In a recent BBC interview, Dr Hilary Cass, the author of a landmark review on children’s gender medicine, strongly defended the NHS-backed Pathways clinical trial on puberty blockers. She asserted that the trial is essential for understanding the potential benefits and risks of these medications for gender-questioning youth.
The Pathways trial, conducted by researchers at Kings College London aims to closely monitor the physical, social, and emotional wellbeing of participants, including bone density, brain function, and fertility. Dr Cass emphasized that the trial is a harm-reduction measure, stating she is “absolutely convinced that more children will be harmed if we don’t do the trial than if we do.”
The Pathways Trial: Aims and Safeguards
The trial, recommended following Dr Cass’s 2026 review, which highlighted weak evidence behind the use of puberty blockers, has set minimum ages for participants: 11 for trans male participants and 12 for trans female participants. The trial was initially announced in but was paused in February when medical regulators proposed a minimum age of 14. It is set to resume in August, subject to ongoing legal action.
Dr Cass argued that without a regulated trial, young people might continue to access medication through unregulated and dangerous routes. She noted that some children are already receiving testosterone at the age of 11, which is irreversible. Puberty blockers, she suggested, might provide more time for therapeutic support and exploration of other solutions.
The trial will closely monitor participants in every respect, with the drugs being stopped if any concerns emerge. Dr Cass also addressed the exaggerated risks, stating that since UK-wide restrictions were introduced, “some of the hype about risks have been exaggerated in that we genuinely don’t know if there are harms.”
Political and Legal Challenges
The Pathways trial has faced significant political and legal pressure. Health Secretary James Murray expressed discomfort with the challenges raised but emphasized the importance of basing future decisions on clinical evidence. He received robust assurances about the safeguards in place to protect young people involved in the trial.
Campaigners bringing legal action argue that the trial is unethical, claiming that children cannot give properly informed consent to participate. TransActual’s healthcare director, Chay Brown, welcomed the trial but called for the NHS to reverse the puberty blocker ban and provide timely, holistic care based on informed consent.
The trial’s future remains uncertain as legal challenges continue. However, Dr Cass’s defense of the trial underscores the need for scientific research to guide decisions about the care of gender-questioning youth.
