The shots must be administered by a healthcare provider and women cannot go longer than 33 days between shots, or they will need a pregnancy test before the next injection. Lunelle is an alternative to another injectable contraceptive called Depo-Provera that lasts three months. Like many birth control pills, it works through a combination of the hormones progestin and estrogen. Effectively Lunelle was approved based on data from a clinical study of 1,103 women at 42 sites in the United States. The 783 women taking Lunelle had no unintended pregnancies, though there were two among the 321 women using the oral contraceptive after 15 cycles of use.
Women taking the contraceptive injection still have monthly menstrual cycles.
There also is a quick return to ovulation, usually within two to four months, Pharmacia said. More than 50 percent of users became pregnant within six months of quitting Lunelle. The Associated Press contributed to this report. The Web Copyright 2000 ABC News Internet Ventures.