Puberty blockers
Puberty blockers
Puberty is the process of physical development that turns children into adults capable of reproduction. Puberty blockers are powerful drugs – developed and tested for other uses – that disrupt this process by stopping the ovaries producing oestrogen or the testicles producing testosterone. Their risks are not yet known, and their benefits are not clear: there are increasing concerns over their side effects, and disagreement over whether children can consent to their use.
Puberty blockers disrupt the normal process whereby puberty starts by interfering with the normal release of two chemicals – luteinising hormone (LH) and follicle stimulating hormone (FSH) – from the pituitary gland (a part of the brain). It is the release of these two hormones that kickstarts puberty, sending the signal to a girl’s ovaries or a boy’s testicles to start producing sex hormones (oestrogen for girls, testosterone for boys).
The way these drugs work is a little complicated. Normally, the brain releases another hormone, gonadotropin-releasing hormone (GnRH), in short pulses, and it is these pulses that stimulate the pituitary gland to make LH and FSH. Puberty blockers deliver this same GnRH signal, but they do so continuously rather than intermittently. This overwhelms the pituitary gland so that it no longer responds by producing LH and FSH, and the ovaries or testicles no longer get the signal to ramp up production of oestrogen or testosterone.
The technical name for puberty blockers is gonadotropin-releasing hormone agonists or analogues (GnRHa). Drug manufacturers have run clinical trials on them for the treatment of adults with certain cancers. They have also been tested and approved for delaying puberty by a year or two when it starts abnormally early (before age eight for a girl, or nine for a boy), to bring it closer to the normal timing.
Their use by gender clinics to stop normal puberty, however, has never been subjected to clinical trials. There are no robust studies, either published or under way, of their use as a treatment for gender dysphoria. What is known from data released by some gender clinics is that nearly every child who takes puberty blockers for gender issues will go on to take cross-sex hormones.
Risks and benefits of puberty blockers
Although puberty blockers are often described as merely a “pause button” for children with gender dysphoria – extra time to grow out of the condition before the irreversible changes of puberty – there is growing evidence that instead they permanently alter the child’s future path. In the UK, it appears that 98% of children started on GnRHa in early puberty go on to take cross-sex hormones; before puberty blockers started to be used by gender doctors, every study found that most such children recovered from gender dysphoria without any drugs.
Every medical treatment will have different risks and benefits. These depend not only on the treatment itself, but on the person taking the drug, and the condition for which they are taking it. GnNHa drugs have been judged sufficiently safe and sufficiently useful to be considered as a treatment for certain adult cancers and for precocious puberty. But this does not mean they are either safe or beneficial when used to block normal puberty as a prelude to cross-sex hormones.
Their use in gender medicine presents some risks unlike those related to any other medical treatment. One is that puberty normally occurs during adolescence, meaning that the body, brain and social role all mature together. Delaying puberty means these developmental strands are no longer synchronised. The child remains physically, and in some respects mentally and emotionally, immature while their peers are growing up and the world around them is moving on. People’s lives do not have a pause button. Developmental processes and experiences that are foregone cannot simply be caught up later on.
Another is harm to the child’s future sex life and fertility. It is during puberty that ovaries and testes start to produce mature eggs and sperm. A child whose ovaries or testes are kept in a childhood state, especially one who goes straight to cross-sex hormones (as most puberty-blocked children do), is likely to be permanently sterile. They may also be unable to experience sexual pleasure when they have grown up.
A third is skeletal problems in adulthood. Puberty is a critical time for strengthening bones. Disrupting or delaying it is likely to result in lower peak bone density, and to greatly increase the risk of osteoporosis (brittle bones) and fractures later on.
And finally, there are worries about the impact of puberty blockers on brain development, which continues into the third decade of life. One study in sheep found that blocking puberty worsened memory and cognition. GnRHa may harm learning, memory, mood, and psychosexual maturation. Among the known side-effects of these drugs, when used for their licensed indications, are depression and suicidal thoughts.
Consent to the use of puberty blockers
Some clinicians think it is impossible for a child to consent to such drugs, in part because their long-term effects are not well understood and in part because no child can possibly fully comprehend what it would mean to spend the rest of their life unable to have children or enjoy sexual pleasure. There have been legal cases concerning such matters, notably a judicial review brought by Keira Bell against the Tavistock and Portman Trust in the UK in 2020. The initial findings – that valid consent would be impossible to get from a child under 13, and very hard to get from a child under 16 – were overturned on appeal in 2021. But the evidence given revealed serious questions about the lack of data on long-term outcomes in gender medicine, and safeguarding and ethical issues with puberty blockers. Such problems may lead patients to sue clinicians in the future.