PARLIAMENTARY DEBATE
Puberty Suppressants Trial - 17 December 2025 (Commons/Commons Chamber)
Debate Detail
The Cass review found shocking levels of unprofessionalism, a lack of clinical oversight and puberty blockers prescribed to children without sufficient evidence that doing so was safe or beneficial to those children and young people. What Dr Hilary Cass uncovered was a scandal. That is why, on coming to office, I made the temporary ban brought in by my predecessor, the right hon. Member for Louth and Horncastle (Victoria Atkins), a permanent one. Dr Cass also recommended a thorough study to establish how best to support children and young people who suffer gender incongruence. That is the pathways study.
The study has four main parts, one of which is the clinical trial to study the effects of puberty-suppressing hormones on young people’s physical, social and emotional wellbeing. The other aspects of the pathways study will track the physical, social and emotional wellbeing of all young people attending UK NHS gender services. It will look at young people’s thinking and brain development, following both those who are and are not taking puberty-suppressing hormones, and it will gather evidence directly from young people, parents and staff about their experiences of living with gender incongruence.
The bar for the trial to be approved was extremely high and oversight will be rigorous. Children cannot consent to being on the trial, so places will require parental consent, as well as the assent of young people. It is because protecting and promoting the health and wellbeing of affected young people is our primary concern that there are also strict eligibility criteria in place to join the pathways clinical trial. As such, the number of young people who would expect to qualify for the trial will also be low. Participants must undergo thorough mental and physical assessments and will be followed over a number of years with regular wellbeing checks. Puberty blockers have also been used to delay puberty in children and young people who start puberty much too early. Use in those cases has been extensively tested and has met strict safety requirements for that use.
The study is led by King’s College London and the South London and Maudsley NHS foundation trust. It has been carefully checked by independent scientists who advise the National Institute for Health and Care Research and by the Medicines and Healthcare products Regulatory Agency, and received approval from a research ethics committee. I am treading cautiously in this area because the safety of children must come first.
The first and most obvious question is: why? Why have this Government chosen to fund experiments with puberty blockers on physically healthy children? Despite saying he was comfortable with this trial in a briefing to MPs, the Secretary of State told the media on Friday and the Select Committee this morning that he is in fact uncomfortable with it. Why is it even being considered before the data linkage study is complete?
Some 9,000 children went through the Tavistock clinic, and many of them came out regretting being encouraged to irreversibly damage their bodies. We should look carefully at those outcomes before we make the same mistakes. What steps is the Secretary of State taking to secure the data from the Tavistock and have it analysed? What steps is he taking to hold to account those obstructing access to data linkage information? What assessment has he made of the motivations of those obstructing that data, when this is a study to safeguard children?
And what of the trial itself? We know that 226 children will go through this trial. Is that a limit or a target? Those children will be randomised to get puberty blockers now or in a year’s time, and all will be analysed at two years. They will still be children. They might be only 11 years old. How can the results demonstrate a meaningful outcome? The control group is not properly randomised, but chosen from the Horizon intensive trial group. Is the Secretary of State concerned that this will introduce bias?
The criteria for getting puberty blockers in this trial require just one parent to consent and the clinician to think that it will benefit the child, but on what basis will the clinician decide? The Cass review said that the vast majority of children with gender dysphoria would recover, with only a few persisting with trans identities into adulthood. It is not possible to predict which those children will be, so does the Secretary of State accept that the vast majority of children in this, his Streeting trial, who will be given drugs will be physically healthy children whose distress would get better without any puberty blockers, and that the vast majority of the children in this trial are therefore being unnecessarily experimented on with risky medications under his leadership?
I will tell the hon. Lady why. It is because, under the previous Government, those puberty-suppressing hormones were prescribed without proper oversight, supervision or safety, yet we did not hear a peep about that fact for years until Dr Cass, commissioned by Sir Sajid Javid—who deserves enormous credit—did the study, which was published and widely supported and which contained this recommendation. The Conservatives may have changed their tune in opposition, but I remember what they said in government when they published the Cass review and supported its recommendations, so I think their response now is a real shame.
The shadow Minister accuses me of inconsistency, so let me be clear. Am I comfortable that this clinical trial has undergone the proper process and ethical approval to ensure the highest standards and supervision? Yes, I am comfortable about that. Am I uncomfortable about puberty-suppressing hormones for this group of young people for this particular condition? Yes, I am—because of risks. It is why I was also uncomfortable when I upheld the temporary ban by my predecessor and then put in place a permanent ban. The reason I was uncomfortable with that, too, is because I had to look children and young people, and their parents, in the eye when they told me in no uncertain terms that that decision was harmful to them, as have many other clinicians who have opposed that decision.
Whatever my discomfort in this extremely sensitive area, the reason that I have made this decision is that I am following clinical advice and, as Health Secretary, it is my responsibility to follow expert advice. Had the Tavistock clinic faced such challenge and scrutiny a decade ago, we would not be in this mess. The Conservatives were right to commission the Cass review and they were right to accept its recommendations. I accept that there is now a difference on this particular recommendation, but I would urge Members not to walk away from the cross-party consensus we built behind that approach but to build on the work that Dr Cass has done.
