| 1 mm with placebo administration which the authors hypothesized could hamper implantation | Taken together, these data are highly supportive of the concept that levonorgestrel emergency contraception has little or no effect on postovulation events but is highly effective when taken before ovulation |
|---|---|
| 5 mg is not known | Emergency contraceptive pills are not effective if a woman is already pregnant |
"Plan B and the politics of doubt commentary ".
9| 5 mg dose of levonorgestrel when used within 72 h after sexual intercourse and even between 72 h and 120h | J Fam Plann Reprod Health Care |
|---|---|
| Drugs for human use; drug efficacy study; amended notice" | "Plan B and the politics of doubt" |
Another study found that UPA altered the endometrium, but whether this change would inhibit implantation is unknown.
29| The primary mechanism of action is to stop or disrupt ovulation; LNG ECP use may also prevent the sperm and egg from meeting | Use as postcoital contraceptive; patient labeling" |
|---|---|
| ; Levine, Marc; Soon, Judith A | , multiple sexual partners or a rape victim |
123: Combined emergency contraceptive pills.
15