On 19 November Minister of Health Simeon Brown announced that the Government had introduced a ban, from 19 December, on new young patients being medically prescribed puberty blockers in order to delay puberty in cases of gender dysphoria or incongruence.
The ban is for at least five years (possibly longer). A narrowly focussed clinical trial on puberty blockers in the United Kingdom is scheduled to be completed in 2031.
Gender incongruence is marked and persistent experience of incompatibility between a person’s gender identity and sex at birth. Gender dysphoria is discomfort or distress related to this incongruence.
Trans youth already using this medication will be able to continue to access puberty blockers. The ban doesn’t apply to non-trans young people experiencing things like early onset puberty, endometriosis, or prostate cancer.

Health Minister Simeon Brown’s announced ban meant the rejection of Health Ministry advice
This decision was a rejection of the published ‘evidence brief’, in November 2024, of the Ministry of Health which advised that puberty blockers should only be prescribed by a clinician experienced in gender affirming care, and supported by an interprofessional team including mental health support.
The Ministry drew upon the Cass Review (discussed below) in developing its advice. I discussed this thoughtful advice in an earlier Otaihanga Second Opinion post (7 January): Welcome advice but beware of derailing transphobia.
The transphobic politics behind the ban
The politics behind Simeon Brown’s effective rejection of this advice decision were quickly revealed.

Casey Costello indirectly confirmed transphobic bigotry politics behind the ban
Minutes after his announcement New Zealand First’s leader Winston Peters and its associate health minister Casey Costello issued media statements claiming (gloating is another name for it) that the ban was their political win.
In Costello’s words:
It’s a win for sanity in the “war on woke”. After years of dangerous ideological experimentation pushed by radical activists and rubber-stamped by weak politicians, the New Zealand Government has officially banned puberty blockers for children. This is what happens when you back a party that actually delivers.
It’s a monumental victory for common sense and for every parent who’s been told to sit down, shut up, and let so-called ‘experts’ chemically sterilise their kids because they were ‘born in the wrong body’. No one is born in the wrong body.
NZ First is proudly transphobic and all of the phobia’s associated bigotry. Perhaps this is why the ban was announced on Transgender Day of Remembrance!
In my above-mentioned blog post on the Health Ministry’s advice I warned against decision-making being influenced by transphobia. It hasn’t been; instead it has been determined by it.
The Cass Review
The Cass Review chaired by Dr Hilary Cass was established by the British government to independently review gender-related stress services for children and young people.
This was influenced by what is known as the ‘Tavistock scandal’, a distressing experience of zealousness affecting these services, particularly in respect of puberty blockers.
In my view it is a credible peer reviewed report which helped shape the above-mentioned Health Ministry advice. Unfortunately it is also being used by some to rationalise transphobic decision-making.

Eminent paediatrician Dr Hilary Cass chaired the independent review
In respect of puberty blockers the peer reviewed Cass Review noted with concern that:
… systematic evidence reviews demonstrated the poor quality of the published studies, meaning there is not a reliable evidence base upon which to make clinical decisions, or for children and their families to make informed choices.
Further:
The strengths and weaknesses of the evidence base on the care of children and young people are often misrepresented and overstated, both in scientific publications and social debate.
The controversy surrounding the use of medical treatments has taken focus away from what the individualised care and treatment is intended to achieve for individuals seeking support from NHS gender services.
The rationale for early puberty suppression remains unclear, with weak evidence regarding the impact on gender dysphoria, mental or psychosocial health. The effect on cognitive and psychosexual development remains unknown.
…For the majority of young people, a medical pathway may not be the best way to manage their gender-related distress. For those young people for whom a medical pathway is clinically indicated, it is not enough to provide this without also addressing wider mental health and/or psychosocially challenging problems.
The Review took a balanced approach to the challenge of using puberty blockers safely:
Innovation is important if medicine is to move forward, but there must be a proportionate level of monitoring, oversight and regulation that does not stifle progress, while preventing creep of unproven approaches into clinical practice. Innovation must draw from and contribute to the evidence base.

Cass Review consistent with Hippocrates’ Hippocratic Oath
I discussed the Cass Review in Otaihanga Second Opinion (30 August 2024) regarding its analysis as credible and consistent with the first principle of the Hippocratic Oath, ‘first do no harm’: Puberty blockers and the Hippocratic Oath.
Listen to the clinical experts
The Science Media Centre was established in 2008. It is funded by the Ministry of Business, Innovation and Employment (MBIE) as part of the National Strategic Plan for Science in Society. One of its roles is to provide expert advice to journalists on scientific issues.

