Co-written by Beatty and Robert Towne, the film follows a promiscuous Los Angeles hairdresser on Election Day 1968, as he juggles his relationships with several women.

On the eve of the 1968 United States presidential election, successful Beverly Hills hairdresser George Roundy meets with Felicia, one of his several clients/sexual partners, at his apartment.

During sex, he receives a phone call from Jill, his naive, younger, up-and-coming actress girlfriend, who is suffering a panic attack, paranoid that an intruder is in her home.

George's occupation and charisma have provided him the perfect platform from which to meet and have sex with beautiful women, including his current girlfriend.

Despite this, 34-year-old George is dissatisfied with his professional life; he is the creative star of the salon in which he works, but has to play second fiddle to Norman, the "nickel-and-diming" mediocre hairdresser who owns the business.

All the principals except Felicia adjourn to a posh counterculture party at a Beverly Hills mansion, where guests indulge in alcohol, other drugs, and sexual pursuits.

Pepper's Lonely Hearts Club Band" and "Lucy in the Sky with Diamonds"), Buffalo Springfield ("Mr.

Soul"), Jefferson Airplane ("Plastic Fantastic Lover" and "Good Shepherd"), and Jimi Hendrix ("Manic Depression").

Also included on the soundtrack album is "Wouldn't It Be Nice" by the Beach Boys, which plays over the opening and closing credits of the film.

[5] The guests included Warren Beatty, Andy Warhol, Salvador Dali, Amanda Lear, Sylvia Miles, John Fairchild, and Maureen Stapleton.

Upon its release, the film generally received positive reviews from critics who lauded its talented cast and sharp, satirical writing.

[3] It earned an estimated $23.9 million in North American rentals,[11] making it the third-highest-grossing film of 1975, beaten only by Jaws and One Flew Over the Cuckoo's Nest.

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".