Transgender Youth and Puberty Blockers: Cutting Through the Controversy
What does the evidence tell us— and what do transgender youth and their families say?
There is perhaps no aspect of gender-affirming care that garners more attention than the use of puberty blockers.
They are described as ‘experimental’ and ‘controversial’ by those opposed to their use.
They’ve been banned in several U.S. states, and their use limited to “exceptional cases” in Sweden. The U.K. is currently reviewing the use of puberty blockers in NHS gender clinics.
All of this is justified by the contention that the science on puberty blockers is uncertain, due to a lack of good evidence, or conversely because the evidence points to serious harms.
If we cut through all the controversy and media spin, what does the evidence actually say — or not say — about the use of puberty blockers as part of gender-affirming care for trans youth?
Blocking puberty
Puberty blockers – otherwise known as gonadotropin releasing hormone agonists (GnRHa) – prevent the release of hormones by the pituitary gland, which then blocks the creation and release of testosterone or oestrogen by the testes or ovaries, respectively.
In adolescents, this process initiates the onset of puberty, and so GnRHa effectively “block” this process — hence, “puberty blockers”.
GnRH agonists have been used to treat central precocious puberty — the early onset of puberty — in cisgender children since the 1960s. They’re described as “the gold-standard treatment of central precocious puberty (CPP) worldwide and have an enviable track record of safety and efficacy”.
As with all medications, puberty blockers can have some negative effects, primarily issues with bone health, such as a reduction in bone mineral density (BMD), and stunted growth. However, long-term studies show that these problems resolve once puberty blockers are stopped and pubertal development resumes.
Long-term studies have also shown that the use of GnRHa in cisgender children has no lasting impact on fertility for either boys or girls.
Far from being an “experimental treatment”, puberty blockers are highly effective at safely achieving the desired outcome — pubertal suppression.
So why all the alleged controversy surrounding the use of GnRH agonists when it comes to transgender youth?
Blocking transgender puberty
The use of GnRH agonists to suppress puberty in transgender youth first began in the 1990s, and is thus far from “experimental”.
They are a well-established aspect of gender-affirming care aimed at alleviating gender dysphoria, defined as a clinical level of distress as a result of incongruence between a person’s gender identity and their sex assigned at birth.
GnRH agonists are used only after an adolescent has started puberty, after assessment by a multidisciplinary team has confirmed a diagnosis of gender dysphoria, and then only when deemed safe and clinically necessary.
Their use is recommended by the Royal College of Psychiatrists, the Endocrine Society, the World Professional Association for Transgender Healthcare, and the American Academy of Pediatrics, among others.
Recent reviews of the evidence used to question the use of puberty blockers, such as the NICE (National Institute for Clinical Excellence) review carried out on behalf of the U.K. Cass Review, or the Florida State review, exclude many relevant studies and misconstrue the findings of others.
Their legitimacy and transparency has been seriously questioned by those inside and outside of the medical profession. A full discussion is beyond the scope of this article, but you can read detailed critiques of the NICE review here and the Florida State review here.
Though there is always a need for more research, it is entirely disingenuous to say that the use of puberty blockers to treat transgender youth isn’t based on adequate evidence, or that there is evidence of harm.
According to a research review from 2020, the positive effects of puberty suppression using GnRH agonists among transgender adolescents includes decreased suicidality, improved psychological functioning and improved social life.
Most importantly, puberty blockers prevent irreversible pubertal changes which are incongruent with the young person’s gender identity. Furthermore, research suggests that access to puberty blockers prior to gender-affirming hormone therapy can result in better outcomes compared to youth who did not receive puberty blockers.
One contention is that puberty blockers don’t reduce gender dysphoria — and this is true. However, this is to be expected: GnRH agonists only halt natal puberty, they aren’t “sex change” hormones, and so we wouldn’t expect the same effect that hormone therapy has in terms of reducing dysphoria.
Research shows that subsequent or concurrent use of GAH to initiate pubertal development in line with trans youths’ gender identity does improve gender dysphoria.
As one research paper put it, puberty blockers are neither the start or necessarily the end of gender-affirming care. Their use should be viewed within the wider context of individual transition tailored to an individual’s needs, which might include various different aspects of medical care, psychotherapy, and social transition.
What’s the harm?
Concerns have been raised about the impact that GnRH agonists and GAH might have on physical development, especially bone health and height.
What does the available evidence say?
One study in 2020 looked at bone health, specifically bone mineral density (BMD) among transgender youth who used GnRHa for two years and then combined GnRHa and GAH for three years. For transgender boys (assigned female at birth — AFAB), bone mineral density returned to normal levels after three years.
For transgender girls (assigned male at birth — AMAB), bone density also improved after three years of combined treatment, though levels were less than optimal; however, bone mineral density was already lower pre-treatment, indicating that other factors other than use of puberty blockers were responsible.
Interestingly, multiple studies have found that markers for bone health like BMD (and other markers, like lean body mass and BMI) are lower at baseline before GnRH and GAH treatment for both trans girls and trans women.
