By Brendan Pierson

Colorado cannot stop a Catholic medical center from offering an unproven treatment meant to reverse the effects of pill used in medication abortion, a federal judge has ruled.

U.S. District Judge Daniel Domenico said in an opinion on Saturday that a Colorado law banning so-called medication abortion reversal treatment likely violates the U.S. Constitution's guarantee of religious freedom. His order stops the state from enforcing the law against Bella Health and Wellness, which sued to block it, or against anyone else working with Bella Health, while he considers the medical center's challenge to the law.

"We are relieved and overjoyed to continue helping the many women who come to our clinic seeking help," said Dede Chism and Abby Sinnett, cofounders of the Catholic medical center located in Englewood just outside of Denver.

The office of Colorado Attorney General Phil Weiser, which defended the law, declined to comment.

Medication abortion begins with the drug mifepristone, which blocks the action of the hormone progesterone, crucial for sustaining pregnancy, and is completed with a second drug, misoprostol. Proponents of the so-called medication abortion reversal say that if a woman changes her mind after taking mifepristone but before taking misoprostol, the pregnancy can be continued by administering a high dose of progesterone.

There are no large controlled studies of the treatment, and the American College of Obstetricians and Gynecologists has said that its safety and efficacy are unsupported by science.

Colorado Governor Jared Polis, a Democrat, signed a law on April 14 that would subject health care practitioners who perform medication abortion reversal to discipline. Bella filed its lawsuit the same day the law was signed.

Domenico, who was appointed by Republican former president Donald Trump, said the law likely violated Bella Health's religious freedom because it treated the use of progesterone for medication abortion reversal differently from other uses of the hormone.

The abortion pill has been the subject of multiple lawsuits. Anti-abortion groups earlier this year won an order essentially banning it, though that order is on hold while the Biden administration appeals to the U.S. Supreme Court.

Republican state legislatures have also taken steps to restrict access to the drug, while Democratic legislatures have sought to protect it.

Meanwhile, CVS Corp last week pulled certain cold medicines from shelves after U.S. regulators said their active ingredient, phenylephrine, was not supported by evidence.

(Reporting By Brendan Pierson in New York, Editing by Alexia Garamfalvi and Aurora Ellis)