Trial on Puberty Blockers to Reduce Harm, Says Cass Report Author
A clinical trial investigating the risks and benefits of puberty-delaying drugs for gender-questioning children is expected to reduce harm, according to Dr Hilary Cass, author of a significant review on the topic.
"I am absolutely convinced that more children will be harmed if we don't do the trial than if we do,"Dr Cass stated.
Her remarks come amid pressure from campaigners and some politicians to cancel the research programme after it was revealed that children as young as 11 could be enrolled in the trial.
The Pathways clinical trial will be conducted by researchers at King's College London (KCL). In addition to establishing a minimum age for participation, the researchers have enhanced safeguards for those involved.
The recommendation for this puberty blockers research originated from Dr Cass's 2024 review of gender medicine for children, which highlighted the limited evidence supporting their use.
Historically, the NHS has prescribed puberty blockers for individuals under 18 as part of gender care. However, in 2024, the government implemented a UK-wide, indefinite ban on prescribing these drugs both privately and through the NHS.
Speaking to the BBC, Dr Cass expressed her view that since the ban,
"some of the hype about risks have been exaggerated in that we genuinely don't know if there are harms."
She emphasized that the trial is
"essential"to determine
"whether these drugs are helpful or not."
Dr Cass further explained that young participants will be
"closely monitored in every respect"and that the medication will be discontinued if any concerns arise.
The study will assess the effects of puberty blockers on the physical, social, and emotional wellbeing of participants, including evaluations of bone density, brain function, and fertility.
Dr Cass also warned that without a trial, young people might continue to obtain these drugs through
"unregulated and dangerous routes."
She noted,
"Today we have young people turning up in the clinics on testosterone at 11, which we know is irreversible."
She added,
"It may be that if they were prescribed puberty blockers instead, that would give more time for the therapist to work with them and perhaps come to a different solution than a long-term life on medication."
Testosterone, a masculinising hormone, is not approved for prescription in the UK for gender treatment in children under 16.
Puberty blockers, also referred to as puberty suppressing hormones (PSH), are medications used to delay the onset of puberty.
Government and Regulatory Responses
Health Secretary James Murray addressed Parliament on Monday, emphasizing the importance of clinical evidence in guiding future decisions.
"I have felt uncomfortable and uneasy about some of the challenges raised by this matter.
But for me, following the clinical advice, basing future decisions on clinical evidence, is the right way to move forward in the context of me having received the most robust assurances about the safeguards which are in place to protect young people involved in this trial from receiving harm."
The trial was initially announced in November but was paused in February when medical regulators proposed a minimum participant age of 14.
Following extensive discussions, KCL researchers agreed on age limits of 11 for birth-registered female participants and 12 for birth-registered male participants. Recruitment is expected to begin in August, pending ongoing legal proceedings.
Legal Challenges and Campaigner Opposition
The trial faces legal challenges from campaigners who argue it is unethical and that children cannot provide fully informed consent for participation in a study that could potentially affect their future fertility.
One such group involved in legal action is the Bayswater Support Group, which supports parents cautious about medical interventions for their gender-questioning children.
A spokesperson for Bayswater Support Group expressed concerns that the trial could cause irreversible harm and would not resolve the
"outstanding questions about puberty blockers."
The Conservative Party has indicated its intention to force a vote in the House of Commons to allow politicians to express their views on the matter.
Support and Perspectives from Advocacy Groups
Chay Brown, Healthcare Director of the trans advocacy group TransActual, welcomed the trial but urged the NHS to lift the ban on puberty blockers and to
"provide timely and holistic care for all trans people on the basis of informed consent - not the latest moral panic."
Dr Cass maintains that this issue should be resolved through clinical expertise and scientific evidence, emphasizing that young people and their families have been underserved by NHS services for an extended period.
