
In January, papers were lodged at the British High Court against the Tavistock and Portman NHS Trust, which runs the UK鈥檚 only gender identity development service (GIDS).
The claimants against the Trust want to establish a legal minimum age of 18 for puberty blocking hormone therapy for young people diagnosed with gender dysphoria, with their lawyers arguing that it is illegal to prescribe the drugs to anyone younger as they cannot give informed consent to the treatment.
The case has been brought about by the parent of a 15-year-old on the GIDS waiting list known as Mrs A, who does not believe children can understand the ramifications of taking puberty blockers. Alongside her is a 23-year-old woman named Keira Bell, who transitioned to male as a teenager but has since detransitioned and believes she should have been challenged more by GIDS during the process.
So-called puberty blockers, known formally as gonadotropin-releasing hormone (GnRH) antagonists, are medications that cause the body to stop producing sex hormones. They are delivered either as leuprorelin injections, which are administered by a healthcare worker every three months, or via a histrelin implant, which needs to be replaced annually.
The GnRH antagonists bind to receptors in the pituitary gland, blocking the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary. This leads to suppression of testosterone production in the testes or the suppression of estradiol and progesterone production from the ovaries, depending on the anatomy of the individual taking them.
For young trans people, taking these drugs will prevent things like breast tissue development and periods, or the growth of facial hair and a deepening voice. The effects of drugs are completely reversible, and if a person stops taking them their body will resume sex hormone production as it had done before they started.

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By GlobalDataAs well as being used to suppress puberty in gender-questioning youth, they鈥檙e used from the age of six onwards for the management of听precocious puberty, when a child鈥檚 body enters adolescence too early. GnRH antagonists are also used to treat prostate cancer, as part of IVF fertility treatment and for the management of uterine disorders such as endometriosis or fibroids. They鈥檙e even being investigated as a treatment for women with hormone-sensitive breast cancer, as a treatment for benign prostatic hyperplasia and as a potential contraceptive.
Why might a young person want puberty blockers?
Gender dysphoria – the sense of unease arising from one鈥檚 physical sex characteristics not aligning with one鈥檚 gender identity – can be just as unpleasant for young people as it is for adults.
Pacific University Oregon co-director of child psychology Dr Laura Edwards-Leeper says: 鈥淭he impact of going through the wrong puberty for a child who is transgender can be devastating, as their body feels as if it is out of their control and changing in a way that is incongruent with their gender identity. This can lead to a host of psychological problems, most often depression, anxiety, low self-esteem, self-harming behaviours and suicidality.鈥
When puberty blockers are used to delay or prevent these changes, they鈥檙e essentially used to buy time. They鈥檙e primarily intended to give young gender-questioning people a few years to weigh up their options before going through any permanent bodily changes, whether those are through hormone replacement therapy (HRT) to induce a puberty which corresponds with their gender identity, or discontinuing the blockers altogether and allowing puberty to proceed as it would have done without any intervention.
鈥淚t is important that the young person fully understands that they can change course at any time and that no one will be disappointed in them or feel that they made 鈥榓 mistake鈥 or 鈥榙idn’t know who they were鈥 when they made the decision to start blockers,鈥 says Edwards-Leeper.
鈥淧arents, other family members, providers, friends and peers and school staff need to understand this as well, so that the young person does not feel boxed in. Just as we do not want trans youth to feel pressured into being cis, we don’t want gender diverse youth to feel pressured into being trans if they ultimately feel that this does not fit for them.鈥
How are puberty blockers prescribed in the UK?
While many people who oppose the use of blockers听, most patients actually face a lengthy waiting period. In November 2019, doctors in the UK GIDS were beginning initial consultations with patients who had been referred in September 2017, more than two years beforehand. Even then, puberty blockers won鈥檛 be prescribed immediately.
Val, a 19-year-old transfeminine student, came out at 13 and had her first appointment with the UK GIDS soon after, but didn鈥檛 receive puberty blockers until she was 17.
鈥淚 think the thing I find really distasteful is all the things in the media about how they鈥檙e fast-tracking trans people,鈥 she says. 鈥淚鈥檓 like, 鈥榯hey鈥檙e not!鈥. During that process you have to put your life on hold. It鈥檚 like an axe that鈥檚 hanging above your head all the time and you don鈥檛 know when it鈥檚 going to drop and it鈥檚 terrifying. Puberty blockers allow trans teenagers to finally get back to living their lives. They just give you peace of mind.鈥
More than 5,000 young people are currently on the GIDS waiting list, and according to a听听only 267 people under the age of 15 started using blockers between 2012 and 2018. While things differ internationally, the UK GIDS will not prescribe HRT to a young trans person unless they have spent 12 months on blockers and are at least 16 years of age.
