Doctors in England can no longer prescribe puberty blockers to children to facilitate a gender transition, according to an announcement from the country’s public health-care system, the National Health Service (NHS).

“Puberty blockers … are not available to children and young people for gender incongruence or gender dysphoria because there is not enough evidence of safety and clinical effectiveness,” the NHS England website’s section on “treatment” for gender dysphoria reads after the update.

The drugs block a child’s natural developments during puberty by preventing the production of hormones, such as testosterone and estrogen. For example, they prevent height growth, a girl’s breast development, and a boy’s facial hair growth, among other things.

“Children, young people, and their families are strongly discouraged from getting puberty blockers or gender-affirming hormones from unregulated sources or online providers that are not regulated by U.K. regulatory bodies,” the website’s text reads.

More than half of the states in the United States still allow doctors to prescribe puberty blockers to children.

This is a developing story.