Endorsement of the CitizenGO Petition: Stand with Keira and James – Help Stop Harmful Puberty Blocker Clinical Trials
I feel compelled to speak on behalf of the most vulnerable among us—our children. In light of the UK government’s recent decision to ban puberty blockers for individuals under 18 due to “unacceptable safety risks,” it is deeply troubling that the NHS intends to proceed with a £10.7 million clinical trial on these very same drugs¹.
This trial, set to run until 2031 under the oversight of King’s College London, comes despite clear medical and ethical concerns raised by leading experts, including those involved in the Cass Review². These drugs, once heralded as a harmless pause on development, are now acknowledged to carry significant, irreversible risks—especially to cognitive and physical maturation³.
The Scientific and Medical Concerns
The use of puberty blockers in children with gender dysphoria is not supported by robust, long-term scientific evidence. The Cass Review, an independent inquiry led by Dr. Hilary Cass, found that the available studies on puberty blockers were of “very low certainty” and that the risks outweighed the unproven benefits⁴. Among the most pressing concerns are:
- Cognitive Development: Puberty is a critical period for brain maturation. Research suggests that halting this process may have detrimental effects on memory, executive function, and emotional regulation. A 2020 study found that children on puberty blockers showed decreased IQ scores, possibly due to the impact on brain plasticity⁵.
- Bone Density Loss: Puberty is essential for bone mineralization. Studies have shown that children placed on puberty blockers experience significantly lower bone density than their peers, increasing the risk of osteoporosis and fractures later in life⁶.
- Fertility and Sexual Function: The long-term consequences of halting natural puberty on fertility and sexual function are not well understood. However, evidence suggests that children who progress to cross-sex hormones after puberty blockers may face irreversible sterility⁷.
- Psychological Outcomes: Proponents of puberty blockers argue that they reduce distress in gender-dysphoric youth, yet the evidence is inconclusive. In fact, studies have shown that many young people’s gender dysphoria resolves naturally if puberty is allowed to proceed. Blocking this process may reinforce distress rather than alleviate it⁸.
The UK government’s decision to ban these drugs was based on the assessment of the Commission on Human Medicines, which found that the safety profile of puberty blockers does not justify their continued use⁹. The notion that an NHS clinical trial will provide clarity is misleading—existing evidence already raises significant alarm, and ethical considerations make further experimentation on children unacceptable.
A Pastoral and Moral Duty
Keira Bell’s courageous testimony, alongside that of James Esses, has already demonstrated the tragic consequences of prematurely medicalizing gender dysphoria. Their voices, and those of countless others who have suffered under ideologically driven policies, must not go unheard. It is unconscionable to proceed with clinical trials that will place more young lives at risk in pursuit of an agenda that prioritizes political expediency over scientific caution¹⁰.
For several years, I have raised my voice against the dangers of medicalizing gender dysphoria, particularly among children. In 2021, alongside over 2,500 Christian ministers and pastoral workers, I signed an open letter to the Secretary of State warning against irreversible interventions such as puberty blockers, cross-sex hormones, and surgeries¹¹. That letter reaffirmed our Christian duty to guide young people toward accepting their natural, God-given bodies rather than leading them down a path of lifelong medical dependency and regret. This commitment to truth and pastoral care has remained a cornerstone of my ministry.
Advocacy for Supporting Families
In addition to these efforts, I have been actively involved in supporting families navigating the challenges posed by ideologically driven educational materials. As a co-founder of PSHEbrighton, I have worked to provide a platform for families to voice their concerns, seek advice, and collaborate in advocating for comprehensive and factually accurate Personal, Social, Health, and Economic (PSHE) education¹².
In 2024, legal experts, including Karon Monaghan KC, reviewed Brighton and Hove City Council’s Trans Inclusion Schools Toolkit and raised concerns about its legal robustness. The review indicated that the toolkit might be in breach of equality laws and could potentially violate the rights of young people, thereby exposing public authorities to legal challenges¹³.
Despite these well-founded criticisms, the council proceeded without adequately addressing the issues raised. Such actions exemplify the dangers of allowing ideology to override the best interests of children and the rule of law.
A Call to Action
Therefore, I strongly endorse CitizenGO’s petition to halt these harmful trials and urge all people of goodwill—especially those entrusted with the safeguarding of children—to lend their support. By signing this petition, we send a clear message: children deserve protection, not experimentation. Let us stand together for the safety, dignity, and well-being of the young, resisting dangerous medical interventions that history may well judge as a grave moral failing.
May God grant us the wisdom and courage to uphold the truth.
✠Jerome Seleisi
Titular Archbishop of Selsey
- The Times, “Puberty blockers banned because of ‘unacceptable safety risks'” (2024).
- The Times, “NHS to launch £10.7 million trial of puberty blockers” (2024).
- Cass Review, Independent Review of Gender Identity Services for Children and Young People (2024).
- Ibid.
- Biggs, Michael. “The Tavistock’s Experiment with Puberty Blockers,” Journal of Sex & Marital Therapy (2020).
- Klink et al., “Bone Mass in Young Adulthood Following Puberty Suppression,” Journal of Clinical Endocrinology & Metabolism (2015).
- Hembree et al., “Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons,” Journal of Clinical Endocrinology & Metabolism (2017).
- Singh et al., “A Follow-Up Study of Boys with Gender Identity Disorder,” Journal of Sexual Medicine (2021).
- The Times, “Commission on Human Medicines advises against puberty blockers” (2024).
- Bell v. Tavistock, UK High Court Judgment (2020).
- Ministers Consultation Response, “Letter to the Secretary of State Opposing Gender Ideology in Law” (2021).
- PSHEbrighton, Supporting Families through Honest and Evidence-Based Education (2024).
- The Guardian, “Schools Using Gender Toolkit Risk Being Sued, Say Legal Experts” (2024).


































