Originally rated "R" in the U.S. upon its release, some profanity and drug use was cut from the film to be re-rated "PG". The "R" rated version was released on video but is now out of print and extremely rare.
The film was banned in June 1971 by the BBFC, before being released with an 'X' rating in November 1974. A cut version, short of 57 seconds, was passed with an '18' rating on New Year's Eve 1987 for video release. In April 2002, however, a version of the film was passed with an '18' rating by the BBFC, and all it's previous cuts were waived.