We don't know enough yet about how puberty blockers and hormone treatments effect young bodies. It is too risky currently to allow trans children and adolescents to medically transition.
The argument
Though puberty bockers have a significant history of usage, they are only technically approved by the FDA for treating children who begin puberty too early and have not been approved for treating transgender children. Additionally, there has been little research done on children who take the medication for extended periods of time, etc. One study found that puberty blockers can result in a decrease in bone density, though researchers are unsure if this decrease can be reversed once the child stops taking puberty blockers. Initial studies seem to suggest that starting estrogen or testosterone can help regain bone density, but are inconclusive on whether they can fully reverse the damage done. Another issue is that we don’t know how much pubertal hormones impact brain development in adolescence. Hormone treatments (such as transgender girls taking estrogen) also pose their own risks. Patients who undergo hormone treatment may be at higher risk of developing heart disease, diabetes, and blood clots in the future. Hormone treatments can also reduce fertility. In response to this risk, many adults store their eggs or sperm before starting hormone treatments. However, transgender children may be too young for that process, so they do not have that “back-up plan” in the case that they are rendered infertile. Though these risks are often taken by informed adult patients, since they are not overwhelmingly high, allowing children to take these risks is a completely different story. For instance, we allow adults to drink alcohol and smoke cigarettes knowing that there are high risks associated with these behaviors, but we would never let children take those same risks. In a similar way, even though transgender adults make take on the risks associated with medical transition, transgender children should not be allowed to take those risks because they cannot be expected to understand what those risks entail and they are not cognitively developed enough to make that decision.
Premises
Counter-arguments
Defenders of youth gender-affirming care argue the risks must be weighed against the harms of withholding treatment, not considered in isolation. Major medical associations that endorse such care point to evidence that, for carefully assessed adolescents with persistent dysphoria, treatment is associated with reduced distress, depression and suicidality, and they contend that denying care is not a neutral, risk-free option but one with its own serious harms. Puberty blockers, on this view, are longstanding medications used to pause puberty and buy time for assessment, with much of their effect (including on bone density) intended to be temporary, and hormone therapy is provided under supervision with staged, informed consent involving clinicians and parents. Critics of the argument also challenge the alcohol-and-smoking analogy: those are unsupervised recreational choices, whereas transition is monitored medical care with diagnosis, consent processes and the involvement of families and specialists, and decisions about fertility and long-term risk are discussed as part of that care rather than left to a child alone. They acknowledge the evidence base is debated and still developing — some jurisdictions have tightened protocols pending review — but argue that uncertainty is a reason for careful, individualised assessment, not a blanket prohibition that forecloses treatment for those it could help.
Rejecting the premises
[Rejecting P1] Critics note puberty blockers are used precisely to pause puberty during assessment and that effects such as reduced bone density are considered largely reversible; supporters weigh these risks against the documented distress of untreated dysphoria. [Rejecting P3] They dispute the alcohol/smoking analogy: transition is supervised medical care with diagnosis, staged informed consent and family and clinician involvement, not an unsupervised recreational risk, so 'children cannot choose' does not map onto a monitored clinical process. [Rejecting C] Weighing risks in isolation ignores the harms of withholding care; critics argue uncertainty warrants careful individual assessment rather than a blanket ban that forecloses treatment for those who would benefit.