Puberty blocker

Puberty blockers, also called puberty inhibitors, are drugs used to postpone puberty in children. The most commonly used puberty blockers are gonadotropin-releasing hormone (GnRH) agonists, which inhibit the release of sex hormones, including testosterone and estrogen. In addition to their various other medical uses, puberty blockers are used off-label for transgender children to delay the development of unwanted sex characteristics, with the intent to provide transgender youth more time to explore their identity. The use of puberty blockers in transgender youth has been challenged on ethical and medical grounds, causing controversy over the morality and legality of their use. 
Medical uses.
Delaying or temporarily suspending puberty is a medical treatment for children whose puberty started abnormally early (precocious puberty). Puberty blockers are also commonly used for children with idiopathic short stature, for whom these drugs can be used to promote development of long bones and increase adult height. In adults, the same drugs are used to treat endometriosis and prostate cancer. Puberty blockers prevent the development of biological secondary sex characteristics. They slow the growth of sexual organs and production of hormones. Other effects include the suppression of male features of facial hair, deep voices, and Adam's apples, and the halting of female features of breast development and menstruation.
Puberty blockers are sometimes prescribed off label (with the FDA) to young transgender people, to temporarily halt the development of secondary sex characteristics. Puberty blockers allow patients more time to solidify their gender identity, without developing secondary sex characteristics. If a child later decides not to transition to another gender the medication can be stopped, allowing puberty to proceed, as the effects are fully reversible. Puberty blockers give transgender youth a smoother transition into their desired gender identity as an adult.
While few studies have examined the effects of puberty blockers for gender non-conforming or transgender adolescents, the studies that have been conducted indicate that these treatments are reasonably safe, and can improve psychological well-being in these individuals. A 2020 UK Department of Health commissioned review found that the quality of evidence was of very low certainty for puberty blocker outcomes regarding mental health, quality of life and impact on gender dysphoria.
Adverse effects on bone mineralization and compromised fertility are potential risks of pubertal suppression in gender dysphoric youth treated with GnRH agonists. Additionally, genital tissue in transgender women may not be optimal for potential vaginoplasty later in life due to underdevelopment of the penis.
Research on the long term effects on brain development is limited.
Administration.
The medication that is used in order to stop puberty comes in two forms: injections or an implant.
The injections are leuprorelin made intramuscularly by a health professional. The patient may need it monthly (Lupron Depot, Lupron Depot-PED) or every 3, 4 or 6 months (Lupron Depot-3 month, Lupron Depot-PED-3 month, Lupron Depot-4 month, Lupron Depot-6 month).
The implant is a small tube containing histrelin. The implant needs to be replaced every year and is implanted subcutaneously in the upper arm. The doctor makes a small cut in the anesthetized skin of the patient and then inserts the implant. The drug is then gradually released in the body over 12 months and the implant has to be replaced to continue the treatment. The total cost of histrelin treatment with the surgery in the USA is $15,000.
The combination of bicalutamide (an antiandrogen) and anastrozole (an aromatase inhibitor) can be used to suppress male puberty as an alternative to GnRH analogues, or in the case of gonadotropin-independent precocious puberty, such as in familial male-limited precocious puberty (also known as testotoxicosis) in boys, where GnRH analogues are ineffective.
Legal and political challenges.
Legal proceedings in the United Kingdom have sought to prohibit the use of puberty blockers for transgender children. Legislation proposed in South Dakota sought to restrict access to puberty blockers, and other treatments, for transgender children under sixteen. There is criticism regarding issues of informed consent and limited research support for the use of puberty blockers on transgender children. The Endocrine Association Guidelines call for more rigorous safety and effectiveness evaluations and careful assessment of "the effects of prolonged delay of puberty in adolescents on bone health, gonadal function, and the brain (including effects on cognitive, emotional, social, and sexual development)."
Some opponents of the use of puberty blockers argue that minors are not able to give proper consent. Some advocates for the use of puberty blockers consider the psychological and developmental benefits of puberty blockers compelling enough to overlook the issue of informed consent in many cases. Consent is often achieved after extensive analysis and counseling.
Bioethicist Maura Priest contends that, even in the absence of parental permission, the use of puberty blockers could mitigate any adverse effects on familial relationships within the home of a transgender child. She posits that there are benefits to having access to puberty blockers, while psychological costs are often associated with untreated gender dysphoria in children. Bioethicist Ashley Florence adds that counseling and educating the parents of transgender youth could also be beneficial to familial relationships.
Michael Biggs has said that studies on the effects of puberty blockers on transgender children lack transparency or validity. Physician Carl Heneghan has called the use of puberty blockers to treat transgender children an "unregulated live experiment on children." Opponents express concern over validation of a child's gender dysphoria; however, research has shown that treatment with puberty blockers prevents harmful behavior and does not increase gender dysphoria. Research has suggested that the use of puberty blockers decreases the risk of depression and contributes to the mitigation of behavioral issues. Opponents to the use of puberty blockers have argued that puberty blockers encourage children to go through with cross-sex hormones and gender reassignment surgery. A study regarding the long term effects of puberty blockers found that, upon later assessment, subjects did not regret transitioning and were less likely to experience depression in early adulthood.
Opponents of the use of puberty blockers in adolescents argue that gender identity is still fluctuating at this age and blockers might interfere with gender identity formation and development of a free sexuality.  Also, in around 70–90% of children with GD, it does not persist after puberty. Almost all (98%) children who took puberty blockers in a significant recent study by the main UK child/adolescent gender clinic continued on to hormones. Similarly, most reviews noting psychological benefits refer to the classic Dutch study which had very stringent requirements for medical treatment,  later studies have had mixed results.