Science Media Centre has published clinical expert reactions to ban
On 21 November the Centre published expert reactions to the Government’s decision to ban new puberty blocker prescriptions for youth with gender dysphoria.
Dr Ben Albert is a paediatric endocrinologist at Starship Children’s Hospital and also a senior research fellow at Auckland University’s Liggins Institute.

Dr Ben Albert: An outright ban is not justified by the state of the science
In his words:
This is a disappointing decision. The young people seeking help for gender dysphoria are deeply distressed by the changes occurring to their bodies in puberty because their bodies irreversibly change towards a sex they don’t identify with. Puberty blockers halt that process, and give the young person time to age without those changes and work out what they want to do as they get older and are able to make more decisions for themselves.
I think there is a need to be cautious about how we provide gender affirming care. We need to be generating more evidence to find out which young people benefit the most from treatment, which ones are less likely to. We need to very carefully inform patients about the effects of these medicines, and continually check in with them about whether they still want to take them. We need to make sure that next steps, like hormone therapies, are treated not as inevitable, but as another important decision to be made. But none of that means that we shouldn’t be offering treatment to young people now.
The Cass report emphasised that there is limited high quality evidence in the area of gender affirming care, especially the type that comes from randomised controlled trials. This is important and there is a need for more research to help guide the best way to offer treatment, as there is in many aspects of medical care, especially for children and young people. However, we already know a huge amount about the effects of puberty blockers, we know what these medications do and how to use them safely. An outright ban is not justified by the state of the science.
Puberty blockers are generally very safe medications. When used, they stop the hormonal messages from the brain that cause puberty to occur and progress. When they are stopped puberty restarts. Taking them for a long time in adolescence can lead the person to accrue less calcium in their bones, than they otherwise would have, so that there might be an impact on fracture risk when they are older. These are the sorts of things that young people should be informed of when they make decisions about puberty blockers, but not a reason not to use them at all.

Dr Rona Carroll: Prescribing decisions should remain between clinicians, patients and their whānau
Dr Rona Carroll is a general practitioner with experience in transgender health as well as a senior lecturer at Otago University.
In her words:
The Government’s announcement that new patients seeking treatment for gender dysphoria or incongruence can no longer be prescribed gonadotropin-releasing hormone (GnRH) analogues from December 19th is a shockingly inappropriate overreach of politics into healthcare. Prescribing decisions should remain between clinicians, patients and their whānau.
GnRH analogues are used by a very small number of young people to prevent irreversible and distressing bodily changes. They are prescribed with great care by interdisciplinary teams with expertise and experience in providing healthcare for young people experiencing gender incongruence and distress. Their use is supported by major medical bodies including the Endocrine Society and the Royal Australasian College of Physicians.
There is evidence to show the benefits of GnRH analogues for people experiencing gender incongruence, however, the challenges and ethical considerations of conducting randomised controlled trials in this field mean that the available evidence has limitations. This is common in many areas of medicine, particularly paediatrics and is not unique to transgender healthcare. Other medications with similar levels of evidence continue to be prescribed. No other area of paediatric medicine is held to this standard.
The Government media release states that “Cabinet has agreed that the Ministry of Health will review the settings for the prescribing of gonadotropin-releasing hormone analogues for the treatment of gender dysphoria or incongruence once the results of the United Kingdom clinical trial are available.” The UK trial is expected to run until 2031, and then there will presumably be a considerable time until the results are published. Whilst the results are likely to be helpful and will add to the body of existing evidence, there is no justification to ban this care while they are being awaited.
The UK clinical trial will only monitor young people on GnRH analogues for 2 years. It is hard to see what evidence this will provide that is not already available. The benefits of preventing an unwanted puberty may not be seen for many more years as people grow older and go into adulthood. Given that GnRH analogues are often initiated at the start of puberty, after 2 years on this medication patients will not yet have experienced the benefits of preventing unwanted physical changes in adulthood. The more longitudinal arm of the UK study is observational, so will also not provide the high-quality level of evidence which the Government claim is needed.
The Government announcement states that GnRH analogues can still be prescribed for other indications. This ban only applies to those being prescribed GnRH analogues for gender incongruence or dysphoria. This discriminatory approach shows that this decision isn’t about medication safety concerns but instead is politically motivated to prevent transgender people from accessing gender affirming medical care. Health professionals have decades of experience in using these medications. There are no concerns around the reversibility or safety of these medications when they are used in these other situations.
When considering the balance of the potential benefits and low level of identified risks, banning GnRH prescribing for people experiencing gender incongruence or dysphoria is unjustified, unethical and cruel.
If the wellbeing of children and young people was truly at the heart of this, the Government would be supporting accessible, high-quality healthcare, and support for young people and their families to make their own informed decisions about their body and their health with the support of experienced healthcare professionals. Young people have a right to access the healthcare they need.

