With Governor Rick Perry signing the restrictive Texas abortion bill into law many news organizations have shed light on traveling to Mexico for abortion and there has been much talk about the “Mexican abortion pill.”

The medication that people typically call the Mexican abortion pill is misoprostol, marketed under the trade name Cytotec. It is a prostaglandin analogue and is used for prevention of stomach ulcers. It also has many uses in OB/GYN such as inducing labor, preparing the cervix for a therapeutic abortion, treating a missed abortion (a miscarriage where the pregnancy ends, but the uterus fails to empty), and as part of the two drug regimen for medical termination of pregnancy (medical abortion).

With medical abortion the most effective regimen is 200 mg of oral mifepristone (RU-486) followed by 800 mcg of misoprostol given vaginally 6-24 hours later. This regimen is 95-99% effective at terminating a pregnancy up to 63 days gestational age (9 weeks) with an extremely low rate of serious complications.

Studies have also looked at misoprostol alone and it is fairly effective. When 800 mcg of misoprostol is moistened with water and used vaginal and repeated every 24 hours (up to 3 doses) the success rate is 88% for terminating pregnancies up to 56 days gestation (8 weeks). You might say, “Well, 88% isn’t bad!” but that is significantly less effective than the mifepristone-misoprostol combination.

How safe is a misoprostol only regimen? It’s not inherently unsafe or dangerous if supervised, but therein lies the issue. If a woman is driving across the border to get the tablets it isn’t a stretch to say that she is unsupervised and hasn’t been adequately screened.

If a woman is further along than she thinks and uses the misoprostol only regimen she could have catastrophically heavy bleeding and not know when to call for help. In addition, about 1% of women who use this method appropriately will bleed enough they need expert intervention. A woman who got her medications from Mexico may feel too much stigma or may be medically disadvantaged enough to get appropriate help.

Inadequate screening may also lead a woman with an undiagnosed ectopic pregnancy to use misoprostol with devastating complications. Other issues surround the failure rate. If the pregnancy fails to abort and a surgical termination isn’t possible (this will happen for at least 12% of women, but likely more because many women who resort to getting misoprostol in Mexico will likely be further along than 56 days), the pregnancies that continue may be at increased risk of birth defects.

According to the American Congress of Obstetricians and Gynecologists (ACOG) mifepristone/misoprostol 200 mg/800mcg is the preferred regimen.

Unless the law is overturned women in Texas needing abortion are likely to get a less effective regimen with no supervision and somehow this will make abortion “safer” for women.

Jennifer Gunter is an obstetrician-gynecologist and author of The Preemie Primer. She blogs at her self-titled site, Dr. Jen Gunter.