Letter to the Faculty of Health Sciences, McMaster University

August 20, 2025

Letter to the Faculty of Health Sciences, McMaster University

We are writing in response to McMaster University’s Faculty of Health Science’s recent public statement about their “Systematic reviews related to gender-affirming care.” We are particularly concerned that this statement muddies the importance and implications of the Faculty’s own research.

The low and very low quality of evidence for so-called gender-affirming care and its efficacy has been repeatedly demonstrated. In 2020, reviews by the National Institute for Care and Health (NICE) ranked the quality of evidence for transition as “very low” in every category it examined. That same year, Finland’s Council for Choices in Health Care (PALKO/COHERE) determined that “in light of available evidence, gender reassignment on minors is an experimental practice.” In 2022, after a systematic review of the evidence, Sweden’s National Board of Health and Welfare (Socialstyrelsen) concluded that the risks associated with gender-affirming treatments outweighed the expected benefits in young people. In 2024, the U.K.’s Cass Review described an historical and ongoing “lack of high-quality evidence” to support gender-affirming interventions such as “puberty blockers and masculinising/feminising hormones.” In 2025, the U.S. Department of Health and Human Services (HHS) released its own review of evidence and best practices in the treatment of pediatric gender dysphoria. The HHS described the widespread “methodological and ethical deficiencies” in the standards of care guidelines used to treat young patients. They noted that “every public health authority that has conducted a systematic review of the evidence has concluded that the benefit/risk profile of [pediatric medical transition] is either unknowable or unfavorable.”

In this vein, the Faculty of Health Science’s reviews and meta-analyses broadly conform to the findings of a compelling and growing body of research. It is important that this scientific truth not be minimized or obscured because of political or social pressures.

Gender-affirming treatments are not neutral medical interventions. Gender medicine presupposes, without empirical evidence, the existence of an innate “gender identity” which can be incongruent with a person’s body. On this basis, healthy bodies are medicalized and pathologized. The gender-affirmation model strongly encourages the pursuit of irreversible pharmaceutical and surgical interventions in children, teens and vulnerable adults.  On the basis of very low quality evidence, healthy bodies are subject to permanent damage including, but hardly limited to, infertility, severe neuropathy, anorgasmia, urinary incontinence and premature osteoporosis.

The Faculty of Health Science’s public statement raises the specter of “limiting medical management options” for patients who experience discomfort with their sex. In fact, the dominant gender affirmation model is extremely limiting, insisting that the only medical management option available to patients is “medically necessary” social and physical transition. In practice, robust and comprehensive biopsychosocial diagnostic assessments are often dispensed with. The clinical rush to medicalize is often punctuated by grim (and mercifully false) predictions of the patient’s imminent suicide if transition is not pursued. It is imperative that patients be given honest and accurate information about the very low quality of evidence for these claims and for the efficacy of these treatments. Those seeking relief from discomfort with their sex must not be restricted to an empirically unevidenced affirmative model of care.

LGB Alliance Canada has an interest in the very low quality of evidence for gender-affirming care because we know that many young people who express discomfort with their sex are in fact lesbian, gay and bisexual youth who are conflicted about their same-sex attraction. When they are allowed to experience puberty without being steered toward unevidenced treatment pathways, this conflict and related cross-sex ideation almost always resolves itself in adolescence. Lesbian, gay and bisexual youth have the same right to a healthy puberty and to high quality, evidence-based medical care as their straight peers.

The 2025 HHS Review reminds us that the “principle of autonomy in medicine establishes a moral and legal right of competent patients to refuse any medical intervention. However, there is no corollary right to receive interventions that are not beneficial. Respect for patient autonomy does not negate clinicians’ professional and ethical obligation to protect and promote their patients’ health.” It is imperative that members of the academy engage in responsible, truthful and ethical science. The harmful, irreversible consequences of gender-affirming care do not leave room for scientists and academics to cavalierly disregard the very low quality of evidence for these treatments or to blindly promote unevidenced medical protocols.

Bernadette MacDonald

Scott Geiler

On behalf of
LGB Alliance Canada