Health Minister Simeon Brown. Photo: RNZ / Mark Papalii
The government is halting new prescriptions of puberty blockers for young people with gender dysphoria, saying "a precautionary approach" is needed while evidence remains uncertain.
In a statement published on Wednesday afternoon, Health Minister Simeon Brown said Cabinet had agreed to the new settings until the outcome of a major clinical trial in the United Kingdom, expected in 2031.
The drugs - known as gonadotropin-releasing hormone analogues - would remain available for people already using them for gender dysphoria, as well as for medical conditions such as early-onset puberty, endometriosis, and prostate cancer.
Brown said the new rules - taking effect on 19 December - would give families confidence that any treatment was "clinically sound and in the best interests of the young person".
"These changes are about ensuring treatments are safe and carefully managed, while maintaining access to care for those who need it."
Existing youth gender services would stay in place, with information brought together into one national online hub, Brown said.
In a post on social media website X, New Zealand First leader Winston Peters said his party was the only one to campaign on stopping the use of puberty blockers in children.
"It is commonsense to put a pause on these unproven and potentially damaging drugs for children until we assess the results of the clinical trials in the UK once it's completed."
The ACT party's children's spokesperson Karen Chhour also issued a statement, declaring a victory for science, evidence, and the safety of children.
"I believe young people should be supported to love themselves, not change themselves with experimental medication."
Green Party MP Ricardo Menéndez March told RNZ the government was "buying into imported culture wars" and targeting trans people on the eve of Transgender Day of Remembrance.
"We know from queer people that gender affirming healthcare can be life-saving," he said. "The government should focus on addressing the core issues that our health system faces... rather than waging culture wars on trans people."
The coalition's move mirrors a major shift in the UK following the Cass Review - a four-year investigation commissioned by the National Health Service (NHS).
That review, spearheaded by paediatrician Dr Hilary Cass, concluded that the evidence base for gender-affirming medicine was "remarkably weak", with study results misrepresented by people on all sides of the debate.
Cass also recommended a formal clinical trial to properly test whether puberty blockers, which delay the onset of puberty by suppressing oestrogen and testosterone, were safe and effective for young people. That trial was due to run until 2031.
In response, the NHS stopped routine access to puberty blockers for new patients. Other countries, including Sweden, Finland and Norway, had already tightened access and guidelines.
The Cass Review split opinion among clinicians and academics worldwide. While some endorsed the call of higher evidence standards, others criticised the report's methodology and warned it downplayed the risk of denying treatment to young people.
At the time, the Professional Association for Transgender Health Aotearoa (PATHA) criticised the review as irrelevant to New Zealand and said it ignored the global medical consensus.
"The final Cass Review did not include trans or non-binary experts or clinicians experienced in providing gender affirming care in its decision-making, conclusions, or findings," PATHA president Jennifer Shields said.
"Instead, a number of people involved in the review and the advisory group previously advocated for bans on gender affirming care in the United States, and have promoted non-affirming 'gender exploratory therapy', which is considered a conversion practice."
Youth health specialist Dame Sue Bagshaw also said she believed puberty blockers were safe and reversible and warned against any "moral panic".
However, public health expert and Otago University emeritus professor Charlotte Paul said the British approach should give New Zealand clinicians "pause for thought", saying some had abandoned "normal standards of informed consent for children".
New Zealand's Health Ministry last year also released a report finding "a lack of high-quality evidence" on the benefits or risks of puberty blockers for gender dysphoria.
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