Professor Paul Hofman: a lack of understanding about the impact their decisions can have on vulnerable groups
Professor Paul Hofman is a paediatric endocrinologist at Auckland University.
In his words:
With the latest banning of pubertal blockers in transgender youth, the Minister of Health and his advisors have demonstrated a lack of understanding about the impact their decisions can have on vulnerable groups.
In this instance the Government media release states “Cabinet has agreed that the Ministry of Health will review the settings for the prescribing of gonadotropin-releasing hormone analogues for the treatment of gender dysphoria or incongruence once the results of the United Kingdom clinical trial are available.” As Dr Rona Carroll elegantly summarised – this is NOT a study that will answer the questions the current government are asking. It is a longitudinal study following individuals with transgender over a very short period of 2 years. It cannot answer the questions of pubertal blockers safety or efficacy – the two main issues raised. So waiting for another 6 years for study results that will be non-informative can only be seen as cynical politics. Moreover, when is a UK study an appropriate guide for New Zealand which has a very different cultural mix? Both Māori and Pacific peoples in particular have a more permissive approach to transgender and sexual diversity. We should not be taking guidance from a substandard, qualitative UK study which has minimal relevance to New Zealand and our cultures.
Let us look at the data on that are available. Pubertal blockage has been used in medicine for over 40 years (1979) and their safety and efficacy in blocking puberty is well established. They have been used in adults for treating breast and prostate cancer and are used in paediatrics to block precocious (abnormally early) puberty and used to increase final height in short children by delaying puberty and increasing the time available to grow. Some experts are concerned that blocking puberty for 3-4 years in early adolescence changes gender identity and causes or worsens transgender feelings. There is NO data to support this assertion. In no situation in paediatrics, including the use of pubertal blockers for several years in early adolescence to increase final height has gender dysphoria been an issue/reported. Similarly, there are many children who have delayed puberty and in some societies, a failure to go into puberty is not identified until early adult life (ie no gonadal sex hormones are present). In none of these situations has gender dysphoria been reported. Gender identity is usually in place in early childhood and not related to sex steroid hormones after birth. Therefore, how would one hypothesize that delaying puberty by 3-4 years is going to change one’s gender identity? The proposal has no basis in our understanding of gender identity nor any scientific evidence to support it.
What will happen though is, in those youth with gender dysphoria who don’t receive puberty blockers, there will be greater conflict, self loathing and mental health issues including anxiety and depression. Bulling, self-harming and suicidal ideation have been associated with being transgender and gender diverse. Indeed, access to pubertal blockade has been shown in one cross sectional study to reduce the risk of life-time suicidal ideation by 60%.
Sadly, in my opinion, this decision is not based on medical expertise or science and appears to be a transphobic, politically driven response. My questions of the Minister and his advisors though, is when the levels of self-harm and suicidal attempts increase, as is likely the case, will they take responsibility for the consequences of their actions?”

Dr Massimo Giola: I’m really worried that this seems to be a purely political decision without any consultation with experts
Dr Massimo Giola is a sexual health physician. Although he doesn’t prescribe puberty blockers, he does provide gender affirming care.
In his words:
In my work, I see gender diverse youth after the age of 16. I am very worried about the state of their mental health at that point, and I’m worried that they might have significantly self-harmed because of allowing biological puberty to happen, rather than pausing it using these medications.
While these medications were never subject to a randomized control trial, that is the case for many other interventions in medicine, and particularly for young people, when it’s really, really hard to perform a 100% ‘scientific’ randomized, controlled trial.
The announcement was essentially a big surprise that we did not see that coming yesterday. There is no reference to any consultation with professionals in the press release I see. And so I’m really worried that this seems to be a purely political decision without any consultation with experts. I would really like to ask the question: what kind of consultation was undertaken before reaching this decision? Particularly because there was a technical report provided by the officials at the Ministry of Health to the minister. The recommendation in that report was that the prescription of puberty blockers should happen in a multidisciplinary context, with the involvement of all the relevant professionals, including mental health professionals. What happened to that advice?

