Only purchase Levonelle One Step online as a standby in case of a contraceptive failure. If you have already had unprotected sex, go to your local Pharmacy, GP, Family Planning Clinic, or Emergency Out of Hours Service. Levonelle one step is an emergency contraceptive. It can help to protect you from getting pregnant, but you must take the tablet within 72 hours of having unprotected sex. The pack holds a complete course of one tablet containing 1500 micrograms. The tablet also contains lactose. Directions: Take the tablet as soon as possible (but no later than 72 hours) after you have had unprotected sex.