Puberty blockers, also called puberty inhibitors, puberty suppressants, puberty suppressors, or hormone suppressors, are a group of medications used to inhibit puberty. They were originally used to treat children with precocious puberty or other such early onset of puberty. Puberty blockers are commonly used for the transgender community. In this community, puberty blockers are used to provide transgender youth with time to further explore their identity, while halting the development of their predisposed sex characteristics caused by the onset of puberty.
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 each 3, 4 or 6 months (Lupron Depot-3 month, Lupron Depot-PED-3 month, Lupron Depot-4 month, Lupron Depot-6 Month). Depot Lupron can cost from $700 to $1,500 a month depending on the country where it is practiced.
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 patient must be careful after the operation to keep the cut clean, dry, and to not move the bandage and the surgical strips or stitches used to close the incision on the skin. The drug is then gradually released in the body during 12 months and it has to be replaced by another one later to continue the treatment. The total cost of histrelin treatment with the surgery 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.
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 for children and adolescents and the halting of female features of breast development and menstruation.
The primary risks of pubertal suppression in gender dysphoric youth treated with GnRH agonists include adverse effects on bone mineralization, compromised fertility, and unknown effects on brain development. A 2015 study published by the Principles of Transgender Medicine and Practice, observed the executive functioning in 20 youth transgender treated with puberty blockers compared to untreated trans youth. They found that there was no difference in performance.
Transgender youth are a specific target population of puberty blockers. Gonadotropin-releasing hormone (GnRH) agonists (e.g., leuprorelin, histrelin) to halt puberty, can be used for transgender youth before the development of natal secondary sex characteristics.
Puberty blockers serve the transgender community by giving future trans men and trans women more time to solidify their gender identity, without developing secondary sex characteristics. If a child later decides not to transition to another gender, the effects of puberty blockers can be reversed by stopping the medication.  Another function of puberty blockers is that it gives the future transgender individual a smoother transition into their desired gender identity as an adult.
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To prevent the consequences of going through a puberty that doesn’t match a transgender child’s identity, healthcare providers may use fully reversible medications that put puberty on hold.