Puberty Suppressants Trial

Caroline Johnson Excerpts

Wednesday 17th December 2025 Commons Chamber

[Dr Caroline Johnson (Sleaford and North Hykeham) (Con)]

(Urgent Question): To ask the Secretary of State for Health and Social Care if he will make a statement on the pathways puberty blockers trial.

[The Secretary of State for Health and Social Care (Wes Streeting)]

Let me just start by acknowledging the sensitivities around this issue and the strong beliefs held around this House. For all the division and divided opinion, I believe that there is a determination shared by everyone in this House to do the right thing by a vulnerable group of children and young people. It is for those reasons that I am taking the course of action that I am. Put simply, that is to follow expert clinical advice and take an evidence-led approach.

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.

--- Later in debate ---

[Dr Johnson]

I must first declare my interest as a consultant paediatrician who has looked after children with gender dysphoria in the past and is likely to do so in the future. We must remember that we are talking about vulnerable children.

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?

[Wes Streeting]

The shadow Minister asks, “Why?” There is a simple answer. It is because this was recommended by Dr Cass in the Cass review, which was commissioned by my predecessor, Sir Sajid Javid. I think that was the right thing to do, and it is why, when my predecessor brought forward the Cass review, I supported it in opposition. I certainly did not try to play politics with an extremely vulnerable group of children and young people.

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.