A Missouri judge ruled Friday that a ban on gender-affirming health care for minors can take effect on Monday, as scheduled.

The ruling by St. Louis Circuit Judge Steven Ohmer means that beginning next week, health care providers are prohibited from providing gender-affirming surgeries to children. Minors who began puberty blockers or hormones before Monday will be allowed to continue on those medications, but other minors won’t have access to those drugs.

Some adults will also lose access to gender-affirming care. Medicaid no longer will cover treatments for adults, and the state will not provide those surgeries to prisoners.

Physicians who violate the law face having their licenses revoked and being sued by patients. The law makes it easier for former patients to sue, giving them 15 years to go to court and promising at least $500,000 in damages if they succeed.

The ACLU of Missouri, Lambda Legal, and Bryan Cave Leighton Paisner last month sued to overturn the law on behalf of doctors, LGBTQ+ organizations, and three families of transgender minors, arguing that it is discriminatory. They asked that the law be temporarily blocked as the court challenge against it plays out. The next hearing in the case is scheduled for Sept. 22.

But Ohmer wrote that the plaintiffs’ arguments were “unpersuasive and not likely to succeed.”

“The science and medical evidence is conflicting and unclear. Accordingly, the evidence raises more questions than answers,” Ohmer wrote in his ruling. “As a result, it has not clearly been shown with sufficient possibility of success on the merits to justify the grant of a preliminary injunction.”

One plaintiff, a 10-year-old transgender boy, has not yet started puberty and consequently has not yet started taking puberty blockers. His family is worried he will begin puberty after the law takes effect, meaning he will not be grandfathered in and will not have access to puberty blockers for the next four years until the law sunsets.

The law expires in August 2027.

Proponents of the law argued that gender-affirming medical treatments are unsafe and untested.

Republican Attorney General Andrew Bailey’s office wrote in a court brief that blocking the law “would open the gate to interventions that a growing international consensus has said may be extraordinarily damaging.”

The office cited restrictions on gender-affirming treatments for minors in countries including England and Norway, although those nations have not enacted outright bans.

An Associated Press email requesting comment from the Attorney General’s Office was not immediately returned Friday.

Every major medical organization in the U.S., including the American Medical Association, has opposed bans on gender-affirming care for minors and supported the medical care for youth when administered appropriately. Lawsuits have been filed in several states where bans have been enacted this year.

“We will work with patients to get the care they need in Missouri, or, in Illinois, where gender-affirming care is protected under state law,” Yamelsie Rodríguez, president and CEO, Planned Parenthood of the St. Louis Region and Southwest Missouri, said in a statement after the ruling.

The Food and Drug Administration approved puberty blockers 30 years ago to treat children with precocious puberty — a condition that causes sexual development to begin much earlier than usual. Sex hormones — synthetic forms of estrogen and testosterone — were approved decades ago to treat hormone disorders and for birth control.

The FDA has not approved the medications specifically to treat gender-questioning youth. But they have been used for many years for that purpose “off label,” a common and accepted practice for many medical conditions. Doctors who treat trans patients say those decades of use are proof the treatments are not experimental.