The UK has put a pause on a clinical trial for puberty blockers aimed at children due to warnings from the Medicines and Healthcare products Regulatory Agency (MHRA) regarding the unquantified risks of long-term biological harms. The agency has recommended that a minimum age limit of 14 be implemented before any participation in the trial, highlighting the serious nature of the potential side effects linked to these treatments. Discussions are scheduled to take place between the MHRA and the trial sponsor, King’s College London, to address these wellbeing concerns.

This trial, known as the Pathways clinical trial, was initiated after the Cass review into children's gender care, which found the research supporting the benefits of puberty blockers for youth with gender dysphoria to be very weak. Hilary Cass, who led the review, indicated that the evidence base did not convincingly support the efficacy of these treatments for gender dysphoria in children and adolescents, raising further scrutiny on their use. The findings of the Cass review necessitated cautious evaluation due to the significant implications for the health and wellbeing of young individuals.

As a result of these developments, recruitment for the trial will be on hold until all issues are thoroughly resolved. There is a need for rigorous assessment and ethical consideration in conducting trials with vulnerable populations, especially when it comes to intricate matters of gender identity and medical interventions. The pause serves as a critical reminder of the importance of integrating scientific evidence with moral responsibility when dealing with treatments for young people struggling with gender dysphoria.