What Parents Need To Know About Hormone Blockers

Stephanie P.*, a mother of three in Pennsylvania, began noticing hormonal changes in her daughter when she was just 18 months old.

"She was showing signs of puberty," she says. "She smelled like a teenager. She had body odor."

Her pediatrician wasn't initially concerned, but at age 3, the child suddenly grew multiple inches over a few weeks and developed pubic hair. The family was sent to an endocrinologist who diagnosed the toddler with precocious puberty, which is puberty that begins earlier than average. This condition affects less than 1% of the U.S. population but might be becoming more common.

There are three types of precocious puberty: central, peripheral, and incomplete, according to the Cleveland Clinic. Each warrants a different treatment approach to slow or halt puberty progression depending on its root cause. Interventions include treatment for an underlying illness or endocrine condition, environmental and dietary changes, and/or hormone-blocking medication, which is FDA-approved for kids who start puberty early.

Hormone blockers are also used in gender-affirming health care. Anti-trans legislators have introduced the idea that hormone blockers are harmful, but a February statement released by the Endocrine Society, a network of physicians dedicated to the study of hormone science, condemns attempts to revoke blockers from trans youth.

For Stephanie's daughter, doctors eventually recommended that she go on hormone blockers, and in 2019, she chose an implant that remained in her arm for two years and was removed when she turned 13. The family's positive experience with puberty blockers helped Stephanie feel comfortable and confident when her younger child, who is now 11, considered similar options for gender-affirming care. As a former librarian, Stephanie also read scholarly research in peer-reviewed journals and trusted her family's doctors to guide them.

Parents who are concerned about hormone blockers should be aware of misinformation about the medication and become more familiar with its history, uses, and safety.

What Are Hormone Blockers?

Hormone blockers, also called puberty blockers and puberty inhibitors when prescribed to children, treat a variety of health concerns, including cancers, across diverse populations. Puberty blockers often refer to a class of medications called gonadotropin-releasing hormone (GnRH) agonists, which suppress the body's production of estrogen and testosterone by temporarily interrupting the release of GnRH by the hypothalamus in the brain. When a blocker is not in place, GnRH travels to the pituitary gland (located at the base of the brain) and stimulates it to make and release follicle-stimulating hormone and luteinizing hormone, which regulate processes in the reproductive system.

Hormone blockers are either given as an implant, which typically needs to be replaced every year (like Stephanie's daughter chose), or as a shot every one, three, or six months. Children are usually prescribed blockers for short-term use once the early stages of puberty have started—not as a preventative measure before that process begins. For both trans kids and those with precocious puberty, the goal is to temporarily prevent the unwanted progression of puberty.

Stephanie Roberts, M.D., a pediatric endocrinologist at Boston Children's Hospital, calls the effects of hormone-blocking medication a "transient pause in puberty." GnRH agonists prevent the development of breasts, menstruation, mature body hair, facial hair, and voice changes. Other blockers can be used to target a patient's specific needs. For instance, anti-androgens specifically reduce the impact of testosterone and progesterone can pause menstruation.

Children with precocious puberty often have an advanced bone maturation rate causing them to encounter growth spurts earlier than others. Without medical intervention, their growth plates fuse at a younger age, and can result in shorter stature. Blockers also allow them to reach a more typical height. Some trans youth with height-related body dysmorphia might also benefit from this effect, but more research is needed.

Dr. Roberts explains that puberty-blocking medications do not permanently impact puberty. Treatment durations vary, but puberty progression generally resumes within six to 18 months after users stop the medication.

Hormone Blockers Safety

GnRH agonists became the standard intervention for central precocious puberty in 1981, but the treatment wasn't approved by the FDA until 1993. Today, these prescriptions are considered "off-label" when prescribed for gender affirmation because the approach is not yet FDA-approved, but it has been a standard of care for gender dysphoria since the mid '90s.

"Off-label" does not mean the use isn't suitable. A study exploring off-label usage in pediatrics stated that off-label prescribing, which is both legal and common, is a best practice when clinical experience and evidence support the approach. The study found the most frequently ordered off-label prescriptions for kids were antihistamines for respiratory infections and antidepressants for ADHD.

Experts also point out that hormone-blocking medications haven't been found to be dangerous. "We have a longitudinal experience with these medications for several decades and a large clinical experience. The sheer number of patients we've treated in our program let us see for ourselves that it's safe and effective," says Dr. Roberts. "The benefits far outweigh any potential risks."

