "There's a crab there and it's a fantastic thing for him to be looking at. It was pretty clear."

PHOTO GALLERY Sundance Film Festival 2013