As the question of mifepristone’s availability in the U.S. is fought out in federal courts, states and health care providers are looking to the only other abortion pill approved for use here and the impacts that relying on it would have on the reproductive landscape.

In most cases of medical abortions, a drug called misoprostol is taken soon after mifepristone is administered. This two-drug regimen has become the standard throughout the U.S., and studies have found it to be highly safe and effective.

As anxieties over mifepristone’s accessibility rise amid a conservative challenge to its federal approval, states including New York and California have begun stockpiling supplies of misoprostol in order to ensure access to medical abortions, which account for half of all abortions in the country.

New York Gov. Kathy Hochul (D) announced the purchase of five years’ worth of misoprostol this week, while California Gov. Gavin Newsom (D) said his state had secured 2 million pills following the initial ruling to block mifepristone’s authorization.

Hochul said this week that she also is working on legislation that would require private insurers to cover the drug when it is used for abortions. California previously passed a bill that requires insurers to cover abortion services at no-cost, including medication abortions.

What is misoprostol? Why is it paired with mifepristone?

The two drugs normally used for medical abortions in the U.S. have separate effects on a pregnant body, and the combination of both is highly effective at terminating pregnancies. 

One 2015 study of more than 13,000 women found that the two-drug course was nearly 98 percent effective and had an infection rate of only .01 percent.

Mifepristone blocks the hormone progesterone, which is needed for pregnancies to continue. After progesterone is blocked, the lining of the uterus breaks down and the pregnancy fails.

Misoprostol is then taken up to 48 hours afterwards. It causes the uterus to empty itself by causing cramping and bleeding.

In the absence of mifepristone, providers would likely turn to prescribing higher doses of misoprostol on its own. This course of treatment is more common internationally than in the U.S., but providers have already begun to consider this route in light of the recent court battle.

“We certainly are thinking about misoprostol-only regimens,” Gopika Krishna, a board-certified OB/GYN and fellow with the Physicians for Reproductive Health advocacy group, told The Hill.

“Misoprostol-only regimens are also a safe and effective way to manage an abortion through medication,” Krishna said. “It’s a regimen that we certainly are prepared to utilize.”

Not an exact replacement

While misoprostol is considered to be highly safe and effective, switching over to a one-drug regimen for medical abortions would still present challenges and represent a possible drop in ideal medical outcomes.

The Society of Family Planning (SFP) said in a report last month that misoprostol-only abortions are between 80 and 100 percent effective at terminating pregnancies, a small but significant difference from a two-drug plan, which has consistently been found to have a near 100 percent efficacy rate.

Along with a slightly lower rate of effectiveness, the side effects associated with misoprostol-only abortions would persist longer due to the higher doses. These effects can include nausea, abdominal pain, diarrhea, fever and chills.

“The addition of mifepristone allows us usually to use fewer doses of misoprostol. It can allow the procedure to be completed in a faster way as well,” Krishna said. “Generally, it can be a slightly longer process and maybe a slightly more uncomfortable process for patients.”

Could misoprostol also be on the chopping block?

Unlike mifepristone, which is authorized by the Food and Drug Administration (FDA) to terminate pregnancies, misoprostol’s use in medical abortions is considered to be off-label.

Misoprostol is approved to treat gastric ulcers in women but is commonly used by clinicians to manage miscarriages and to induce labor.

The drug is not a part of the ongoing legal furor and is expected to remain available regardless of how courts rule on mifepristone.

The lack of official approval as an abortifacient leaves it unclear whether anti-abortion activists have a legal avenue to stop misoprostol from being used in medical abortions.

Where it stands now

The 5th Circuit Court of Appeals ruled this week that mifepristone’s authorization could not be challenged, given how long it’s been on the market, and allowed the drug to remain available, albeit with some added limitations.  

The court rolled back expansions to medical abortion access the federal government had made post-2016, cutting the 10-week limit to take the drugs down to seven weeks and blocking the ability to mails the medications.

However, the Supreme Court on Friday paused the limitations enacted by the lower court, maintaining the status quo of mifepristone’s availability.

The two-drug treatment should still be accessible to most women for the time being, though mifepristone’s status could also still get revoked. The Supreme Court could send the case back down to the conservative led Fifth Circuit Court.

The order to maintain the status quo will remain in effect until midnight on Wednesday.

“We are pleased that the court took the only sensible action here, which was to hit pause on a profoundly dangerous decision that has been widely criticized as unprecedented and wholly unprincipled by experts across the ideological spectrum,” the American Civil Liberties Union said in a Friday statement.

“Today’s ruling is just the first step: Now the courts must put an end to this baseless case — which is part of anti-abortion extremists’ plan to ban abortion nationwide. It threatens access not only to abortion and miscarriage care, but also to a wide swath of critical and life-saving medications. No matter what happens next, we know this fight is far from over.”