MHRA Sets 11-12 Minimum Ages for UK Puberty Blocker Trial After Safety Concerns
Updated
Updated · BBC.com · Jun 19
MHRA Sets 11-12 Minimum Ages for UK Puberty Blocker Trial After Safety Concerns
3 articles · Updated · BBC.com · Jun 19
Summary
Children must now be at least 11 if birth-registered female and 12 if birth-registered male to join the UK’s Pathways Trial on puberty blockers.
MHRA pushed for tighter safeguards after pausing the study in February 2026 over safety concerns; researchers also added clearer stopping rules on bone density, brain function and vaginal bleeding, plus fuller fertility information.
King’s College London says recruitment will not begin before Aug. 1, and every participant will still need parental consent and to show they understand the treatment’s risks and possible benefits.
Legal action by clinicians and campaigners could still delay the trial, which they call unethical because minors may not be able to give fully informed consent to a treatment that could affect fertility.
The trial is central to the UK’s post-2024 ban on puberty blockers for under-18s, as regulators seek evidence on a treatment the Cass review said had been used on shaky foundations.
After years of 'shaky' evidence, can a single trial uncover the long-term risks of puberty blockers for children?
Amid legal challenges and political pressure, can this controversial trial deliver unbiased scientific answers?
Evidence Under Scrutiny: Why the UK Halted Its £10 Million NHS Puberty Blocker Trial for Trans Youth
Overview
In 2026, the UK paused the NHS 'Pathways' trial for puberty blockers after growing regulatory concerns about safety and weak evidence, despite earlier government assurances of rigorous review. This decision followed the influential Cass Review, which found that gender medicine for youth was based on shaky foundations and lacked long-term outcome data. As a result, routine access to puberty blockers for under-18s was banned, with use restricted to research trials only. These changes sparked sharp criticism from advocacy groups, who warned that limiting access could harm trans youth, highlighting the ongoing tension between patient safety, evidence, and the needs of vulnerable groups.