Cass Report Author Emphasizes Necessity of Puberty Blocker Research
Dr. Hilary Cass, the expert behind a pivotal review of gender medicine for children, has voiced her strong conviction that a clinical trial examining puberty-delaying drugs is essential for minimizing harm to young people questioning their gender. Dr. Cass stated her belief that "more children will be harmed if we don't do the trial than if we do."
Her remarks come amidst calls from certain campaigners and politicians to cancel the research program, particularly after the announcement that children as young as 11 could be recruited. The clinical trial, named Pathways, will be conducted by researchers at King's College London (KCL), who have since increased safeguards for participants and set a minimum age for involvement.
Rationale and Scope of the Trial
The recommendation for this puberty blocker research originated from Dr. Cass's 2024 review, which highlighted a lack of robust evidence supporting the use of these drugs. While the NHS previously prescribed puberty blockers for gender care in under-18s, a UK-wide ban on their prescription, both privately and through the NHS, was implemented by the government in 2024.
Dr. Cass explained to the BBC that some of the concerns regarding risks have been "exaggerated," noting that the presence of harm is genuinely unknown. She underscored the trial's "essential" role in determining the efficacy and safety of these medications. Participants will undergo close monitoring, with the drugs being discontinued if any concerns arise. The study will assess the drugs' effects on physical, social, and emotional well-being, including checks on bone density, brain function, and fertility.
"Today we have young people turning up in the clinics on testosterone at 11, which we know is irreversible. 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." - Dr. Hilary Cass
Dr. Cass believes that without such a trial, young people might resort to obtaining drugs through "unregulated and dangerous routes." She cited instances of 11-year-olds receiving testosterone, an irreversible masculinizing hormone not approved for gender treatment in the UK for those under 16. Puberty blockers, also known as puberty suppressing hormones (PSH), are intended to delay puberty.
Government and Public Response
Health Secretary James Murray addressed Parliament, emphasizing the importance of clinical evidence for future decisions. He expressed initial discomfort but affirmed his support for proceeding based on clinical advice and robust safeguards for young participants.
The trial, initially announced in November, was temporarily halted in February due to medical regulators proposing a minimum age of 14. KCL researchers, following discussions, established age limits of 11 for participants registered female at birth and 12 for those registered male. Recruitment is slated to begin in August, pending ongoing legal challenges.
Campaigners, including the Bayswater Support Group, are pursuing legal action, arguing that the trial is unethical and that children cannot provide adequately informed consent, particularly concerning potential impacts on future fertility. They contend the trial risks irreversible harm and will not resolve existing questions about puberty blockers.
Conversely, Chay Brown, Healthcare Director of TransActual, a trans campaign group, welcomed the trial. However, Brown also urged the NHS to reverse the puberty blocker ban and 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 requires resolution through clinical opinion and scientific investigation, asserting that gender-questioning young people and their families have been inadequately served by NHS services for too long.
Source: Puberty blocker trial will help reduce harm, says Cass report author