Puberty Blockers Clinical Trial

David Mundell Excerpts

Monday 23rd March 2026 Westminster Hall

[Several hon. Members]

rose—

[David Mundell (in the Chair)]

Order. I remind Members that they should bob if they wish to be called. As the debate is heavily subscribed, I am afraid that I will have to impose a two-minute speech limit from the start, and even that will not guarantee that everyone will be called.

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[David Mundell (in the Chair)]

Thank you, Mr Smith, for keeping to time, which I am sure Rebecca Paul will do as well.

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[Iqbal Mohamed]

Will the Minister give way?

[David Mundell (in the Chair)]

Order. I think the Minister has made it clear that she is not taking interventions.

[Karin Smyth]

Thank you, Mr Mundell.

Dr Cass also recommended that we take forward the data linkage study as part of the wider national research programme. The linkage study is not a clinical trial, and as such it will not in and of itself provide the type of evidence that can demonstrate cause and effect for any particular treatment. It is observational in nature, linking and analysing existing routinely collected data for adults who were referred as children to the Tavistock before it was decommissioned. The study requires no active patient participation; instead, it relies on an analysis of digital information held within health records and other databases.

Data linkage studies have faced difficulties that are a matter of public record, but since then there have been great efforts to improve the collaboration of the adult clinics and other organisations. Important final steps are currently being taken to enable the study to begin. We expect the study analysis to then take around one year to complete. On 26 February, we laid an order before the House to make it lawful for people and organisations to share or process data that could be subject to protections under the Gender Recognition Act 2004 where it is for the purpose of the study. That order came into force last week.

The PATHWAYS clinical trial is a key step that we are taking to build an evidence base to prove whether puberty blockers are safe and effective in treating gender incongruence and gender dysphoria. As we speak, the new clinical model is collecting a consistent and comprehensive core clinical dataset while we develop a supporting national registry.

In the meantime, hormone medications are not being prescribed. NHS England now prevents the routine use of puberty-suppressing hormones in the NHS children and young people’s gender services, and the Government have indefinitely extended restrictions that prevent them being supplied privately. Last year, NHS England issued guidance to GPs that strongly advised against supporting prescribing agreements with unregulated providers, who do not always have children’s best interests at heart. That includes online overseas providers who are known to have supplied puberty suppressants and cross-sex hormones to children in the past without any proper safeguarding. NHS England issued that warning because of the serious safety risks that unregulated providers continue to pose to children in this country. In some cases, we are talking about puberty blockers being prescribed following a questionnaire or a brief Zoom call.

I will come on to other issues around future services, although I think I have answered most questions. All clinical trials have appropriate insurance to cope with the issues outlined by the right hon. Member for Tonbridge (Tom Tugendhat). The trial sponsor is King’s College, so my understanding is that the issue raised by the hon. Member for South West Devon (Rebecca Smith) with regard to the state having conflicts does not arise. The hon. Member for Bristol Central (Carla Denyer) cited regulations that were mainly from overseas, but the UK has its own regulatory independent network: the MHRA, which we work with. The Opposition spokesperson, the hon. Member for Sleaford and North Hykeham (Dr Johnson), who I respect in her role as a paediatrician, asked a number of questions about timing and process. She will be aware that there is a judicial review, but I will make sure that she gets an answer on some of those issues.

I want to update the House that since April 2024, NHS England has opened three new services in the north-west, London and the south-west. I can confirm that a fourth service will become operational at Cambridge University hospitals NHS foundation trust very shortly. Those are important services for young people and their families who are awaiting treatment and who want to understand when and how they will receive care.