They can also reduce the need for later interventions such as hair removal, voice therapy or chest surgery. If treatment stops, puberty resumes – a key reason they are considered an appropriate early intervention in international clinical guidelines.
The Government has framed its decision as a “precautionary”, citing England’s Cass Review, which emphasises the need to see mental health improvements before allowing these medications to continue to be used.
This reflects a fundamental misunderstanding of what puberty blockers are designed to do.
Puberty blockers are not a mental health treatment and are widely accepted as effective at their actual purpose: pausing unwanted physical changes.
They do not themselves change the body in ways that affirm a person’s gender. Any mental health benefit is secondary and shouldn’t be the central measure of whether they work.
Despite this, reviews like Cass still call for mental health improvements, repeating an outdated framing that assumes gender-affirming care is about treating a mental health condition.
It is also important to note that evidence for mental health outcomes is contested rather than lacking – and many other paediatric treatments continue to be used despite having similarly limited or even weaker evidence.
Why the evidence doesn’t support a ban
The claim that puberty blockers have a “lack of high-quality evidence” could be misleading to anyone who is not aware of the full context.
It could apply to many areas of young people’s healthcare, including widely accepted interventions.
A large proportion of medications used in children – such as commonly prescribed antidepressants and increasingly prescribed ADHD medication – lack high-quality evidence about long-term developmental impacts.
Even treatments for precocious puberty, which use the very same puberty blockers, have limited long-term data on psychosocial outcomes. In all these cases, the safety profile is considered acceptable, and no one demands high-certainty mental health evidence for their use.
The Government has placed a burden of proof on puberty blockers that we do not place on other paediatric care.
Proponents of the ban have stated that other types of paediatric care have adult data to draw from. The concern raised about puberty blockers, however, is specifically about impacts during a critical developmental period (puberty), so adult safety data couldn’t address this for any paediatric medication.
The Government also notes that puberty blockers are “not currently approved by Medsafe for use in [gender-affirming care]”. But again, they don’t provide the context that off-label use is routine and accepted across medicine.
Many medications used for children are prescribed off-label because regulatory processes often lag behind clinical practice.
A glaring inconsistency
Puberty blockers will remain available for children with precocious (early) puberty, who are typically younger than those receiving them for gender-affirming care.
The Government has offered no evidence showing that the risks differ meaningfully between these groups. That inconsistency alone raises serious questions about whether this decision is grounded in evidence or ideology.
The Ministry of Health’s puberty blockers evidence brief did not identify evidence of harm that would justify a ban on using puberty blockers for gender-affirming healthcare.
By contrast, the risks of withholding this care – forcing young people through a puberty they cannot stop or reverse – are clear and significant.
And while the Government notes it is aligning with the UK, there is a broader international context. Restrictions on puberty blockers have emerged in Great Britain, parts of Scandinavia, Queensland in Australia and some US states. But these have occurred in a context of political pressure and culture-war dynamics, rather than by any new medical evidence.
Meanwhile, most comparable countries – including most of Australia, Canada, much of Europe, and leading international medical bodies – continue to endorse puberty blockers as standard care.
The Government also cites its public consultation, but public views cannot replace clinical expertise.
Politicised healthcare?
The voices that matter most – trans young people, their families, the clinicians who work with them and trans health experts in Aotearoa – have been clear: access to puberty blockers is crucial.
These voices appear to have been ignored. When complex medical decisions are shaped by public polling rather than the needs of patients and their families, healthcare is being politicised rather than protected.
At its heart, the issue is simple: puberty blockers have been used safely for decades and there is no evidence of harm that would justify banning them for gender-affirming care.
The decision to restrict access specifically for gender-affirming care, while allowing the same medicines for other uses, is inconsistent and may be discriminatory.
And the implications extend beyond trans young people. When governments override established clinical practice without evidence, and when minority groups become targets of restrictive medical policy, it sets a precedent that should concern everyone.
