How Plan B One-Step® Works
There are many misconceptions about emergency contraception, so it's important for women to know that Plan B One-Step® works similarly to regular birth control pills; it simply contains a larger dose of the hormone levonorgestrel. Plan B One-Step® works primarily by:
- Preventing ovulation
It may also work by:
- Possibly preventing fertilization by altering tubal transport of sperm and/or egg
- Altering the endometrium, which may inhibit implantation
Plan B One-Step® should not be taken as routine birth control as it is not as effective. Plan B One-Step® should be taken as soon as possible within
72 hours (3 days) of contraceptive failure or unprotected sex. When taken as directed, nearly 7 out of 8 expected pregnancies were prevented.
Plan B One-Step® is not effective once the process of implantation has begun.
It will not harm an existing pregnancy.