Compare to the active ingredient in Plan B One-Step. It’s a new day in America. For that, there is PostDay One-Step. PostDay One-Step is a recognized and trusted brand around the globe. Emergency contraception that temporarily delays ovulation. PostDay One-Step temporarily delays the release of an egg to meet the sperm, there is no fertilization and no pregnancy. Emergency contraception that will not affect your future plans to get pregnant. Taking PostDay One-Step after unprotected sex now, does not hurt the ability to get pregnant in the future. NO prescription is required. LxWxH 3.5" x 0.6" x 5.0". Weight 0.12lbs.