Alison HoltSocial affairs editor
BBCCampaigner Keira Bell has told the BBC she believes the planned clinical trial of puberty blocking drugs for gender-questioning children is unethical and children “are essentially going to be harmed”.
The Pathways trial, run by King’s College London researchers, will look at how to improve care for children under 16 at NHS gender clinics.
The UK medicines’ regulator has approved the study to begin in January, and the research team says it has been designed “to meet rigorous scientific and ethics standards”.
Ms Bell and fellow campaigner, psychotherapist James Esses, have sent lawyers’ letters to Health Secretary Wes Streeting and medical research organisations arguing it should be stopped.
The threatened legal action questions the safety and transparency of the clinical trial, if it is necessary, and whether it meets the expected “ethical principles”.
The government says the trial will provide evidence that is lacking about the risks and benefits of the drugs, and that there are multiple safeguards in place to protect young people.
Puberty blockers, also known as puberty suppressing hormones (PSH), are drugs used to delay or prevent puberty happening.
They are used to treat some children and young people with gender incongruence – when someone’s gender identity doesn’t match the sex they were registered at birth – or with gender dysphoria, when it causes significant distress.
The drugs were banned in the UK for gender treatment last year after a major review raised concerns about the lack of clinical evidence over their safety for under-18s.
The same review, carried out by paediatrician Dr Hilary Cass, said a clinical trial was necessary to provide solid evidence as to whether or not the drugs were beneficial.
Dr Cass recently told the BBC she was “really pleased” the KCL team was carrying out the trial.
The study will examine the physical and emotional effects of puberty blockers on about 220 children under the age of 16 attending NHS gender clinics in England, with strict criteria having to be met for any child taking part.
The children will be provided with intensive support. Researchers say they will also monitor bone density and brain development.
Keira Bell was given puberty blockers and cross-sex hormones as a teenager. She regrets that and believes she should have been challenged more by staff at the Tavistock Gender Identity Clinic, which is now closed.
In 2020, she took legal action against the clinic. The High Court ruled that under-16s were “unlikely to be able to give informed consent” to puberty blockers, but this was later overturned by the Court of Appeal, which ruled that doctors can judge whether young people can give consent to the treatment.
Ms Bell, 28, told the BBC: “Children are essentially going to be harmed from this trial.”
She said children’s fertility and sexual function could be affected.
Her own experience of taking puberty blockers has left her “extremely angry”, she added.
“I didn’t know that I was essentially trapping my own mind from developing, because puberty doesn’t happen in a vacuum – it’s your whole body, it’s your brain sending signals to your body. So I didn’t understand any of that,” she said.
“There are children who have already been down this pathway – I’m one of them. Why aren’t we doing follow-ups with people like me?”
James Esses told the BBC there were questions around informed consent.
“Some of the children who are going to be taking part in this trial are not even old enough to open a current account or open a Facebook profile,” he said.

Legal letters from the campaigners have been delivered to the Human Research Authority (HRA) and the Medicines and Healthcare products Regulatory Authority (MHRA), which have given the puberty blockers trial ethical approval.
Mr Streeting, along with NHS England, King’s College London and the South West London and Maudsley NHS Trust have also been notified.
A Department of Health and Social Care spokesperson said medical care “must always be based on solid evidence, and children’s safety must come first”.
They added: “This trial will help provide the evidence that is currently lacking. Its approval came only after extremely rigorous safety checks and with multiple safeguards in place to protect young people’s wellbeing – including clinical and parental approval.”
In a statement, the MHRA said the safety of participants was “always” its priority and its role was to “rigorously assess” clinical trial submissions to ensure they met “the appropriate regulatory standards of participant safety and scientific integrity”.
It said it also continually reviews the approval of the trial as it proceeds.
A spokesperson for the Health Research Authority, said the Pathways trial had “all the necessary regulatory approvals that it needs to begin”.
It explained that a Research Ethics Committee, made up of people including healthcare professionals and members of the public, look at research proposals and give opinions about whether they are ethical.
The KCL research team said: “Clinical care should always be underpinned by robust evidence, and this study will help provide a better understanding of how to treat and care for young people with gender incongruence.”
The researchers said children taking part in the study would need the consent of their parent or legal guardian, plus the agreement of their lead clinician and a multidisciplinary team.
A spokesperson for charity Stonewall said it was “vitally important” that all LGBTQ+ people, including young people, have access to high-quality, evidence-based and timely healthcare.



