By Mia Hughes, February 5, 2025
A team of Canadian researchers found that the evidence for the use of puberty blockers and cross-sex hormones for adolescents identifying as transgender is of “very low certainty.” The two new analyses, conducted by McMaster University, are being touted as the most “methodologically rigorous systematic reviews” of the evidence for paediatric gender medicine to date. But in truth, we don’t need any more systematic reviews of the evidence for puberty suppression in adolescents who identify as transgender. That the evidence in favour of puberty blockers and cross-sex hormone use for minors is weak and unreliable has been demonstrated beyond doubt time and time again.
The Canadian findings echo the conclusions of every other systematic review of the evidence in this field. The McMaster analyses, led by Dr. Gordon Guyatt, the “godfather of evidence-based medicine,” follow closely on the heels of the landmark Cass Review – a comprehensive four-year investigation into the UK’s youth gender service, supported by extensive systematic evidence reviews. Dr. Hilary Cass, former president of the Royal College of Paediatrics, led the review and concluded that the evidence supporting puberty blockers and cross-sex hormones is “remarkably weak.” As a result, the United Kingdom imposed an indefinite ban on the use of these drugs outside of clinical trials.
The conclusion of the Cass Review aligned with earlier reviews by England’s National Institute for Health and Care Excellence (NICE) in 2020, which assessed the evidence as being of “very low certainty.” Reviews conducted by Sweden, Finland, Germany, Florida, and even the World Professional Association for Transgender Health (WPATH) all reached similar conclusions, agreeing that the quality of evidence is very low, making it impossible to assert confidently that these experimental treatments are either safe or effective. This repeated examination of the same evidence, yielding the same results, makes the latest effort seem redundant, rather like reinventing the wheel.
As the saying goes, insanity is doing the same thing repeatedly while expecting different results. However, applying this to the McMaster team is both unfair and inaccurate. These reviews were years in the making, and it’s reasonable to assume that no one on the team expected different results to those already published. Instead, it is the stubborn refusal of Canadian medical institutions, and the broader field of gender-affirming medicine in North America, to respect the basic principles of evidence-based medicine that has compelled some of the world’s top medical experts to simultaneously pour valuable time and resources into research with conclusions that were already known from the outset.
Conspicuously missing from the scientific literature assessed by the McMaster review is research into the potential harms associated with blocking puberty and administering cross-sex hormones to young people. This omission is not the fault of Guyatt and his team; it’s because such studies don’t exist due to an astonishing lack of follow up in the field of gender-affirming care. Researchers in this area show little interest in monitoring the long-term effects or potential harms experienced by the young participants of this reckless medical experiment.
This is particularly alarming given the well-documented risks of this treatment protocol: the health consequences of early menopause, the dangers of prolonged cross-sex hormone use, the high complication rates associated with genital surgeries, and the significantly elevated risk of suicide among adults who have undergone full medical transition. Indeed, the only correlation Guyatt’s team found to be of “high certainty” was research showing an association between cross-sex hormone use and cardiovascular events.
Another recent study out of the UK provided yet more information that has been common knowledge for years. It showed that the number of children and adolescents diagnosed with gender dysphoria has risen fifty-fold over a decade. Again, while valuable, this is not new information. Evidence of the epidemic of young people identifying as transgender across the entire industrialized world has been abundant since at least 2020. Keeping abreast on the developments in this field is starting to feel a lot like Groundhog Day.
What we urgently need is research that addresses the core issue: why are so many young people suddenly identifying as transgender and pursuing unproven, potentially life-altering medical interventions as a result? We need to study mass social media induced illnesses and the mechanisms by which this social contagion is spreading. We need a serious discussion about the validity of gender dysphoria as a diagnosis and recognition that it has been crafted by trans activists, not medical experts, and rendered almost completely meaningless through misuse.
We also need research into the harm of blocking the crucial developmental stage of puberty, the long-term health risks of placing adolescent girls into early menopause, and the dangers of extended use of wrong-sex hormones in young people. Above all, we need the entire field of gender medicine in North America to purge itself of activists who prioritize politics over patient health and ideology over evidence. To protect the young people swept up in today’s transgender craze, we don’t need more systematic reviews. We need a bold revolution, and we need it without delay.
Mia Hughes specializes in paediatric gender medicine, psychiatric epidemics, social contagion, and the intersection of trans rights with women’s rights. She is the author of The WPATH Files and a senior fellow at the Macdonald-Laurier Institute.
