The gist
New Zealand abandoned its public claim that puberty blocker drugs are “safe and fully reversible” because of the shift to greater medical caution in Europe, according to the NZ Ministry of Health.
“Health services in other countries [including the UK, Sweden and Finland] have been reviewing their guidance on use of puberty blockers, particularly in young people in the adolescent age group, and are calling for further research,” a spokesperson for the NZ health ministry told GCN.
The adoption of a more neutral reference to puberty blocker drugs on an NZ government webpage “reflected a clinically careful approach, while the evidence on safety and reversibility of puberty blockers is being reviewed, and in line with these other jurisdictions [overseas],” the spokesperson said last week, following renewed speculation about the reasons for the official change of position.
To explain its online self-correction, the NZ health ministry also cited “the relatively limited and thin evidence available in this area [of puberty blockers],” according to a March 24 report from the NZ media outlet Newsroom.
The ministry is due to release an “evidence brief” on blockers in May, Newsroom reported.
From 2017 until September 2022, the ministry’s webpage titled “Providing health services for transgender people” had claimed that, “Blockers are a safe and fully reversible medicine that may be used to help ease distress [accompanying the condition of gender dysphoria] and allow time to fully explore gender health options.”
Last September, without announcement, this confident claim was replaced with the more neutral statement that, “Puberty blockers are a medicine that can be used to halt the progress of potentially unwanted puberty-related physical changes.”
Reportage: When puberty blockers seem to make things worse
Insular news
Groups and individuals—including the LGB Alliance Aotearoa NZ and Simon Tegg of the gender clinic watchdog Fully Informed—had for some time been writing to alert the health ministry to tighter restrictions on youth gender medicine adopted or advised in Finland, Sweden and the UK. This shift to caution had been largely unreported by NZ media.
There is increasing international concern about the risks and uncertainties of hormone suppression drugs—known as gonadotropin-releasing hormone (GnRH) agonists or analogues—used off-label to interrupt the natural but unwanted puberty of children who do not identify with their biological sex.
Puberty blockers can be started as early as age 8-10 and are typically followed by cross-sex hormones to masculinise or feminise the body, with this regimen expected to result in adults who are sterilised and males unable to achieve orgasm.
“The most difficult question is whether puberty blockers do indeed provide valuable time for children and young people to consider their options, or whether they effectively ‘lock in’ children and young people to a treatment pathway which culminates in progression to feminising/ masculinising hormones by impeding the usual process of sexual orientation and gender identity development” — 2021 interim report from England’s independent review of youth gender dysphoria care led by paediatrician Dr Hilary Cass
Video: What is a woman? NZ prime minister Chris Hipkins, whose predecessor was female, is put on the spot
The detail
It’s not the first time that a health authority has quietly withdrawn a contentious claim about youth gender medicine—in June 2020 the UK National Health Service abandoned its public assurance that blockers were “fully reversible”—but NZ health ministry emails obtained under the Official Information Act give a rare insight into the process.
These email exchanges in August-September 2022 were the internal response to letters from members of the public—referred to as “consumers” by the ministry—targeting the “safe and fully reversible claim” as unsustainable given the results of systematic evidence reviews internationally.
The exchanges show that —
Medical and science officials in the ministry soon agreed there was cause to update the webpage reference, with the then chief medical officer, Dr Robyn Carey, noting on August 22 that, “Certainly the Swedish update is not in favour of using hormonal treatments in adolescents (I’ve not looked up the rest of the references yet).”
On September 5, deputy chief science advisor Dr Sayali Pendharkar—from the Evidence, Research and Innovation section of the ministry—suggested an evidence brief on puberty blockers should be prepared for publication on the ministry’s website.
She also suggested, “We should undertake a formal systematic review and meta-analysis on evidence-to-date on puberty blockers similar to [the] UK, Sweden, Finland.” [A systematic review is considered the most trustworthy way to assess the quality of evidence for treatment and represents a bigger undertaking than an evidence brief. The ministry did not answer GCN’s question last week whether NZ would carry out its own systematic review.]
On September 6, chief clinical advisor for child and youth health Dr Tim Jelleyman, a paediatrician, suggested the letter of reply to the consumers who had raised concerns about puberty blockers “should note we are amending the website information to reflect limits of evidence on reversibility [of blockers] and that further work to develop an evidence brief is planned.”
On September 8, senior advisor Jenna Osborne-Taylor, who is not medically trained, raised the issue of “the number of queries the college [of general practitioners and we of the primary care section] are receiving relating to puberty blockers.” [By this time, the outlines of the shift in position by the ministry had already been agreed by medical and science officials.]
On September 13, Osborne-Taylor said she hoped that a change in wording might lead to “fewer queries” and added that “while the statement [that blockers are safe and fully reversible] is no doubt true, as I’m sure you’re aware, there are both members of the public and medical professionals who disagree. [In the material seen by GCN, none of the medical or science officials defended the blockers claim as true.]
Osborne-Taylor was updated by Dr Jelleyman who remarked “it is right that we qualify the [puberty blockers] statement that is causing appropriate concern.”
Graphic: not all evidence is equal

Anti-trans bogeymen
“Health advice scrubbed due to anti-trans pressure” — that was the Newsroom headline for a March 24 article by NZ political journalist Marc Daalder purporting to explain why the “safe and fully reversible” claim had been abandoned.
The opening paragraphs read:
“Transgender health advice on the Ministry of Health website was ‘no doubt true’ but removed ‘in the hopes it creates fewer queries’, official correspondence reveals.
