A new UK clinical trial, called Pathway, is beginning to investigate the risks and benefits of puberty-blocking drugs for young people experiencing gender incongruence (the experience of feeling a mismatch between your gender identity and the sex you were assigned at birth) or gender dysphoria (the distress, unease or discomfort caused by this mismatch). These drugs pause the physical changes of puberty and have previously been used in gender services but were restricted to research-only use in the UK in 2024 following the Cass Review, which highlighted a lack of robust evidence on safety and effectiveness in under-18s.

Because of this ban, puberty blockers can now only be offered within a research study. The Pathway trial, run by researchers at King’s College London, will recruit around 220 participants under 16, all of whom have already entered puberty and have a diagnosis of gender incongruence. Participants must meet strict medical and psychological criteria, undergo screening, and demonstrate an adequate understanding of the treatment to give informed consent. Parental consent is also required.

Participants are randomly allocated to one of two groups: one group will receive puberty blockers immediately, while a second group will begin treatment 12 months later. Researchers will monitor physical outcomes (e.g., bone density, brain development) alongside psychological well-being and quality of life. Initial findings are expected in about four years.

The study has received ethical approval but remains controversial. Critics argue that it is unethical to expose children to drugs previously deemed unsafe, while others emphasise the need for high-quality evidence. Legal challenges have been threatened by campaigners such as Keira Bell, whose earlier court case raised questions about whether under-16s can truly give informed consent. Supporters, including Dr Hilary Cass, argue that only a controlled trial can resolve uncertainties and provide clearer guidance for families and clinicians.

While the main clinical trial focuses specifically on puberty blockers, a larger observational study looks at a wide range of young people (N=3000) receiving various types of care (psychological support, social support, or no medical intervention). Because it is observational, nothing is manipulated; researchers simply track outcomes over time.

A representative from the LGBTQ+ rights charity Stonewall emphasised that young people deserve access to high-quality, evidence-based medical care. They called on the government and policymakers to prioritise investment in healthcare for trans young people and to ensure that the perspectives of these young people and their families are central to any decisions made.

References:

New puberty blockers trial to begin after UK ban https://www.bbc.co.uk/news/art...;(accessed 24.11.25)

Read more about the trial here: https://www.kcl.ac.uk/research...;(accessed 24.11.25)

Gender dysphoria https://www.nhs.uk/conditions/...;(accessed 24.11.25)

Support for trans, non-binary and gender diverse children, young people and their families https://mermaidsuk.org.uk/

ANSWER THE FOLLOWING QUESTIONS!

1. What is the independent variable in the clinical trial?
2. What are the dependent variables?
3. Around 6 children per month will join the trial. How could the researchers ensure they are randomly allocated to the two conditions?
4. Briefly outline at least one ethical issue which has been addressed as part of this trial and how the researchers have addressed this.
5. What could be the implications of this piece of research be for the UK economy?