By Annette Choi and Will Mullery, CNN

(CNN) -- A federal judge in Texas ruled on Friday to suspend the Food and Drug Administration's approval of mifepristone, the first drug in the medication abortion process, nationwide by the end of this week.

The judge sided with the coalition of anti-abortion national medical associations that filed the lawsuit. He argued that the FDA failed to adequately consider risks associated with the drug, including "the intense psychological trauma and post-traumatic stress women often experience from chemical abortion."

However, data analyzed by CNN shows mifepristone is even safer than some common, low-risk prescription drugs, including penicillin and Viagra. There were five deaths associated with mifepristone use for every 1 million people in the US who have used the drug since its approval in 2000, according to the US Food and Drug Administration as of last summer. That's a death rate of 0.0005%.

Comparatively, the risk of death by penicillin — a common antibiotic used to treat bacterial infections like pneumonia — is four times greater than it is for mifepristone, according to a study on life-threatening allergic reactions. Risk of death by taking Viagra — used to treat erectile dysfunction — is nearly 10 times greater, according to a study cited in the amicus brief filed by the FDA.

"[Mifepristone] has been used for over 20 years by over five million people with the capacity to become pregnant," said Ushma Upadhyay, an associate professor in the department of obstetrics, gynecology and reproductive science at the University of California, San Francisco. "Its safety is very well established."

The Justice Department, the FDA, and Danco — a manufacturer of mifepristone that intervened in the case — have already appealed the ruling.

Within hours of the decision in Texas, a federal judge in Washington state issued a conflicting ruling that the federal government must keep mifepristone available in the 17 Democrat-led states and the District of Columbia that had sued in a separate lawsuit.

If the Texas ruling is allowed to take effect this week, 40 million more women of reproductive age would lose access to medication abortion care around the country, according to data from abortion rights advocacy group NARAL Pro-Choice America. That's in addition to the 24.5 million women of reproductive age living in states with abortion bans.

"The court's disregard for well-established scientific facts in favor of speculative allegations and ideological assertions will cause harm to our patients and undermines the health of the nation," said Dr. Jack Resneck, Jr., president of the American Medical Association, in a statement. "By rejecting medical facts, the court has intruded into the exam room and has intervened in decisions that belong to patients and physicians."

Weighing medication abortion against the alternatives

Medication abortion has become the most common method for abortion, accounting for more than half of all US abortions in 2020, according to the Guttmacher Institute.

The growing popularity of medication abortion is largely because of its accessibility, said Abigail Aiken, associate professor at the University of Texas at Austin who leads a research group on medication abortion.

"It reduces the cost, it reduces barriers where people may not want to go to a clinic," she said.

It is also a safer option than both procedural abortion or childbirth. The rate of major complications — like hemorrhages or infections — for medication abortions is about one-third of a percent, according to a 2015 study conducted by Upadhyay. That means out of more than 11,000 cases, 35 experienced any major complications.

The likelihood of serious complications via procedural abortion — performed second-trimester or later — is slightly higher than medication abortion at 0.41%, according to the same study. And childbirth by far comes with the highest risk, at 1.3%.

If access to mifepristone is cut off, abortion clinics and telehealth organizations could pivot to misoprostol-only abortions, Aiken told CNN. Although misoprostol-only abortions are used around the world, they are less effective, associated with a higher risk of serious complications and often more painful than the mifepristone and misoprostol combination, she said.

In the latest study of self-managed misoprostol-only medication abortions in the US, Johnson found misoprostol-only abortions to be a safe alternative, though less safe than using both pills. The study, published in February, analyzed data from online telehealth medication abortion provider Aid Access from 2020. Nearly 90% of 568 users reported completed abortions and 2% experienced serious complications using only misoprostol.

Mifepristone and misoprostol together is still considered the gold standard, Aiken told CNN. People who used the two-pill combination were less likely to experience serious complications than those who went with the misoprostol-only regimen.

"It's clear people can use these medications, mifepristone and misoprostol, at home even without the help of a medical professional very safely," said Aiken.

Because misoprostol is used to treat multiple ailments including stomach ulcers, it's readily stocked in pharmacies and unlikely to be taken off the market anytime soon, Johnson told CNN.

However, a lesser-effective method means more people will likely have unsuccessful abortions.

"It's possible that it might not work for some people, and it will prolong their abortions," said Upadhyay. "Then by the time they get back to the clinic, they're seeking abortion later in pregnancy."

Before the ruling, 19 states already restricted telehealth abortion care, limiting access to medication abortion. Nearly half of US adults were unsure whether medication abortion was currently legal in their state as of late-January, according to a survey conducted by the Kaiser Family Foundation. Experts say that confusion will only be exacerbated.

"People are not going to be sure mifepristone or misoprostol in fact, is available. I think it's going to be confusing," said Aiken. "As people look around for options or feel unsure about their options, they may end up delaying [care]."