“Pressure from anti-transgender activists led the Ministry of Health to remove health advice regarding puberty blockers from its website in September [2022].
“While the ministry previously told media it had made the changes because it didn't want to provide specific clinical advice, correspondence released under the Official Information Act shows the webpage was actually edited ‘in the hopes it creates fewer queries’.”
The ministry’s account appeared at paragraph eight:
“The September 2022 update to the website recognised that overseas jurisdictions, including [the] UK and Sweden, were reviewing the use of puberty blockers in their health systems particularly in younger people,” [a ministry spokesperson told Newsroom].
“In light of the relatively limited and thin evidence available in this area, the ministry’s advice was changed to align better with that.”


Newsroom made selective use of Official Information Act material, specifically comments by the non-medically trained advisor Osborne-Taylor; the OIA material was freely available following a request by Fully Informed’s Simon Tegg.
Daalder also relied on Tegg’s November 2022 tweet that the ministry had at last abandoned its “safe and fully reversible [claim] after more than 50 people emailing them over the years and pointing out that this language was unfounded and misleading.”
Those 50-plus people—and Tegg, who was not named but was arguably identifiable—were portrayed in the Newsroom article as “anti-trans activists” who had successfully pressured the ministry into removing accurate information on puberty blockers.
As far as Tegg knows, most of these people had written to the ministry two years before it decided to update its website.
In Tegg’s opinion, the term “anti-trans” has been used to try to shut down good faith inquiry into youth gender medicine—inquiry motivated by concern for the welfare of vulnerable minors.
It’s possible readers may have inferred that Newsroom’s “anti-trans” epithet was meant to include two public health researchers who had each published an article in NZ media drawing attention to the puberty blockers controversy around the time when the ministry was workshopping its webpage reference to puberty blockers.
Newsroom revised the Daalder article after publication to clarify that concerns expressed by health professionals were not anti-trans.
This made the charge of anti-transness incoherent because the health professionals had raised exactly the same concerns as the unnamed “anti-trans activists”, according to Tegg.
“It’s just a sort of nebulous cloud of anti-transness floating around in the article, not specifying exactly who it is, because that would defame them,” he told GCN.
“During adolescence, the brain changes considerably. However, it is unclear whether the hormonal changes of puberty help to promote these changes or if this development occurs independent of our hormones. Related to this, we do not know whether using puberty blockers affects development of the brain” — 2022 invitation for adolescent patients to take part in a study of puberty blockers and brain function, Royal Children’s Hospital Melbourne gender clinic
‘No gay children left’
Tegg filed a request under the Official Information Act for copies of the consumer communications that led to the August-September 2022 flurry of emails within the ministry about how puberty blockers should be represented to the public.
The two letters supplied to him do not seem obviously anti-trans; this term is never clearly defined.
The first, sent in August 2022 to the then Health Minister Andrew Little, came from the LGB Alliance Aotearoa, which is part of a global network defending the interests of same-sex attracted people against gender ideology, in which a male can identify as a lesbian.
This letter cited the controversy over the world’s largest youth gender clinic, the London-based Tavistock Gender Identity Development Service (GIDS), where whistleblower staff had expressed concern that many of the gender non-conforming patients sterilised by hormonal treatment would have grown up as healthy lesbian, gay or bisexual adults, had they not undergone trans medicalisation.
“Comments by clinicians at GIDS have been recorded saying ‘soon, there will be no gay children left’ due to the excessive number of young people treated who would probably grow up to be LGB [lesbian, gay or bisexual],” the LGB Alliance letter said.
“We regard this as anti-homosexual conversion therapy by medical intervention … and would like confirmation that the same, or similar, is not happening here in New Zealand.”
The letter asked the health ministry to update its guidance on the risks of puberty blockers, to regularly audit NZ gender clinic records and carry out investigations “to ensure children are not being rushed into medicalisation prior to receiving in-depth, appropriate counselling.”
“Can you clarify whether MOH [Ministry of Health] believes [puberty blockers] are safe? I understand if you need to wait for emerging evidence, but some response would be useful given the misinformation and claims these right-wing anti-trans groups are spreading” — email to the ministry from journalist Rachel Thomas of the NZ media outlet Stuff, 22 September 2022, seeking comment on the updated webpage reference.
The second letter of concern to the NZ health ministry, with the identity of its author redacted, highlighted guidance from the government’s own regulator Medsafe that Zoladex (Goserelin)—an anti-prostate cancer drug used off-label as a trans puberty blocker—should not be given to children, and that another hormone suppression drug, Lucrin (Leuprorelin), was approved for children but only to treat precocious (or premature) puberty.
“There is no discussion of the treatment of adolescent gender dysphoria in the Medsafe guidelines,” the letter said.
It cited the 2021 systematic reviews by the UK National Institute of Health and Care Excellence, and the decision that same year at Sweden’s famous Karolinska university hospital to cease hormonal interventions as routine treatments for youth gender dysphoria following reports of harm to patients on puberty blockers.
“I am not opposed to transgender healthcare, I fully support appropriate healthcare for the appropriate people,” the letter writer said.
But the letter writer insisted that the ministry must first do its due diligence and “conduct its own independent review into the safety of puberty blockers without the conflict of interest of a quasi-medical/lobby group [such as the NZ Professional Association for Transgender Health Aotearoa].”
I don't think many mainstream journos -- and this applied to me too as a newspaper reporter -- are aware enough of the many competing sources of news & views available to everyday sceptical, curious people.
Excellent article! Again, thank you for this!