What are Puberty Blockers?

Puberty blockers, also called GnRH agonists (Gonadotropin-Releasing Hormone agonists), are medications that temporarily pause puberty in transgender adolescents experiencing gender dysphoria. They suppress the production of sex hormones (testosterone or estrogen), preventing the development of unwanted secondary sexual characteristics.

Who are they for?

Puberty blockers are used in adolescents who:

• Have a well-documented, persistent gender dysphoria
• Are experiencing distress from unwanted pubertal changes
• Have started puberty (Tanner Stage 2 or beyond)
• Have undergone comprehensive mental health evaluation
• Have parental/guardian consent and support (in most jurisdictions)

Common GnRH Agonists Used:

• Leuprolide (Lupron Depot): IM injection every 1-3 months
• Triptorelin (Trelstar): IM injection every 1-6 months
• Goserelin (Zoladex): Subcutaneous implant every 1-3 months
• Histrelin (Supprelin LA): Subcutaneous implant (yearly)

How do they work?

GnRH agonists initially cause a surge in LH/FSH, followed by downregulation and suppression of these hormones. This stops the gonads (testes or ovaries) from producing testosterone or estrogen, effectively pausing puberty.

What changes occur with puberty blockers?

In Transgender Girls (Assigned Male at Birth):

• Prevents deepening of voice
• Prevents growth of facial and body hair
• Prevents development of Adam's apple
• Prevents male pattern muscle/bone development
• May reduce height (prevents male growth spurt)

In Transgender Boys (Assigned Female at Birth):

• Prevents breast development
• Prevents menstruation
• Prevents widening of hips
• Prevents female fat distribution

Benefits:

• Reduces Gender Dysphoria: Prevents development of distressing secondary sexual characteristics
• Provides Time: Allows adolescents more time to explore their gender identity before irreversible changes occur
• Improves Mental Health: Reduces anxiety, depression, suicidality in many patients
• Better Outcomes if Transition Pursued: Fewer unwanted physical features to reverse (e.g., no need for voice surgery, easier to "pass" as affirmed gender)
• Reversible: If stopped, puberty resumes

Potential Risks and Side Effects:

• Bone Density: Temporary reduction in bone density; reversible when sex hormones resumed
• Height: May result in shorter stature (if started early)
• Fertility: Long-term effects on fertility are uncertain, especially if followed immediately by gender-affirming hormones
• Sexual Function: Delayed sexual development may affect future sexual function (more research needed)
• Hot Flashes, Mood Changes: From low sex hormones
• Weight Gain
• Injection Site Reactions

Monitoring:

• Labs (every 3-6 months): LH, FSH, testosterone/estradiol (should be suppressed to prepubertal levels)
• Bone Density (DEXA scan): Baseline and periodically (ensure adequate calcium/Vitamin D supplementation)
• Tanner Staging: Assess pubertal development (should remain stable)
• Mental Health: Ongoing support and monitoring
• Height, Weight, BMI

What happens next?

Option 1: Continue to Gender-Affirming Hormones (age 14-16+):

• Transition to estrogen (transgender girls) or testosterone (transgender boys)
• Induces desired pubertal changes
• Typically started around age 14-16 (varies by country/protocol)

Option 2: Discontinue Blockers:

• If adolescent decides not to pursue transition
• Endogenous puberty resumes within months
• No evidence of permanent harm from temporary suppression

Controversies and Considerations:

• Informed Consent: Adolescents may not fully understand long-term implications
• Fertility: Uncertainty about future fertility if blockers followed immediately by cross-sex hormones
• Bone Health: Long-term impact on peak bone mass unclear
• Desistance Rates: Some adolescents who identify as transgender in early puberty later identify as cisgender; blockers prevent exploration of natal puberty
• Ethical Debate: Balancing respect for adolescent autonomy, mental health benefits, and unknown long-term risks

Multidisciplinary Care:

Use of puberty blockers should be part of comprehensive care involving:

• Mental Health Professionals: For diagnosis, support, and ongoing therapy
• Pediatric Endocrinologists: For medical management and monitoring
• Primary Care Providers
• Family Support