While it鈥檚 important to acknowledge that detransition does happen, what鈥檚 vital is that cases like Keira Bell鈥檚 are rare. Most recent studies estimate the overall detransition rate for trans people to be听.
鈥淔ar more trans kids live with lifelong impacts of decisions that we seem to be making based on one cis kid who gets referred accidentally,鈥 says Val.
Do puberty blockers have any serious side effects?
Puberty blockers are safe as far as can be determined from the experience of non-transgender children who take them or women undergoing fertility treatments who take them,鈥 says Mount Sinai Center for Transgender Medicine and Surgery executive director Dr Joshua Safer.
Like all medications, the blockers are still known to have some side effects, including weight gain, hot flashes, headaches and swelling at the site of injection. There also may be more long-term effects on bone density, which is part of the reason the drugs aren鈥檛 supposed to be prescribed for too long.
Safer explains: 鈥淭he primary concern is that bones might be at greater risk of osteoporosis because bones depend on sex hormones for maintenance. That need is part of the reason that women typically are at risk for osteoporosis earlier than men, as women go through menopause and suffer a loss of sex hormones while men don鈥檛 typically have a similar significant hormone change. But the risk is hard to see when only taking puberty blockers for a year or two.鈥
It鈥檚 also worth noting that there is a relationship between puberty blockers and fertility. Sperm production typically begins between 13 to 14, and egg maturation between 12 to 13, and the vast majority of trans children will begin puberty blocker treatment after these processes have already occurred.
In these cases, sperm or eggs can be frozen before treatment and may be used to conceive a child in later life. If a young person decides not to transition after all and ceases puberty blocker treatment, the Endocrine Society advises that no studies have reported long-term, adverse effects on ovarian function. For people with testicles, sperm numbers can fall below the normal range in some cases.
Things are slightly different for the small number of trans children who may undergo puberty blocker therapy before sperm or egg maturation occurs and then immediately begin HRT. As they will be unable to have a sperm or egg sample frozen, they don鈥檛 have the same fertility preservation options that children who start taking blockers when they鈥檙e slightly older would have.
鈥淭he concern is hormone treatment would have to be stopped in order to restore fertility later were it desired 鈥 perhaps for many months,鈥 says Safer. 鈥淭he concern is part of the reason for puberty blockers 鈥 to allow time to have the conversations that will allow reasoned choices being made regarding hormone therapy.鈥
Of course, any medical decision which could have an impact on fertility is one that听requires a lot of time and care to consider. However, many trans people find the way the impact on fertility is used to argue about the ethics of trans healthcare inherently problematic.
Val says: 鈥淚t鈥檚 something that gets brought up and is very much rooted in the idea that if you are infertile that is somehow lesser and you are lesser of a person, which is not at all correct.鈥
Gillick competence and the future of trans healthcare
In England and Wales, the term 鈥楪illick competence鈥 is used in medical law to decide whether a child under the age of 16 is able to consent to their own medical treatment, without the need for parental permission or knowledge.
It means that the legal authority for parents to make medical decisions on behalf of their children is revoked when the child reaches sufficient maturity to make their own decisions. There is no hard-and-fast age at which a child can be considered 鈥楪illick competent鈥, and it is something decided on a case-by-case basis.
The claimants in the ongoing UK court case against Tavistock and Portman believe that Gillick competence should not apply when it comes to gender reassignment,听: 鈥淲e say it is a leap too far to think that Gillick as a judgment could apply to this type of scenario, where a young person is being offered a treatment with lifelong consequences when they are at a stage of emotional and mental vulnerability. It simply doesn鈥檛 compute, and therefore whatever medical professionals say is consent is not valid in law.鈥
Yet, a study published this year in the journal听Pediatrics听听access to puberty blockers can be life-saving, reducing the chances of suicide among young trans people, who are at much greater risk of this than the general population. It鈥檚 hard to see how revoking Gillick competence for a reversible, life-saving treatment stands up from a medical ethics standpoint.
While many parents and carers of transgender children understandably worry about what the future holds for their kids in a world that听isn鈥檛 especially kind to gender nonconforming people, that worry should never be allowed to become so overwhelming that they seek to strip away essential health services out of fear.
A representative of UK trans children鈥檚 charity Mermaids says: 鈥淭he important thing to remember is that all journeys and identities are valid, and by supporting your child, they will be able to continue along this journey knowing you love and care about them, whoever they are and whatever they choose to do.鈥