New Zealand’s ban will come into force in December (Wiktor Szymanowicz/Future Publishing via Getty Images)
New Zealand’s ban will come into force in December (Wiktor Szymanowicz/Future Publishing via Getty Images)
The New Zealand government has announced it is banning puberty blockers for transgender youth as it awaits the results of a major clinical trial in the UK – which are not expected until 2031.
The announcement means that, from 19 December, any new prescriptions of hormone suppressing drugs – known as gonadotropin-releasing hormone analogues – for the treatment of gender dysphoria will be halted.
However, the drugs will remain available to trans youth with existing prescriptions, and those who require them for the treatment of early-onset puberty, endometriosis and prostate cancer, or where “clinical evidence clearly demonstrates their benefit”.
On Wednesday (19 November) NZ’s health minister Simeon Brown wrote in a statement shared on X.com that the government is taking “a precautionary approach” and cited the UK’s controversial Cass Review as justification for the ban.
“When it comes to children’s health, clinical evidence must guide decisions to ensure any medicine given to young Kiwis is proven, safe and effective,” Brown wrote.
“The independent Cass Review, commissioned by the UK’s NHS, identified considerable uncertainty about the long-term safety and clinical effectiveness of hormone-suppressing treatments for gender dysphoria or incongruence. This wasn’t a political review, it was clinical.
“New Zealand’s own Ministry of Health reached the same conclusions in November 2024.
“Its evidence brief found significant limitations in the quality of evidence regarding both benefits and risks when hormone-suppressing treatments are used for the treatment of gender dysphoria or incongruence.”
Cabinet has agreed to restrict the prescribing of puberty blockers for patients seeking treatment for gender dysphoria or incongruence.
Let me explain the approach Cabinet has taken. 🧵
— Simeon Brown (@SimeonBrownMP) November 19, 2025
The 400-page Cass Review, a sweeping report into the provision of healthcare for trans youth in England, was published in April 2024 and made upwards of 32 recommendations to restructure the way trans youth receive care.
One of the recommendations included exercising “extreme caution” on the use of puberty blockers.
In response to the report, the former Conservative government’s enacted a ban on private prescriptions for puberty blockers for trans youngsters, which was continued by Labour following the general election in July 2024. In December, the ban was extended indefinitely.
The Cass Review and its methodology has been been subject to scrutiny by charities, not-for-profit groups, medical organisations and academics, including the British Medical Association, who have labelled it “deeply flawed” and claimed it relied on a “selective and inconsistent use of evidence”.
In May, a publicly funded, £10 million NHS trial into the use of puberty blockers, led by researchers at King’s College London, was launched. The trial will see trans youngsters given puberty-blocking treatments and their physical, social and emotional well-being analysed.
In his statement, Brown went on to say that NZ’s Cabinet had “decided to align our approach with the UK” and would wait for the trial’s “clinical evidence before reconsidering any decisions”.
“Cabinet has put in place stronger safeguards so families can have confidence that any treatment is clinically sound and in the best interests of the child,” he concluded.
“Banning their use will lead to profound distress”
In response, the Professional Association for Transgender Health Aotearoa (PATHA) condemned the decision and said it would leave trans youth at risk of deep distress.
“The ban will lead to a deterioration in mental health, increased risk of suicidality and increased dysphoria in gender diverse children and young people, and will put them at a higher risk of experiencing marginalisation and discrimination,” Dr Elizabeth McElrea, GP specialist in gender affirming care and PATHA Vice-President, said in a statement.
“The prescribing of puberty blockers is always undertaken with the utmost care and consideration.
“They have been prescribed safely for decades for transgender children and banning their use will lead to profound distress in this already vulnerable group.”
McElrea continued: “PATHA supports evidence-based medicine, which consists of three key components: academic evidence, clinical experience, and patient preferences and values.
“When the quality of available academic evidence is of lower quality, it’s incredibly common for clinicians to lean on guidelines drawn from clinical experience.”
“Practising medicine, and paediatric medicine (not just within gender affirming healthcare), often necessitates providing care without a high-quality evidence base. The absence of high-quality clinical evidence does not mean providing this care is wrong.”