Recreational drug use

In Hamburg, The Beatles used "prellies" (Preludin) both recreationally and to maintain their energy through all-night performances.^[110] McCartney would usually take one, but Lennon would often take four or five.^[110] Bob Dylan introduced them to cannabis during a 1964 visit to New York.^[111] McCartney remembered them all getting "very high" and giggling.^[112] The Beatles occasionally smoked a joint in the car on the way to the studio during the filming of Help!, which often made them forget their lines.^[113]

In April 1965, Lennon and Harrison were introduced to LSD by an acquaintance, dentist John Riley, who slipped some into their coffees.^[114] Lennon in particular became an avid "tripper", claiming in a 1970 interview in Rolling Stone to have taken LSD hundreds of times. McCartney was more reluctant to try the drug, but finally did so in 1966 and was the first Beatle to talk about it in the press, saying in June 1967 that he took it four times.

The Beatles added their names to an advertisement in The Times, on 24 July 1967, which asked for the legalisation of cannabis, the release of all prisoners imprisoned because of possession, and research into marijuana's medical uses. The advertisement was sponsored by a group called Soma, and was signed by 65 people, including Brian Epstein, Graham Greene, R.D. Laing, 15 doctors, and two MPs.