In 1968, on the eve of the elections that will end with Richard Nixon ascending to the office of U.S. President, George Roundy is a successful Beverly Hills hairdresser, whose occupation and charisma have provided him the perfect platform from which to meet and have sex with beautiful women, including his current girlfriend, Jill, a model. Despite this, George is a 34 year old dissatisfied with his professional life; he is the creative star of the salon, but has to play second fiddle to Norman, the "nickel-and-diming" mediocre hairdresser who owns the place. George dreams of setting up his own salon business, but cannot convince any bank to loan him the capital he needs. So he turns to his lover Felicia and her wealthy unsuspecting husband Lester to bankroll him. George's meeting with Lester supplies a second secret for him to keep from his would-be benefactor, Lester's current mistress, Jackie, who is George's former girlfriend, perhaps the most serious relationship he has ever had. Lester, who assumes George is gay because of his profession, invites him to escort Jackie to a Republican Party election night soiree, at which George finds himself in the same room as a number of present and former sexual partners. The principals adjourn to a posh counterculture party, and the night quickly descends into alcohol and other drugs and sexual indulgence. Later, Lester and Jill happen upon George and Jackie having vigorous sex on a kitchen floor. Lester is stunned into silence but when Jill recognizes the writhing couple, she throws a chair at the window and swears at George; as George tries to placate Jill, Jackie flees. George chases after Jackie and proposes to her, but Jackie tells him that she has arranged to go toAcapulco with Lester, who has said he will divorce Felicia and marry her. Jackie leaves George alone on a hilltop above her house, from where he watches her leave with Lester.
Upon its release, the film generally received positive reviews from critics who lauded its talented cast and sharp, satirical writing. Praise was not universal; some critics, including Roger Ebert, pronounced it a disappointment. From reviews compiled retrospectively, review aggregation website Rotten Tomatoes gives the film a score of 60% based on 35 reviews, with an average score of 6.4/10. The site's consensus reads: "Shampoo trains a darkly comic lens on post-Nixon America, aiming at—and often hitting—an array of timely targets". Commercially, Shampoo was a great success. Produced on a budget of $4 million, the film grossed $49,407,734 domestically and $60 million at the worldwide box office. It was the fourth-most successful film of 1975 by box office takings, beaten only by Jaws, One Flew Over the Cuckoo's Nest, and The Rocky Horror Picture Show. The year after its release saw a blaxploitation send-up, Black Shampoo.
