The actor played stockbroker Donnie Azoff in the film and drug use ran rampant in his portrayal. But, while the "cocaine" was actually crushed up vitamin powder, Jonah told HBO's Bill Simmons that he ended up getting sick and developed bronchitis from all the snorting.
"I had to be hospitalized. If you ingest that much matter into your lungs you'll get very sick, and we were literally doing fake coke for, like, seven months, every day," he said on "Any Given Wednesday." "I never had more vitamin D in my entire life; I could have lifted a car over my f---ing head!"
The film went on to win a Golden Globe.
For his new film "War Dogs," the actor again dabbled in fake drugs as he plays real life arms dealer Efraim Diveroli.
"It's interesting pretending to be on drugs. I use music," he said of how he gets into a fake drug-induced state. "I'll make a playlist for every scene, so I'll try to make, like, music that (made me feel) jittery and chaotic ... and then just drink a ton of coffee and Red Bull."
"War Dogs" depicts the bizarre real life story of Miami-based friends Efraim Diveroli and David Packouz who took advantage of a little-known government initiative that allowed small businesses to bid on US military contracts.
They did so successfully during the Iraq War, landing a $300 million contract to supply weapons to Afghan armed forces, who were allies of the United States.
The story originally came to light in 2011 via a Rolling Stone article and it was later made into a book. Jonah told Entertainment Weekly that he actually tried to purchase the right to the movie several years ago after reading the article, but he soon found out that director Todd Phillips beat him to the punch.
He said, "I reached out to [Todd] and said, 'If you ever make a movie out of this, I'd love to talk about playing Efraim because he is one bizarre, messed-up character."