puberty blocker

puberty blocker, medication that temporarily stops the actions of hormones responsible for physical changes that occur during puberty, such as breast development in females and growth of the testes and deepening of the voice in males. Puberty blockers are often used in medical settings for children and adolescents who are experiencing precocious puberty or who do not want these changes to occur, as in gender dysphoria. In transgender or gender-diverse adolescents, puberty blockers potentially provide time for individuals to explore their gender identity before making permanent decisions about transitioning.

Types and mechanisms of action

The most commonly used puberty blockers are gonadotropin-releasing hormone (GnRH) agonists, examples of which include goserelin, leuprorelin, and triptorelin. These drugs work by interfering with GnRH, which is secreted by the hypothalamus in the brain and stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH then stimulate the gonads (the ovaries in females and testes in males) to produce estrogen and testosterone, the hormones responsible for the development of secondary sexual characteristics and the progression of puberty. The continuous administration of GnRH agonists, over weeks or months through injections or implants, leads to the downregulation of GnRH receptors in the pituitary, rendering it less responsive to the hormone. As a result, LH and FSH production decreases significantly, leading to reductions in estrogen and testosterone production and thus suppressing the physical changes of puberty. The effects of puberty blockers typically are reversible—when the medication is stopped, within about three to six months the pituitary gland regains sensitivity to GnRH, and estrogen and testosterone production resumes.

Other types of drugs that may be used or that are under investigation as puberty blockers include antiandrogens, such as spironolactone and cyproterone acetate; antiestrogens, such as aromatase inhibitors; and the progestin medroxyprogesterone acetate (MPA). Spironolactone and cyproterone acetate may be used to suppress puberty in transgender girls (individuals assigned male at birth). Aromatase inhibitors, which prevent the formation of estrogen from androgen hormones, are sometimes used to treat boys or girls affected by gonadotropin-independent precocious puberty. MPA is a synthetic progesterone that acts by suppressing gonadotropin and sex hormone production, thereby suppressing puberty.

Side effects

Puberty blockers can cause various side effects, including fatigue, headaches, hot flashes, and mood changes. Long-term use may be associated with more serious or permanent side effects, such as alterations in overall growth patterns, with impacts on final height and body composition, and decreased bone density, which requires monitoring and additional treatment, often involving supplementation with calcium and vitamin D. Prolonged use may affect fertility in adulthood, particularly for individuals who also undergo cross-sex hormone therapy for gender transition. In addition, research in animals suggests that suppressing puberty can impact brain structure and cognitive function, raising concerns about similar effects on the human adolescent brain and cognitive development. Adolescents who are treated with puberty blockers are further susceptible to emotional and social challenges, especially if physical puberty changes are delayed for gender-related reasons.

Regulatory and social issues

The use of puberty blockers in adolescents, especially transgender youth, raises significant social and regulatory concerns. These concerns generally reflect broader debates about gender identity, the role of government in health care, and the medical management of minors. Potential risks and unknowns about puberty blocker medications, for example, have prompted health regulators in some countries to call for more research and to restrict the use of such treatments. Hence, medical guidelines vary—in some places, puberty blockers are considered an essential tool for providing transgender youth with the opportunity to delay irreversible physical changes. In other places, they are more heavily regulated, and medical professionals may face legal risks for prescribing them. In the United Kingdom, for example, puberty blockers were banned in 2024, owing to a lack of evidence on benefits and harms of treatment.

There also is ongoing social debate about the appropriateness of puberty blockers for minors and about the impact on increased acceptance of gender diversity, which may lead some young persons to transition prematurely or without fully exploring their gender identity. Moreover, peer influence and social media portrayals of gender diverse individuals could lead adolescents to assume that transition is the only path forward. Some individuals who delay puberty for gender-related reasons may also face heightened mental health risks due to societal rejection and discrimination. However, some studies suggest that gender-diverse teens who use puberty blockers benefit mentally and socially.