Britain is to ban indefinitely the use of puberty blockers for young people under 18 with gender dysphoria, except in clinical trials, the government said on Wednesday, making permanent a set of temporary restrictions put in place earlier this year.

Announcing the decision, Wes Streeting, the health secretary, said he was acting after having received advice from medical experts, who concluded that there was an unacceptable safety risk in prescribing puberty blockers without further research into their impact.

“We need to act with caution and care when it comes to this vulnerable group of young people, and follow the expert advice,” Mr. Streeting said in a statement.

He added: “We are setting up a clinical trial into the use of puberty blockers next year, to establish a clear evidence base for the use of this medicine.”

The move follows steps taken by the previous Conservative government to restrict the use of such drugs , including prescribing hormones to pause puberty or to change physical characteristics.

The country’s National Health Service stopped the routine prescription of puberty blocker treatments to anyone under 18 as treatment for gender dysphoria following a landmark review into gender identity services undertaken by Hilary Cass, one of the country’s top pediatricians.

Her report, published in April, concluded that gender medicine was operating on “shaky foundations” when it came to the evidence for some medical treatments.

Puberty blockers were banned temporarily for the treatment of gender dysphoria in those under 18 in May.

New York Times News Service