Limitless is a 2011 American action thriller film directed by Neil Burger and starring Bradley Cooper, Abbie Cornish, and Robert De Niro. It is based on the 2001 novel The Dark Fields by Alan Glynn with the screenplay by Leslie Dixon. The film was released in the United States and Canada on March 18, 2011. It is scheduled to be released in the United Kingdom on March 23, 2011.

Eddie Morra (Bradley Cooper) is a writer who lives in New York City and has recently been dumped by his girlfriend Lindy (Abbie Cornish) in addition to failing to meet the deadline to turn in his new book, which he hasn't written yet. One day, Eddie comes across Vernon Grant (Johnny Whitworth), the brother of his ex-wife Melissa Grant (Anna Friel). Vernon is a drug dealer who offers Eddie a sample of a new drug, NZT-48, which will make him more focused. Eddie accepts and, much to his surprise, the drug increases his intelligence and improves his focus.

Eddie asks Vernon for more of the drug, which is illegal, and Vernon agrees. When Eddie goes to Vernon's apartment, he finds Vernon dead. He also finds a stash of NZT hidden in the oven alongside a book with several names and some money, which he steals. With Vernon's money and the NZT, Eddie creates a new image for himself and abandons writing to enter the finances market. Becoming rich at an incredibly fast pace and is soon being employed by powerful businessman Carl Von Loon (Robert DeNiro). Eddie also gets back together with Lindy and starts feeling he is being stalked by a man in a tan coat (Tomas Arana). Soon, the side-effects of NZT appear: Eddie has to keep moving forward or he feels physically and mentally restless, and starts having memory lapses in which his mind appears to be oblivious to the actions of his body.

Failing to accomplish a task assigned to him by Carl because of the lack of NZT and fearing he might have killed a woman he had sex with in the night before, during one of his memory lapses, Eddie calls the names in Vernon's book and discovers that they are all dead or hospitalized because of their connection with the drug. He is chased by the Man in Tan Coat, but escape and meets Melissa, who reveals that she had also taken NZT. She reveals that withdrawal causes death or a serious damage of the mental faculties, which she is going through. Eddie is warned to reduce the dosages until he can stop, before it's too late.

Eddie tries to do so, but, with the lack of it, he starts to feel ill. With no other options, he tells Lindy everything and has her pick up some from her apartment, where he had hidden the rest of his stash. On her way back, Lindy is chased by the Man in Tan Coat, but manages to escape by taking a dose herself. Back at her apartment, Lindy gives Eddie the drugs and wishes him good luck, as she wants to have nothing to do with Eddie's situation.

Eddie pays a chemist to produce more NZT, and starts being harassed by Gennady (Andrew Howard), a Russian mobster with whom Eddie had made a deal earlier. Gennady has taken one of Eddie's pills and become addicted as well. To make things worse, he is named a suspect of the death of the woman he had sex with. To protect himself, Eddie moves to a house with reinforced security and hires a lawyer named Morris Brandt (Ned Eisenberg), who clears him of the murder charges.

One day, Eddie's house is invaded by Gennady and his men, who want the drugs. Eddie discovers that Gennady melts the pills and injects them directly into his bloodstream, so, he stabs Gennady to death with a kitchen knife and drinks his blood, which contains the substance. He uses the rush to kill the rest of Gennady's men and dispose of their bodies.

Eddie also discovers that the Man in Tan Coat works for Hank Atwood (Richard Bekins), a businessman who was planning to merge his company with Carl's, but fell ill due to NZT withdrawal before he could sign the papers. Desperate for a dose, Atwood had the Man in Tan Coat tail Eddie and frame him for the death of the woman in order to steal his stash, but Brandt, who was also working for Atwood, steals it first and keeps it for himself, causing Atwood's death. Eddie and the Man in Tan Coat make a deal and kill Brandt, allowing Eddie to retrieve his stash.

12 months later, Eddie has published his book and become a Senator, with a chance to run for President of the United States of America. One day, he is approached by Carl, who reveals that he has bought the pharmaceutical company that created NZT and destroyed all labs of it, including Eddie's. In exchange for a unlimited supply of the substance, Eddie is to push forward Carl's agendas. However, Eddie reveals that he had his team reverse-engineer the NZT, creating a permanent dose which he has taken, giving him all the benefits and none of the side-effects of the drug. With no leverage against Eddie, Carl leaves, defeated. Eddie then meets with Lindy, with whom he has married, and they have lunch together.