Dr Sue Bagshaw: to ignore the protective effect on mental health is not a safeguard
Dr Sue Bagshaw is a senior clinical lecturer at the Christchurch School of Medicine (Otago University) and a retired general practitioner with much experience in sexual and youth health.
In her words:
I am saddened to hear of more problems with assisting young people with the help they need to have time to work through the issues they might have with gender identity.
Safeguards are important but to ignore the protective effect on mental health is not a safeguard.
Resources to undertake research into the effects of gonadotrophin releasing analogues would be welcome and necessary before any further actions from the government are undertaken.
Now listen to the professional medical colleges
On 21 November the College of Psychiatrists President Dr Hiran Thabrew highlighted the point that the ban could harm vulnerable young people.

Dr Hiran Thabrew: vulnerable people should be protected from the ban’s harm
He also pointedly noted that that the announcement had been made on the Transgender Day of Remembrance.
Further this was now a “time of uncertainty” for many including trans and gender-diverse people. They needed to be protected from harm.
The College of Public Health Medicine, on 24 November, described the ban as “inappropriate”.

Dr Collin Tukuitonga: could cause significant additional harm
College President Sir Collin Tukuitonga said that:
Removing this treatment option could cause significant additional harm to the mental health of young people with gender incongruence and dysphoria.
While the College acknowledges that the evidence base for such prescribing is limited, the ban represents political overreach and appears to be more about ideology than science.
… governments of the day shouldn’t be making decisions on what treatments should or should not be prescribed, or what indications or patient groups are appropriate to receive such treatments.
These are clinical decisions that should be made by medical specialists with appropriate expertise working within their scopes and with multidisciplinary teams in partnership with patients and their families.
The College is also concerned that the Government’s ban appears to have been made without meaningful consultation with the community that will be most impacted. Trans and gender-diverse people experience higher rates of mental illness due to discrimination, stigma, trauma and abuse. They must be consulted before regulations that directly impact on their healthcare are put in place.

Dr Prabani Wood: GP College Medical Director concerned about political intervention in a medical matter
On 25 November the Medical Director of the College of General Practitioners, Dr Prabani Wood, said:
The College was not consulted about this announcement prior to its release, and we have yet to be informed about the alternative treatment and support options for patients who come to us after these changes come into effect on 19 December 2025.
We are also concerned that this announcement by the Minister represents political intervention in a medical matter.
Patients deserve to have politics out of clinical decision-making
Banning puberty blockers for young people with gender dysphoria or incongruence is a blatant interference in clinical decision-making.
These young people are patients. Like all other patients they are entitled to have clinical decisions made by clinical experts.
Like all other patients they should not have their clinical decisions made by politics. In this case the politics are driven by bigoted transphobia.
Like all other patients they are entitled to be treated in accordance with the Hippocratic Oath. Both the Cass Review and Ministry of Health’s advice were consistent with this Oath. Unfortunately, however, these young patients are being denied the Oath’s first principle of ‘first do no harm’.
Surely clinical decision-making for these young vulnerable patients is not too much to ask for. Unfortunately political decision-makers think otherwise.
I’ll leave the final comment to Dr Collin Tukuitonga in his above-mentioned College statement:
For the Minister to cite a ‘precautionary approach’ as the basis for the ban is disingenuous and ironic… health experts have been crying out for the Government to adopt a precautionary approach to address a range of public health challenges, but such calls have gone unheeded, even when there is robust evidence to guide policy.
Ian Powell was Executive Director of the Association of Salaried Medical Specialists, the professional union representing senior doctors and dentists in New Zealand, for over 30 years, until December 2019. He is now a health systems, labour market, and political commentator living in the small river estuary community of Otaihanga (the place by the tide). First published at Otaihanga Second Opinion.



Thank you Ian for your thought provoking and informative article. Off course these difficult situations should always be decided by the individuals concerned, their family and their medical advisors-acting on the best scientific/medical evidence available. Not Politicians.
Would freedom of clinical decision making logically extend to FGM, sex-selection abortions, or euthanasia?