UK Puberty Blockers Trial Paused as Regulator Removes Official Over Bias Claims
A major clinical trial investigating the use of puberty blockers for young people questioning their gender identity has been placed on hold in the United Kingdom. This development follows the removal of a senior health official from involvement in the trial due to accusations of bias stemming from gender-critical social media posts.
Official Recused Over Social Media Activity
Professor Jacob George, who was appointed as the chief medical and scientific officer at the Medicines and Healthcare products Regulatory Agency (MHRA) in January, has been recused from any further participation in the Pathways trial. The regulator announced this decision as a precautionary measure after social media posts made by George last year came to light.
In these posts, George described author J.K. Rowling, known for her gender-critical views, as a "treasure of our time." He also commented on the debate surrounding Olympic boxer Imane Khelif, stating that "the denial of basic biological fact is concerning" regarding questions about her gender. Although these posts predated his appointment, the MHRA acted to ensure impartiality in the trial's oversight.
Trial Details and Regulatory Concerns
The Pathways trial was designed to assess the effects of puberty blockers on children and adolescents experiencing gender dysphoria. It was scheduled to begin recruiting participants in January but was paused in February after the MHRA raised concerns about the wellbeing of the young people involved.
The trial had planned to recruit approximately 226 young people over a three-year period. Initially, the youngest participants were expected to be 10 to 11 years old for biological females and 11 to 12 for biological males, though researchers noted that rigorous selection criteria might result in older participants. However, the regulator has now recommended a minimum age limit of 14 due to concerns about "unquantified risk" and potential "long-term biological harms."
Background and Expert Reactions
This trial was announced following a recommendation from the Cass review into children's gender care, which highlighted the "poor" quality of existing research on the benefits of puberty blockers for youth with gender dysphoria. Dr. Hilary Cass, who led the review, emphasized that while the evidence base was weak, a clinical trial was necessary to provide clearer insights, given the strong beliefs held by some clinicians and families.
Critics of the trial's pause argue that there is no compelling scientific reason for the halt. Dr. Max Davie, a consultant paediatrician formerly with the NHS Children and Young People's Gender Service, stated that George's social media posts clearly indicated his personal views. Davie asserted that while individuals are entitled to their opinions, they must not allow these views to influence public duties. He suggested that the MHRA's sudden reversal lacked evidence-based justification, pointing to George's bias as a plausible explanation.
Regulator's Stance and Future Steps
An MHRA spokesperson reiterated that the safety and wellbeing of trial participants remain the top priority. The agency maintains continuous review of complex clinical trials and engages in active scientific dialogue with trial sponsors. The MHRA's multidisciplinary team of experts will continue to collaborate with King's College London to navigate the next steps constructively.
The spokesperson confirmed that George's recusal was a precautionary step following the identification of his past social media activity. The regulator emphasized its commitment to evidence-based decision-making and impartial oversight in all clinical trials.
