"People often think unplanned pregnancies are [the consequence of] people being irresponsible, but that's not [usually] the case. It's often from a failed attempt at contraception -- that's why it's so important that we have emergency contraception."
Streicher says the longer window for taking ellaOne fills a much-needed gap in reproductive health because those who most often have unwanted pregnancies -- teenagers, those without access to adequate gynelogical care -- cannot always get to a doctor for treatment within a day or two.
"In a perfect world you want anyone to use emergency contraception within 24 hours, but the reality is that having this five-day option is going to decrease the number of undesired pregnancies," she said.
But this more powerful form of emergency contraception raises several concerns for pro-life advocates.
Harrison says that unlike Plan B, ellaOne acts is chemically similar to the common abortion pill RU-486, which is taken to abort a fetus as late as two months into pregnancy.
She feels that ellaOne is likely to carry the same risks as RU-486, such as excessive bleeding and infection, and says her biggest concern is risks this new drug could pose to the women who take it.
Harrison cites one Plan B study, in which more than half the women who participated didn't know how to use the pill correctly. It is currently available over-the-counter.
Given that ellaOne would also be available over the counter if it was brought to the U.S. as an emergency contraceptive, Harrison fears the chance for misuse and adverse side effects.
"That's the purpose, to slip an abortive agent into the country as an over-the-counter drug. It's deceitful."
In the recent Lancet study, however, the only serious adverse event researchers found with ellaOne was dizziness, and this only occurred in one subject.
Another concern among critics of the drug is the fear that it will give women a sense of false security, leading them to be more lax about using contraception or practicing abstinence.
"Habits follow technology. Contraception was supposed to prevent an abortion, but it has led to an increase in abortion when people got used to it being around and of course the increased effectiveness of technology [like this] means people will relax that much more on their inhibitions," said Stephen Phelan, communications manager for Human Life International, an anti-abortion missionary organization.
But Streicher countered that in her twenty years of experience, and in the literature on the topic, this fear is unfounded.
"Emergency contraception does not increase the chance that someone is going to not use contraception or that someone is going to start sexual activity at an earlier age. On the contrary, it is necessary option for women who have that rare contraception failure or...even more importantly, for those who are raped."
According to HRA Pharma, the company that produces the drug, elleOne was made in the hope of providing "the potential to enable women to take greater control of their own health." The statement came from Dr. Erin Gainer, CEO of HRA Pharma, in a company press release.