Minimum age of 11 set for UK puberty blocker trial
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- Pathways Trial researchers agreed to a minimum participation age of 11 for birth-registered females and 12 for birth-registered males, after the MHRA had previously suggested raising the threshold to 14 where no age floor had existed.
- The MHRA paused the trial in February 2026 citing safety concerns, and subsequent discussions produced strengthened safeguards including clearer stop criteria for bone density, brain function, and vaginal bleeding, plus more detailed fertility preservation information.
- King's College London researchers agreed not to recruit any participants until after 1 August to allow ongoing legal proceedings by clinicians and campaigners challenging the trial's ethics to take place, with the first recruits originally expected in August.
- Dr Hilary Cass, whose 2024 review found gender medicine operated on "shaky foundations" and triggered the 2024 ban on puberty blockers for under-18s, told the BBC it is "vital" the trial goes ahead or "we're going to have ongoing charlatans just handing out inappropriate drugs."
- Stonewall said many young people have been "left in limbo" in "emotional and physical distress" since the 2024 ban and said it was "pleased" a modified trial protocol had been agreed, though no child can participate without parental consent.
- Campaigners' legal action against the MHRA, the government and others claims the trial is unethical and that children cannot give fully informed consent to a treatment that might affect their future fertility.
Why it matters: The minimum age of 11 means the trial will enroll children at the very start of puberty, deepening the sensitivity of a study whose original design had no age floor. With legal challenges pending and a recruitment freeze until at least 1 August, the timeline for generating the evidence Hilary Cass says is needed to counter online drug sales remains uncertain — leaving gender-questioning children in continued limbo after the 2024 ban.
