NHS Urged to Halt Puberty Blocker Trial Following Supreme Court Judgment

Trial of banned drugs is due to begin despite the ruling, which campaigners say means the premise for treating gender dysphoria in children has ‘fallen away.’

Susan Smith (L) and Marion Calder, co-directors of For Women Scotland, outside the Supreme Court in London on April 16, 2025. Lucy North/PA

A group of campaigners is urging the NHS and the government to halt a planned puberty blockers trial in light of the recent Supreme Court judgment on the legal definition of sex.

The four campaign groups wrote to NHS CEO Sir James McKey and Health Secretary Wes Streeting on April 28 asking them to urgently reconsider the trial because the ruling means that young people who wish to “transition” through drugs and surgery cannot be guaranteed legal status as the opposite sex.

The proposed trial has been accused of using vulnerable children as “guinea pigs“ for the hormone-suppressing drugs, which are indefinitely banned from being prescribed to under-18s in the UK, either on the NHS or privately.

Authored by Sex Matters, the LGB Alliance, Transgender Trend, and Genspect, the letter asks McKay and Streeting to immediately cancel the trial, as it has been “made untenable by the recent judgment of the Supreme Court in the case of For Women Scotland v Scottish Ministers.”

Last month’s landmark judgment confirms that the correct interpretation of the protected characteristic of sex for the purposes of the Equality Act 2010 is “biological sex only,” regardless of whether a person has obtained a Gender Recognition Certificate which says they have legally changed gender.

Interim guidance issued by the Equality and Human Rights Commission published following the Supreme Court’s unanimous ruling means that single-sex spaces, services, and associations must not be open to people of the other sex, or businesses and public bodies risk legal action for failing to uphold women’s legal rights.

The letter says that young people seeking to be part of the trial, or to have other interventions in future, need to have the far-reaching implications of the judgment made clear to them.

“Children under the care of all gender services, both NHS and private, must now be told that they will never be able to access spaces or services for the opposite sex, no matter what legal or medical steps they take now or in the future.

“Such children will, throughout their lives, need to use either the spaces and services designated for their own sex or an alternative provided for both sexes (mixed-sex or single-user) if available.”

The campaigners continue, “This means that the entire premise of treatment with puberty blockers for gender dysphoria has fallen away.”

‘Restricted Employment Opportunities’

The drugs, known as gonadotropin releasing hormone analogues, or GnRHa, are intended to block children’s natural puberty so that if feelings of gender dysphoria persist and they later progress to cross-sex hormones and surgery, they will “pass” better as the opposite sex.

The letter says that “passing” as the opposite sex may cease “to be a desirable goal to present to children when they will never be permitted to use spaces or services for the opposite sex, and may in future be restricted in employment in roles such as police officer or nurse which can involve intimate contact with others in situations where sex matters for those others’ human rights.”

The campaign groups involved have consistently argued that it was both unethical and a breach of human rights principles to treat young people’s mental distress with what they term “major, unproven physical interventions with known harms.”

Undated photo of Maya Forstater, co-founder of campaign group Sex Matters. Nicole Jones/Handout via PA

As well as interfering with normal adult sexual function and fertility, puberty-blocking drugs—which are essentially the same as the cross-sex hormones given to adult transgender patients—can stunt growth and result in reduced bone density, and cause a raft of other health problems.

The testosterone-suppressing drugs given to men who wish to present as women are also used for the castration of sex offenders and in the treatment of prostate and other cancers. Studies have shown they affect the functioning of the brain in ways that are not yet fully understood.

Potential Serious Side-Effects

Known side-effects of the testosterone blocking drugs include an increased risk of blood clots, cardiovascular disease, and slow-growing tumours affecting the brain and spine, as well as gallstones, dehydration, and increased urination. Over time, these drugs may also increase the risk of type 2 diabetes, high blood pressure, and osteoporosis in men.

With the oestrogen-suppressants given to women desiring a more masculinised appearance—usually prescribed in conjunction with testosterone—known and common side-effects include high blood pressure, weight gain, acne, male pattern baldness, increased risk of cardiovascular disease, osteoporosis, and type 2 diabetes. They also decrease levels of cholesterol in the brain, believed to be linked to the development of Alzheimer’s disease.

The campaigners add in their letter that since no promise can be made that medical treatment will enable a person to fit in or go unnoticed while using opposite sex facilities, “the use of these drugs on children too young to understand this is ethically untenable.”

Bayswater is a support group for the parents of trans-identified adolescents and young people who advocate for evidence-based care, and have all resisted what a spokeswoman for the group called “unrelenting pressure” to allow their children to take puberty blockers.