Let me turn to the important questions raised by shadow Minister. There will be two groups within the trial, as well as a further control group of children and young people with gender incongruence who do not receive puberty-suppressing hormones. At least 226 participants are required in order to detect a statistically significant difference between the two treatment groups. However, this is not a target and no young person will find themselves on this trial because there is a drive to make sure that a certain number of young people are participating. In order for anyone to participate in this trial, it has to have the most robust clinical oversight from clinicians within the service, as well as national oversight and the consent of parents. It is only where young people will be deemed to benefit that they will be on this programme.
The shadow Minister asks about the data linkage study. That is important. The data linkage study will be undertaken, but when it is completed it will not provide us with the same evidence as this clinical trial. That is why Dr Cass made a distinction between this trial and the data linkage study.
The hon. Lady also asks about the motivations of those who withheld data. That is an extremely important question. It is utterly appalling that anyone in a position of responsibility in the NHS withheld data on a very vulnerable group of children and young people. I accept that there were many well-meaning people involved in these services at the Tavistock clinic, but the fact that Dr Cass found such a lack of rigour, such a lack of standards and such a lack of proper oversight is disgraceful. It is the clinicians who are well meaning and ideologically driven who have given me the most cause for concern in this whole debacle and who have done more harm to children, young people and the trans community than most other people who have taken part in this debate.
I appreciate the work that Dr Cass has done, and I am glad that she is in the other place, bringing welcome scrutiny. Were she not supportive of this approach, I might think again, but she has made her recommendation and given her support. I am following clinical advice. It is not comfortable, but I do believe it is the right thing to do, on balance.
Given that the numbers on the trial will be very small and the waiting list for talking therapies, which are so important for children and their parents, is very long, with hundreds of thousands waiting, can the Secretary of State explain how he will increase access to NHS talking therapies so people can get the help they need and deserve? In a field with so little research, will he confirm if the pathways trial will look at international best practice in order to take learnings from abroad?
NHS England has opened three new children and young people’s gender services in the north-west, London and Bristol, with a fourth planned for the east of England in 2026. We aim to have a service in every region of England in the coming years. These services use a different model with multidisciplinary teams, including mental health support and paediatrics, within specialist children’s hospitals to provide good clinical care. The new services will increase capacity and reduce waiting times so that patients can be seen sooner and closer to home. We have also commissioned additional support for young people waiting to be seen through local children and young people’s mental health services.
We have to have this debate with due care and sensitivity for young people in this vulnerable group in particular and for the wider trans community, who feel extremely vulnerable in this country at the moment, including as a result of decisions I have taken as the Health and Social Care Secretary. We have to consider all of that in the round, but we must make sure that at all times we are following the evidence, that we are open to scrutiny and challenge, and that where we are making these finely balanced judgments, we are doing so with rigorous debate, testing the arguments, the evidence and the data. That is why I welcome the urgent question and this discussion.
I’ll tell you what: I will take an evidence-based approach. I have done that on this issue from day one. Had the Conservatives done so, we would never have seen the Tavistock scandal. We would never have seen puberty blockers dished out willy-nilly to children and young people in this vulnerable patient group. I have sought at all times, including when I sat on the Opposition Benches, to treat this debate with the care, sensitivity and humility it deserves, and not to be tribal in my interactions. I only wish this Conservative Opposition would take the same approach.
King’s College operates the highest standards of safety. Does the Secretary of State agree that its expertise and rigour will support the wellbeing of participants and ensure that we get the robust evidence we need and that vulnerable children are no longer treated as political punchbags?
The Cass review found that puberty blockers have been prescribed routinely without good evidence for their safety or effectiveness, and that is why a clinical trial was proposed. They are licensed and used safely in much younger children for precocious puberty or in older adults for certain cancers. For adolescents, the interaction with all the different processes of puberty may be very significant, which is why more evidence and a better understanding of their impact is needed in this patient group. Anyone on the trial can choose to stop taking puberty-suppressing hormones and leave the trial at any time; they do not need to give a reason. If a young person decides to stop taking puberty-suppressing hormones, their care in the NHS, including the gender service, will not change in any other way, and their doctors will explain to them and their parents or guardians what treatment options are available.
I know that there are concerns about the longer-term impacts on fertility. Prospective participants will be given comprehensive information on the advantages and potential risks of the hormones, including details about preserving fertility. Doctors will explain the possible long-term consequences and available options. Young people will also be offered consultation with a fertility specialist. The young person and their parent or guardian must clearly demonstrate a full understanding of all these issues—only then, after that, would a clinician sign off on admission to the trial.
I recognised when I took the decision, and as a result of representations I have received, both directly and in writing, that it caused considerable pain and distress to a very vulnerable group of children and young people and to the people who care very much about them. I have not been indifferent to that; I have taken it very much into consideration. However, with respect to all the people I have met, no amount of political pressure should move a Health Secretary away from the clinical advice and expert opinion that should underpin these sorts of decisions.
