Oppenheimer: Why Cillian Murphy Wants To Quit Smoking Onscreen

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Herbal cigarettes may not be full of poison, but they're not exactly health boosters either.

Cillian Murphy won't be quitting the world of acting anytime soon. But what he has decided to quit — at least for a while — is the act of fake smoking.

Recently catching up with The Guardian, Murphy confessed that his time playing Birmingham gang leader Thomas Shelby (Peaky Blinders) and Manhattan Project physicist J. Robert Oppenheimer (Christopher Nolan's Oppenheimer) gave him enough faux tobacco for a lifetime. While prop cigarettes don't contain the harmful and known carcinogenic ingredients found in the real thing, they're not exactly health boosters either, per the National Library of Medicine.

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"My next character will not be a smoker," the actor declared. "They can’t be good for you. Even herbal cigarettes have health warnings now."

Nevertheless, feigning the existence of a lifelong nicotine addict was absolutely essential to playing Doctor Oppenheimer, who was almost aways seen with a cigarette or pipe in his hand. "He would alternate between the two. That’s what did for him in the end,” Murphy explained, alluding to the fact that the real Oppenheimer died of throat cancer at the age of 62 in early 1967.

Written, directed, and produced by Nolan, the atomic bomb thriller tracks the development, creation, and aftermath of America's race to split the atom ahead of the Nazis and bring a swift end to the Second World War.

Oppenheimer proved instrumental in the project's success, though he ultimately came to regret his involvement and was blacklisted as a result. His famous quote upon witnessing the first atomic blast — "Now I am become Death, the destroyer of worlds" — denoted the existential horror he felt at placing such an awesome power into the hands of a species known for waging one conflict after another. And he was correct to give voice to such dread as the threat of nuclear annihilation came to define the entire second half of the 20th century.

WATCH NBC WEB EXCLUSIVE: "It Feels Very Intimate:" Cillian Murphy on Working with Christopher Nolan and His Prep for Oppenheimer

"He was dancing between the raindrops morally," Murphy added. "He was complex, contradictory, polymathic; incredibly attractive intellectually and charismatic, but ultimately unknowable."

Oppenheimer arrives exclusively in theaters next Friday — July 21. Click here to pick up tickets and click here to check out the first explosive reactions to the film. The early critical reaction to the film has been nothing short of amazing, with many saying it could be Nolan's greatest work yet.

Want more blockbuster thrills in the meantime? Jaws, Jurassic Park, The Da Vinci Code, The Hunger Games, Fast Five, Jurassic World, Knock at the Cabin, Cocaine Bear, Renfield, and more are now streaming on Peacock!