Suppositories generally take between 15 minutes to 1 hour to work. Rectal suppositories like glycerin and bisacodyl usually start to take effect within this time frame, with some types like carbon dioxide-releasing suppositories working within 15 to 30 minutes. Vaginal suppositories typically take about 15 to 30 minutes to dissolve and be absorbed into the body. It is recommended to hold the suppository in place for about 15 to 30 minutes to allow it to dissolve and release medication properly.