A controversial NHS-backed trial giving puberty blockers to children as young as eight has been dramatically halted after Britain’s medicines watchdog intervened over safety fears.
The Medicines and Healthcare products Regulatory Agency (MHRA) has pressed pause on the Pathways study, warning of potentially “significant” and unquantified long-term harms. Officials are now demanding urgent talks with trial leaders at King’s College London, including whether the minimum age for participants should be raised to 14.
The study, funded by the NHS and due to begin in April, was set to involve 226 children who believe they are transgender. It has already sparked outrage after it emerged that participants could receive up to £500 in Love2Shop vouchers for completing psychometric tests.
In a stark letter, the regulator warned that puberty blockers—particularly if followed by cross-sex hormones—are “very likely” to leave children infertile. It also raised concerns about the risk of persistent bone structural changes if the drugs are used for more than a year, possible impacts on brain development, and whether very young children could cope with side effects such as vaginal bleeding.
The Department of Health and Social Care confirmed that “preparations for the trial have been paused” while regulators and clinical leaders examine the new concerns. Health Secretary Wes Streeting has previously admitted he “wrestles” with the decision and is “not comfortable” with the trial going ahead. He also acknowledged in Parliament that children cannot legally consent, instead providing “informed assent” alongside parental approval.
Puberty blockers were permanently banned for routine use in 2024 following the Cass Review, which found the evidence supporting their use in gender-distressed children to be “remarkably weak” but called for controlled research.
Critics say the trial should now be scrapped entirely. Reform UK leader Nigel Farage branded it “state-sponsored child abuse,” while campaigners have staged protests demanding ministers pull the plug for good.