The group told The Epoch Times: “The decision not to reveal the research protocol pending ethics approval creates additional anxieties, since families will not know whether their children could be recommended for an irreversible pathway. This uncertainty is stopping many parents from accessing CAMHS [Child and Adolescent Mental Health Services, where referrals to gender clinics are made].

“Parents already report that children are using extreme pressure and emotionally coercive demands to get them to agree to medicalisation. Understandably, parents fear being put in a position in which they feel forced to provide consent.”

Permanently Banned

Puberty blockers were permanently banned throughout the UK after Streeting extended a temporary ban imposed by the previous Conservative government. The High Court ruled that the initial ban was lawful after it was challenged by the campaign group TransActual and a trans-identifying teenager.

In spite of the ban, children and teenagers suffering gender confusion will still be able to access the drugs on the trial, which will be carried out by a team of researchers led by King’s College London as part of a contract worth £10,694,902.24.

In her independent review into children’s gender services, leading paediatrician Baroness Dr. Hilary Cass said there was “remarkably weak” evidence to support the use of the drugs, which “may permanently disrupt the brain maturation of adolescents, potentially rewiring neural circuits that cannot be reversed.”

Following Cass’s report, plans for the trial were announced as part of a multi-million-pound NHS-funded package of research into child gender dysphoria.

Illustration by The Epoch Times, The Cass Review, Getty Images, Freepik

‘We Don’t Know Enough’

The trial has been approved by the National Institute for Health and Care Research (NIHR) and is part of a wider study, known as PATHWAYS, set to conclude in 2031.

The NIHR says that the rationale for prescribing blockers is that they “might give young people time to think about their identity without worrying about their bodies changing during puberty. However, we don’t know if GnRHa are safe and helpful for young people with gender incongruence.”

“We also do not know enough about how identity and feelings develop for young people with gender incongruence as they grow up and what treatment is helpful. The PATHWAYS research study will provide new and important evidence that will help young people with gender incongruence, along with their parents and health professionals, to make informed choices about the care and support options that are most likely to be helpful.”

It will see young people, with the agreement of their parents or carers and NHS gender services, given puberty suppressing hormones over a two-year period.

Researchers will aim to monitor the physical, social, and emotional well-being of the youngsters recruited onto the trial, carrying out cognitive testing and brain scans to ascertain whether using puberty blockers affects a subject’s learning ability and brain development.

The scandal-hit Tavistock clinic for children suffering gender incongruence, which has now been closed down, carried out an Early Intervention Study of puberty blockers given to 12- to 16-year-olds, from 2011 to 2014, although it did not report the findings until 2021.

The clinical research showed no improvement in children’s reported gender distress or mental health following use of the medication. The report also revealed that the vast majority of youngsters put on puberty blockers progressed to treatment with cross-sex hormones as young adults.

The Cass Review found that the majority of young people grow out of their feelings of gender incongruence, which persists only for a “small minority” of people. Her review found that youngsters with mental health problems or those on the autism spectrum were frequently misdiagnosed with dysphoria.

Keira Bell outside the Royal Courts of Justice in central London, where a landmark case to stop the NHS prescribing "experimental" puberty blockers and cross-sex hormones to children who wish to undergo gender reassignment reached the High Court, in London on Jan. 22, 2020. Sam Tobin/PA

Threat of Future Litigation

Keira Bell, a woman who was given puberty blockers when she was 14 before going on to have a double-mastectomy in a bid to present as a man, came to regret her decision and took legal action against the Tavistock and Portman NHS Foundation Trust’s Gender Identity Development Service, in a bid to halt the prescribing of puberty blockers.

Bell, together with the parents of a teenager seeking to prevent their child being given the drugs, initially won the case in 2020, but the decision was overturned on appeal, allowing the prescribing of puberty blockers to continue until the government intervened in the wake of the Cass Review.

Earlier this year, a solicitor reportedly instructed by Bell and psychotherapist James Esses, wrote to the Health Research Authority (HRA), the body responsible for protecting the interests of patients and the public in health and social care research, to warn them of potential future litigation if children are harmed in the trial, or come to regret taking the drugs in the future.

The HRA told The Epoch Times in a statement that it has yet to receive the application for the study.

“We are expecting an application from the PATHWAYS programme of research for a clinical trial, but we have not received [it] yet. If an application is received it will be reviewed in line with our standard operating procedures for Research Ethics Committees (RECs), as would any other clinical trial. A REC reviews the ethical considerations of a study and gives an opinion on whether it should proceed. A summary of any study given a final opinion by a REC is published on our website no earlier than 90 days of the final opinion being given.”

The Epoch Times has contacted NHS England and the Department for Health and Social Care for comment.