The initial Cass Review sent reverberations around the world. What kind of effect has it had a couple of years out?
We see several themes in 2026 that reflect a shift toward greater caution, additional evidence requirements, or restrictions around medical/social transition for minors. Healthcare systems are continuing to try to juggle competing interests from activist groups but there is a clear pivot to more evidence-based care for youth – or at least the appearances of such. Given the highly controversial nature of medical gender transition, it is unlikely that science and evidence will overcome ideology and emotion. Nonetheless, it is the responsibility of public healthcare systems to ensure medical interventions do not cause harm and that the benefits of treatments must clearly outweigh the risks. This is the primary question we believe needs to be addressed. Some countries around the world have taken steps down this path.
1. UK: NHS moved from restricting puberty blockers to reassessing hormones as well
The UK remains the most influential example of a country shifting from an “affirm first” model toward a more evidence-review model.
Following the NHS England changes after the Cass Review, routine puberty blocker prescribing for gender dysphoria in under-18s was stopped outside research settings. The rationale was that the evidence base was insufficient to establish clear benefits and risks.
More recently, NHS England began reviewing whether masculinising/feminising hormones should remain a routine treatment option for adolescents, citing uncertainty about the evidence for benefits and harms in young people.
A key shift is that the question is no longer only “how should access be provided?” but “does the evidence justify routine medicalization of minors at all?”
2. UK puberty blocker clinical trial: the emphasis moved from treatment to evidence generation
A major consequence of the evidence debate has been the decision to study puberty blockers more rigorously rather than continue broad clinical use.
The proposed NHS trial intends to address unanswered questions about outcomes, including psychological effects and longer-term impacts. The Cass Review’s central criticism was that existing evidence was too weak to confidently determine whether puberty suppression improves outcomes for young people with gender dysphoria. There is still much concern about the ability for minors to consent to such a life-altering experiment and the ethical questions this trial exposes cannot be justified for many. There is significant concern about the short monitoring timeframe because this trial may simply reveal a “honeymoon” effect from puberty blockers rather than accurately assess the outcomes and risks over time. Regardless, the shift in the UK is one from puberty blockers on demand to this model where some oversight will be built in.
3. Australia: increased scrutiny and state-level restrictions
Australia has become one of the next major areas of debate. A national review of gender affirmation treatments and proceedures was launched in 2025. An interim report and initial public consultation process should be coming soon. There’s much concern about whether the group conducting this review has a balanced and unbiased perspective.
Some Australian jurisdictions have introduced restrictions or reviews, citing uncertainty about long-term evidence. Queensland extended restrictions on puberty blockers and early hormone treatment for minors while awaiting further evidence. The debate there has increasingly focused on whether existing international evidence reviews (particularly from the UK, Sweden, and Finland) should influence Australian practice.
4. Professional organizations: more emphasis on uncertainty and careful selection
Even among organizations that continue supporting access to care, there has been increasing acknowledgement that the evidence base for adolescents is limited.
This does not represent a universal agreement that medical transition is ineffective; rather, the point of contention has increasingly become whether the certainty of benefit outweighs uncertainty about risks.
5. Broader international trend: “affirmation-only” models are being reconsidered
A notable global pattern is that several European countries that previously had more permissive approaches have moved toward: psychological assessment, multidisciplinary review, limiting routine puberty suppression, prioritizing research settings.
The common justification has been not hostility toward transgender people, but concern that the evidence for adolescent medical interventions has been weaker than expected for treatments with potentially lifelong consequences.
How about Canada?
Unfortunately, Canada and Europe show a stark divergence in treating gender-distressed youth: Europe has shifted toward extreme caution and clinical restrictions, while Canada largely maintains its permissive, mainstream gender-affirming care model supported by national and provincial medical bodies. The notable exception is Alberta, where puberty blockers and other medical interventions for gender transition of minors are restricted.
The Canadian Paediatric Society, for example, appears to be bucking the international trend toward more caution by appointing Dr Natasha Johnson as the President. She was one of the lead authors on the CPS position statement in support of gender affirming care. We continue to hope that the CPS is open to an evidence based review of care models. Canadian children deserve to have access to a healthcare system that helps them thrive, not one captured by ideological positions that exposes them to needless harms.
