Rt Rev Paul Mason said “vulnerable children should not be part of an experiment of the kind that will soon be starting at King’s College.”
Puberty blockers are drugs used to delay or prevent puberty. In December, the Health Secretary Wes Streeting banned their prescription to young patients unless they are on a clinical trial. The trial, which is due to start at King's College London this month, will involve children as young as 11, who are being seen at gender clinics in England.
The research team says their physical and mental health will be closely monitored and there will be a careful consent process involving children and their parents.
Streeting told MPs he was "uncomfortable" about puberty blockers being used on young people but said he had given the go-ahead for the trial because he felt it was the "right thing to do" after it was recommended by a review into children's gender care.
However, the CEO of Sex Matters Maya Forstater wrote to the Health Secretary in November saying the trial was "being pushed ahead despite methodological, legal and ethical concerns. The care of children continues to be led by ideology rather than by an approach focused on children’s best interests."
In his statement, Bishop Paul said: “I would like to add my concerns to those of many others who have spoken out about the proposed clinical trial at King’s College London...
“I recognise the profound difficulties faced by young people and their families as a result of conditions such as gender dysphoria. However, we should offer support to these children rather than following a path where the natural process of puberty is blocked....It is important that medical science progresses in the hope of providing better care to people affected by serious conditions. However, strong ethical boundaries must govern all experimentation and medical treatment."
Calling on the government and the university’s research ethics committee to halt the trial, he added that there is a lack of "sufficient knowledge of long-term outcomes to justify exposing more children to these drugs."