May I ask the Secretary of State—a man who I know to have empathy and thoughtfulness—to speak directly to trans people who will be watching this debate? At this Christmas time, they may be struggling with estrangement from family and with other difficulties. Can he speak to the dignity and worth to which they are entitled, and send a message that this House has their back?
When it comes to the care and health of children and young people in particular, I make no apology for exercising extreme caution. I do want trans people in our country to know that this Government respect them and their identity, and want them to live with dignity, safety and inclusion. That is the approach that the Government are taking. I realise that decisions that I have personally taken have not been received in that way. That has not been comfortable for me, but I do believe it has been the right thing to do.
Whatever the Cass review says, in the end this is the Secretary of State’s judgment. I remember the covid inquiry repeatedly saying that it was wrong for Ministers to hide behind “the science”. Equally, there is no single clinical advice on this question: clinicians are as divided as the rest of society. We rely on the Secretary of State’s judgment. I am afraid that I think he has got it wrong.
On the question of sex, the right hon. Gentleman is right: sex is immutable. Even if there has been treatment with hormones or surgery, underlying biology none the less means that trans women, for example, would still need to be screened and treated bearing in mind their biological sex, and the opposite is true for trans men. We have to draw that distinction between biological sex and gender identity.
Whatever my discomfort and personal views about this particular trial or about the notion of young people using puberty blockers in this way, I cannot ignore, and should convey faithfully to the House, conversations that I have had with trans young people and adults. They have described in powerful and unforgettable terms not just the life changing, but the life enhancing experience that they have had. I am thinking particularly of the university student I met; if she walked into this Chamber now, we would assume that she was born female. She is living her best life and described in very powerful and unforgettable terms the impact that treatment has had for her and her quality of life. At the same time, I think of high-profile cases such as Keira Bell’s. That is why we have to tread extremely carefully in this area, to follow evidence and to build an evidence base. It is also why these are such finely balanced judgements and why I can be simultaneously uncomfortable with the permanent ban that I put in place and uncomfortable with the clinical trial. I hope that I have reassured people that I think very deeply about these issues before taking decisions.
We will ensure that young people get good access to wider evidence-led support. I have had to wrestle with the fact that some trans people enter adulthood without ever receiving any sort of healthcare, and I have been heavily criticised by those people in particular for some of the decisions that I have taken. We are working to reduce waiting times, as I have described.
My hon. Friend says that puberty blockers are reversible. We hear contrary views about that from Members across the House, some of whom say that puberty blockers are irreversible. The truth is that the evidence in this area is mixed, which is why we need to build a stronger evidence base.
I appreciate the right hon. Member’s sympathy. I have wrestled with this issue probably more than any other ethical decision that I have had to make in this office. I do not seek any pity or sympathy for doing so—it is the job that I signed up to and a job that I love doing. I have taken great care and sensitivity in this area because of the particular vulnerability of this group of children and young people.
The hon. Member talks about placebo. For obvious reasons in this case, a placebo would not be appropriate, because it would be very obvious whether a young person was receiving the real medication or the placebo, but the trial design has included a control group. The way in which the trial is established will help us to distinguish between the benefits of receiving or not receiving this particular medication, and there will be really close oversight of the impact on development, but he is right that we need to judge these things on the question of risk. That is what led Dr Cass to make her recommendation, and that is why I support it.
I understand the sensitivity surrounding this issue, and the hon. Lady is right to say that people in our country have received life-changing clinical interventions that they later regretted. As part of that regret, they have shared that they did not feel, at the time, that they were making or could have made an informed decision. That is why this trial is set up in such a way that it has such strong clinical oversight locally as well as nationally. It cannot happen without not just the assent of a young person but the consent of their parent or guardian. Those are important protections and safeguards. I do not share the hon. Lady’s characterisation of the trial.
“Why is money being spent on this pathway when my child has been waiting for clinical support for 3 years and the waiting list is so long she may be moved to adult treatment? Why is Government prioritising the tiny few over the many? With our children’s mental health services at breaking point and parents at their wits end trying to get their child diagnosed”,
how do the Government look in the eyes of the parents with rare diseases whose drugs are not funded by the NHS when they are funding this trial?
The Health Secretary says that he is “uncomfortable” with this experiment, and his instincts are correct. In the haunting words of Keira Bell, a courageous young woman and a victim of the Tavistock scandal:
“I was an unhappy girl who needed help. Instead, I was treated like an experiment.”
When these children who are now going to be experimented on become adults, they will want to know who did this to them. This time, the truth will be that this was state-sanctioned, out in the open and—I am afraid to say—at the Health Secretary’s say-so. I am begging the Health Secretary to use his power as the politician in charge to do what he must know is right and stop this.
During my election campaign, I met a fantastic mother—no mother could have loved their daughter more. She told me about how, when her daughter entered puberty, she had to come to terms with her biological sex, and about the impact on her mental health. To delay puberty, she stopped eating. She ended up arriving at hospital in an ambulance, so weak that she had to be treated in that ambulance. I welcome the fact that the trial will look at some of the side effects of puberty blockers, but will it also consider the impact of not taking puberty blockers in some cases? Will the Secretary of State also tell us how the House will be kept up to date on the trial as it progresses?
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