Children who take the medications are monitored for efficacy and screened for side effects and adverse outcomes. They are generally mild and temporary but can include rare occurrences of hypertension, vision problems, and allergic reactions.

"Bone density is one of the concerns," says Dr. Roberts, explaining that parents often ask about this risk. She explains that patients could see a reduction in bone density while they use blockers, but those who used blockers for precocious puberty during childhood have been found to have the same bone density as those who didn't in adulthood.

Caregivers sometimes also raise questions about possible impacts on fertility. Studies show that children with precocious puberty who use blockers do not have impaired fertility after use. But fertility counseling could be incorporated into conversations about these therapies. It's a topic, though, that hasn't been well-researched in trans users.

"People in the medical community have not studied trans people in an affirming and non-pathologizing way for very long—and it takes quite a bit of time to study things like fertility, as these outcomes would happen decades after puberty blockers," explains Quinn Jackson, M.D., a family practitioner in Kansas City, Kansas, who has a special interest in caring for gender-nonconforming patients. "This is one of those areas where we don't have a ton of data to guide us."

Dr. Jackson underlines that families should be aware of all potential risks, adding, "Families can compare the unknown risks of fertility with the very real and known risks of not treating trans kids and forcing them into a puberty experience they don't want."

Hormone Blockers and Mental Health

"A common misconception is to do 'watchful waiting' or 'observation' of a child where puberty-blocking medications or gender-affirming hormones are really indicated. But if the child does not receive those puberty-blocking medications, that's not a neutral decision," says Dr. Roberts. "By not intervening when it is indicated to do so, that has the clear potential to do harm."

Many trans and gender nonconforming kids suffer psychosocially as puberty begins. A trans boy who experiences menstruation, for example, might feel alienated from peers or disconnected from his body and likely lacks access to hygiene products in many settings. When trans kids who want to take blockers have access to the medication, they have lower risks for suicidal ideation throughout their lifetime, improved psychological effects, and better social lives.

Kids who go through precocious puberty can also be negatively impacted without treatment. Research shows a correlation between early puberty and adverse psychological, social, and behavioral outcomes, including negative self-image, strained peer relationships, greater likelihood of substance use, and higher rates of depression and anxiety.

A child's psychosocial life stage "may not allow them to adapt to the continuing progression of puberty," Dr. Roberts explains. For example, a young child who experiences their menstruation earlier than expected might feel stressed and confused by mood swings, physical sensations, or hygiene responsibilities they aren't yet prepared to handle. They might also lack access to hygiene products, mental health care, and other supports older students receive in school.

Supporting Kids Who Need Hormone Blockers

Legislation is popping up across the country in an effort to criminalize trans-affirming health care for youth. Although it's unlikely that kids with precocious puberty will be impacted by anti-trans legislation, insurance issues can and will continue to impact all children. Trans youth are at increased risk for insurance mishaps, as insurance often fails to cover off-label prescriptions.

"The history of pathologizing trans identity forces trans people to interact with the medical community and receive a medical diagnosis in order to access the things that allow them to live the way they want to live," says Dr. Jackson. "It means that we have to continue participating in the medicalization of the trans experience."

Dr. Jackson adds, "As a medical doctor, I have a hard time envisioning it a different way. But as a trans person, I really wish it could exist in a different way." It's important, Dr. Jackson says, that caregivers work with medical professionals to destigmatize the use of blockers by avoiding pathologizing language. The reality is blockers could simply offer a helpful pause for kids experiencing unwanted puberty changes.

Both cisgender and transgender children might take drastic measures to suppress the physical appearance of puberty changes if medical interventions aren't accessible. Unhealthy coping habits, like disordered eating, could also develop. Trans youth who lose access to therapies if laws begin to shift might feel a loss of control over their lives, be more desperate to suppress their body's changes, and need trans-competent mental health care.

Emotional support from caregivers is crucial. "An adult's reaction is the model for the kid's response," says Rachel Sacharoff, LMFT, who specializes in supporting patients with chronic health concerns and also sees trans clients. She underlines that parents have a responsibility to empower their children with language that normalizes their experiences, makes space for their feelings and challenges, affirms their treatment plans, and helps them feel loved and safe.

Sacharoff suggests parents can also talk to appropriate providers. "They've dealt with this before and can give parents all the information they need to understand what's happening with their kid and how to better support their kid with whatever's going on for them."

*Last names have been withheld for privacy.