Puberty Blockers

Debate between Scott Arthur and Tom Hayes

Tuesday 23rd June 2026 Commons Chamber

[Dr Scott Arthur (Edinburgh South West) (Lab)]

This has been an interesting debate so far and I am grateful to follow the hon. Member for Canterbury (Rosie Duffield), who has worked so much in this area. We should all acknowledge that this is not an easy issue.

The reason why I wanted to speak in the debate is that back when I was trying to get elected in 2024, I met the mother of a young trans woman. She told me about how her daughter really started to come to terms with who she was when she was entering puberty, but that led her to stop eating because she did not want to go into puberty. Her condition got so bad that she had to be taken to hospital, and she almost died. We should not view this as a lifestyle choice, and we should not think that doing nothing comes with no consequences. I know that not all cases are the same, but the reality is that doing nothing is not the answer. We do have to answer these questions.

I welcome the news this week that the Pathways trial is set to go ahead. Since the Government announced an indefinite pause on the prescription of puberty blockers last year, both young people and clinicians have been stuck in limbo. This uncertainty has helped no one—not the young people who are desperate for medical support, nor the researchers who need to gather data to fully understand the effects of these drugs. However, it is right that this renewed permission for a trial is based on clinical judgment, not political discourse. We should be led by science, not politics, where the health of our young people is concerned.

King’s College London and the MHRA have worked extensively to propose a safe and ethical trial, increasing safeguards since March and continuing dialogue with the Health Research Authority. I understand the concerns around the trial, and I think we all should. We all want to ensure the safety of the children involved, but it is time we find a way forward that balances the safety of the young people involved and the opportunity to enhance the care that we provide for children struggling with their gender identity. Far too often, that care is lacking.

Many Conservative Members have consistently called for the full implementation of the Cass review. Baroness Cass was quoted multiple times by the shadow Minister in her introduction to this debate, yet the Conservatives have called this debate to oppose the trial, despite it being one of Baroness Cass’s recommendations. Why are the Conservatives not willing to listen to Baroness Cass on that single issue?

In her original review in 2024, Baroness Cass made it clear that research into puberty blockers was necessary. Just this week, she has said that the trial to examine the risks and benefits of puberty blockers will reduce harm, not cause it. In fact, she goes further and tells us that the debate around the risks of puberty blockers has been exaggerated—we have seen some of that today, if we are all honest. She is absolutely right on this point.

[Tom Hayes (Bournemouth East) (Lab)]

The Conservative Government commissioned the Cass review. In their 2024 manifesto, the Conservatives committed to implement the review in full, which would include a trial. However, as my hon. Friend is saying, they now propose in this motion to stop the trial. Is that not proof that we actually need to have a trial? We need to take the party politics out of this matter, stop politicians from being the lead commentators and put it in the hands of the families and the clinicians.

[Dr Arthur]

Exactly. Baroness Cass is a respected expert in this field, and she made recommendations that were broadly accepted. We should be using science as a basis for decision making, not rejecting her findings purely on the basis of politics. Let me go back to what I said at the start: doing nothing will lead to our young people being harmed. That is an incredibly important point.

We cannot rely on debates in this place to decide how and when puberty blockers should be used. Rather, we should be relying on thorough scientific research, carried out in proper trial conditions and led by medical experts. We heard earlier the Health Secretary explaining some of the detail around protections for our young people. Baroness Cass is also clear that more children will be harmed by preventing the trial than by allowing one to go ahead. That is an incredibly important point.

Preventing a trial drives desperate children to look online or internationally for unregulated hormones or hormone suppressants. That leads young people to unsafe puberty blockers or to start taking hormones such as testosterone at a much earlier stage, which are irreversible once they start to take hold. We can prevent that by providing the properly regulated use of puberty blockers in the UK via this trial. The trial will provide understanding and allow clinicians to effectively guide Government on our next step. It is the right and necessary thing to do for the Government, clinicians and young people. We need to take better care of our young people, and we need to do that via a clinical trial.

Let me say again that doing nothing might seem like the easy thing to do, but it will come with consequences. I really hope that we hear more from Opposition Members about what they think the consequences of doing nothing will be for the health and wellbeing of our young people, because we have not heard that.