A preliminary pharmacological trial of the monthly injectable contraceptive cycloprovera

A comparative pharmacological pilot study of the monthly injectable contraceptive CycloProvera was carried out in 11 women in four centres. There were no significant differences in the results between the centres except that the injection-bleeding interval appeared to be shorter in Swedish women than in those in Havana and Mexico. Medroxyprogesterone acetate was detectable in blood for 28 to 62 days after injection of CycloProvera and although follicular activity returned in less than 28 days after injection in many of the women, corpus luteum function was suppressed for at least seven weeks in all women. Most of the women retained a regular menstrual pattern; six of 33 cycles were amenorrhoeic. There was no significant change in any of the biochemical and haematological analyses.