LONDON — The publicly funded health service in England has decided it will not routinely offer puberty-blocking drugs to children at gender identity clinics, saying more evidence is needed about the potential benefits and harms.

The National Health Service said Friday that “outside of a research setting, puberty suppressing hormones should not be routinely commissioned for children and adolescents.”

Children can still be given puberty blockers in exceptional circumstances, the NHS said, and a clinical study on their impact on tots is due to start by next year.

The four new regional clinics are due to open later this year. They replace London’s Gender Identity Development Service, previously the only facility of its kind in England. It is scheduled to shut down after a review said it was overburdened by increasing demand and there was not enough evidence about the outcomes of its treatment.

Hormone blockers are drugs that can pause the development of puberty, and are sometimes prescribed to help children with gender dysphoria by giving them more time to consider their options.

The NHS said the new rules were “an interim policy” that would undergo further review, including the outcome of a research study on the impact puberty suppressing hormones have on gender dysphoria in children and young people.

Findings published last year from a review of children’s gender services led by a pediatrician, Dr. Hilary Cass, said there were “gaps in the evidence base” about the blockers.

The NHS said doctors at the new clinics still would be allowed to prescribe the drugs outside of a research setting “on an exceptional, case by case basis” and subject to approval from a national team of medical experts.

The health service’s decision does not prevent children and their families from obtaining puberty blockers elsewhere, but that will be “strongly discouraged,” the NHS said.

The issue of what is called “gender-affirming care” for children is not as heated in Britain as in America, where several Republican-led states have banned puberty blockers and other treatment for transgender minors, but it has ended up in the courts.

In 2020, England’s High Court ruled that children under 16 were unlikely to be able to give informed consent to medical treatment involving drugs that delay puberty. The court said that because of the experimental nature of the drugs, clinics should seek court authorization before starting such treatment.

The ruling came in a lawsuit brought by two claimants. One, Keira Bell, who was prescribed hormone blockers at 16, argued that the clinic should have challenged her more over her decision to transition to male.

The decision was overturned in 2021 by the Court of Appeal, which said doctors can prescribe puberty-blocking drugs to children under 16 without a parent’s consent.

The NHS said it recognized that once the policy was adopted, it would need to end a related requirement for young people to take puberty blockers for a certain amount of time before they receive the cross-sex hormones many transgender people take to transition.

Associated Press