Lower calcium levels, lack of vitamin D, and lower levels of physical activity have been suggested as possible causes — things which could be the result of social factors, like a lack of social acceptance or engagement (due to stigma or low self-esteem), or an underlying biological or genetic cause in common with transgender identity development.
As for concerns around the impact of puberty blocker use on growth and height, research has found similar results to that of bone health: while growth is slowed during the period of puberty blocker use, height gain resumes once puberty blockers are stopped.
While there are slight reductions in height for trans girls (between 1–3cm) this is an expected outcome, given the switch to a female hormone profile, and might even be viewed as a positive, given the transition goals of many trans girls (to achieve a body type closer to that of an AFAB person).
Overall, concerns about negative physical impacts of puberty blocker use are unfounded, with the evidence indicating they are generally safe.
What about fertility?
The use of puberty blockers does not impact fertility, since their effects on pubertal development are entirely reversible; however, subsequent use of gender-affirming hormones can impact fertility.
It is important for young people using puberty blockers to receive fertility counselling and to be made aware of the impacts on future fertility. Crucially, it’s important that fertility preservation is offered, usually in the form of freezing either eggs or sperm for future use.
Recent research has shown that fertility preservation in this form is entirely viable for both trans boys and for the majority of trans girls who take puberty blockers before starting hormone therapy. More work on fertility preservation for trans girls is needed.
Unfortunately, the provision of fertility preservation is severely lacking in terms of both provision and access for both trans youth and adults, due to costs, issues with insurance, lack of understanding among healthcare professionals, and social stigma.
And, while considerations of fertility are obviously very important, the (potential) future parenthood of a trans youth shouldn’t be considered more important than their current health and wellbeing.
There are also other ways to become a parent, such as sperm and egg donation, and of course adoption.
Arguably, the over-emphasis on fertility concerns over the wellbeing of trans youth is informed by cis-heteronormativity — the idea that anything outside the accepted social norm of cisgender and heterosexual reproduction is “abnormal” and thus undesirable.
This is particularly the case for trans boys, with concerns around fertility often based in the notion of “compulsory motherhood”, the idea that the sole purpose of people assigned female at birth is to produce children.
Overall, fertility concerns are not a legitimate (nor insurmountable) reason to deny access to puberty blockers or GAH.
What do trans youth say?
One glaring omission from the debate around puberty blockers is the voice of trans youth themselves, as well as that of their families.
When we do listen to their voices, they tell a very different story compared to those opposed to the use of GnRH agonists and gender-affirming care who claim to be concerned for, and speak for, trans youth.
One study which spoke to trans youth and their parents revealed a culture where disbelief is the starting point in providing care to trans youth, and young people are constantly forced to “prove” their gender identity to healthcare professionals.
This often occurred repeatedly over long periods, and involved invasive and sometimes inappropriate questions which had little bearing on gender identity.
One family reported the requirement to confirm their child’s sexuality, despite this having no relationship with gender identity. Healthcare providers routinely conflated gender identity with gender expression, clothing, hobbies and other behaviours.
Young people who weren’t seen to conform to the stereotypes of their gender identity weren’t believed, and gender-affirming care was delayed or withheld.
There was a sense of having to comply with a process that was at times emotionally draining and even traumatic in order to receive care, or prevent care from being withdrawn.
These experiences completely contradict the often-repeated claim that young people are being rushed into gender-affirming care and puberty blockers, showing instead that the opposite is true.
Parents in another study discussed the positive impact of access to puberty blockers, and their concerns about that care being withdrawn, or what would have happened if gender-affirming care hadn’t been accessible because of laws banning such care.
Both trans youth and their parents have highlighted the benefit of delaying puberty and preventing irreversible physical changes. The young people experienced improvements to their wellbeing and sense of self, gained through treatment.
Puberty blockers: care or controversy?
Overall, the research and experiences of transgender youth clearly demonstrate that the use of puberty blockers is safe, effective, and beneficial.
Many concerns around their use, when really examined, relate more to negative and pathologizing views of transgender people, rooted in ignorance of trans people’s experiences and needs — not concern for transgender youth.
One study accurately sums up the experiences and needs of transgender young people:
[T]ransgender young people know who they are, they know their gender, and they know the services they need. Certainly, there are aspects of their gender-related journeys that may be unknown, but that is true for any journey that involves focusing on the self. Parents of transgender young people, and the service providers who work with them, have an important role to play in listening to young people’s accounts of their needs.
We might add to that statement the need for politicians and those in the media to also listen to transgender young people, instead of talking over them and stoking fears and promoting false information.
When we cut through the toxic and ideological mainstream debate around the use of puberty blocker to treat transgender youth, we realise that there’s no controversy to be found.
The real controversy is that the adults in the room — those in government, and even those in leading medical bodies such as the NHS — are being swayed by emotional, anti-scientific arguments from anti-trans groups, their own transphobic bias, or just plain ignorance.
The results are devastating for trans young people: their care is being denied or withdrawn, and their futures put in jeopardy. That is a tragedy that those with the power to act should truly be ashamed of.