Advice for The Morning After Pill
The morning after pill works primarily by delaying ovulation, so sperm cannot fertilise an egg.
- Levonorgestrel-based pills (Levonelle) contain a synthetic version of progestogen, which prevents or delays the release of an egg. It is most effective within 24 hours, but can be taken up to 3 days (72 hours) after sex.
- Ulipristal acetate pills (EllaOne) work by blocking progesterone, which delays ovulation more effectively than levonorgestrel, even when taken closer to ovulation. It remains effective up to 5 days (120 hours) after sex.
The morning after pill does not work if ovulation has already occurred, and it does not protect against future unprotected sex.
The morning after pill works primarily by delaying ovulation, so sperm cannot fertilise an egg.
- Levonorgestrel-based pills (Levonelle) contain a synthetic version of progestogen, which prevents or delays the release of an egg. It is most effective within 24 hours, but can be taken up to 3 days (72 hours) after sex.
- Ulipristal acetate pills (EllaOne) work by blocking progesterone, which delays ovulation more effectively than levonorgestrel, even when taken closer to ovulation. It remains effective up to 5 days (120 hours) after sex.
The morning after pill does not work if ovulation has already occurred, and it does not protect against future unprotected sex.

