The idea of becoming an adult is the coolest thing ever when you’re young. Growing up is really exciting, but how do puberty blockers affect transgender youth?

You might have thought that life would begin once you reached a magical age. This age would usher you into adulthood. And for many kids, puberty is often regarded as the start of this journey.

Puberty is a monumental shift for every person. But what happens when the physical changes do not align with your gender identity? For young adolescents, this might take the form of a strong desire to avoid secondary sex traits such as facial hair or breast growth.

As a parent, you’re responsible for making the best medical and psychological decisions for your minor child. You’re aware of how tough puberty can be for transgender children, as well as the worry that comes with it. The adolescent years can be particularly difficult since your child’s body is continuously changing. 

In light of this, puberty blockers may be top on your research to-do list. Despite the abundance of information on the internet regarding puberty blockers, not all of it is useful (or helpful). We hope this article helps peel away the layers of misinformation surrounding puberty blockers for transgender youth and gender-diverse youth.

It’s important to note that it doesn’t matter what kind of transition a person chooses, where they are in the process, or how often they vacillate and change their minds — it doesn’t make their gender any more or less valid. A trans person is still a trans person, regardless of what medical interventions — if any — that person decides to undergo.

What Are Puberty Blockers?

You know that if your child wants to medically transition, puberty blockers are a necessary step in the process. You want to help your child, but you also have questions about the effects of puberty blockers on their development.

Puberty blockers function by preventing puberty-related changes in the body by suppressing testosterone and oestrogen production. This process will stop periods, breast growth, voice deepening, and facial hair.

Children who experience abnormally early puberty have been treated with puberty blockers for decades. During the 1990s, a transgender clinic in the Netherlands began using puberty blockers as a gender-affirming treatment.

How Do Puberty Blockers Help Transgender Youth?

They not only halt the unwanted physical changes, they also allow parents and healthcare providers the opportunity to discuss what options are available. Puberty blockers give the gift of time — by providing transgender youth with more time to consider their options.

At What Age Can Transgender Youth Start Puberty Blockers?

It depends — because some people aren’t aware of their gender identity until adolescence or later in life. Some children show signs of being transgender from an early age. The timing in which we discover our identity and how we do so is as unique as we are.

If a child hasn’t started puberty yet, there’s no puberty to block. During this time, it’s essential to provide your child with support for a social transition rather than a medical transition. Your child may opt to begin a social transition before puberty by changing their name, pronouns, clothing, and hairstyle.

However, once puberty begins, transgender children can begin their medical transition with puberty blockers. Once this happens, the treatment prevents your child from experiencing puberty that isn’t in line with their gender identity.

Are Puberty Blockers Reversible for Transgender Youth

Yes, puberty blockers are fully reversible. When a person stops taking this medication, their body produces their natural hormones again, resulting in the development of breasts, facial hair, a deeper voice, and menstruation.

It’s also critical that a person understands that they have the ability to change their treatment at any time.

Puberty Blockers, Bone Scans, and Hormones for Transgender Youth

Bone growth is rapid during puberty. Bone density must increase in order for bone strength to maintain pace with growth. Hormones are vital for this.

We need hormones to keep our bones strong, which is evidenced in women who have gone through menopause. As their hormone levels reduce, so does the density of their bones, putting them at greater risk of fracture.

Teenagers on puberty blockers, or those who experience a naturally late puberty, may miss out on essential bone growth. It’s important to ensure that puberty isn’t delayed any longer than necessary and that hormones are introduced as soon as the person is ready. This may involve stopping the blockers and reverting to birth hormones or introducing hormones as medication. 

When hormones are reintroduced, evidence shows that bone density quickly catches up. Bone scans may also be a valuable tool to monitor bone density accrual to ensure it is sufficient when the maximum bone development has occurred. 

What Is a Bone Scan?
Bone Scans and their Relation to Puberty Blockers for Transgender Youth

A bone scan (also known as a DEXA scan) is a low-dose X-ray imaging test that measures bone density, or the strength of the bones. The scan identifies the mineral content of the bones in specific locations of the skeleton, enabling bone loss to be measured.

When Is a Bone Scan Needed? 

Some experts advocate for a baseline bone scan prior to the commencement of puberty blockers. Bone density can then be monitored while youth are on puberty blockers. Once hormones are reintroduced and puberty restarts, there becomes less indication to monitor bone density. It is important to note that there is no official medical evidence to support the need for this investigation. 

Indeed, given that puberty blockers are introduced to block the progression of puberty, checking a patient’s bone density before starting HRT may just show the expected results for someone who has not yet hit that development milestone. We understand that density will improve with hormones, so why is there the need to check it? 

When on puberty blockers, bone density results are usually in the expected range of the gender assigned at birth prior to starting HRT. Scans do show that density catches up when hormones are initiated. 

The actual concern is how long it is safe to be on blockers without the introduction of hormones and whether the bones will always fully catch up — if puberty is blocked for an unnaturally prolonged period. 

What Is Our Opinion on Bone Scans? 

Physicians have differing opinions about the need for a baseline bone scan.

GenderGP believes that a baseline scan is ineffective for most transgender children because their bone density growth period will not have begun before they start puberty blockers. Of course, there are some exceptions, such as a family history of non-traumatic bone fractures, and your child’s unique medical history may necessitate a baseline scan. In general, though, a baseline scan will not provide you with any useful information as a one-off investigation. 

The course to medical transition is puberty blockers > introduction of hormones > bone density recovery.

At GenderGP, we do not believe that bone scans are necessary before starting puberty blockers unless there are specific risk factors, such as a family history of non-trauma bone fractures or risk factors for osteoporosis. This is based on clinical experience and data from major guidelines from all over the world.

Taking into consideration the fact that bone scans are not a usual investigation that can be easily done, GenderGP will recommend a bone scan only if there is a significant risk factor that shows there is a risk to a young person’s bone health. If you would like us to help organise a bone scan, we are very happy to write to your healthcare provider regarding this. 

The longer someone is on blockers alone, the higher the theoretical risk of bone problems. With the introduction of affirming hormones or stopping puberty blockers to allow natural puberty to happen, there is no perceived risk to bone health. 

The UK NHS system undertakes this investigation on all young patients. Some patients are forced to come off blockers and let puberty resume for the scan to occur. The evidence for this approach is not clear. 

What Do the International Guidelines Suggest? 

UCSF Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People

There are potential benefits of baseline information about bone density, although no consensus about the necessity of obtaining bone densitometry prior to, and during, GnRH analogue administration exists. If there is a family history of non-traumatic bone fractures, or osteoporosis, baseline screening is recommended.

This is in line with the advice that bone scans should not be done for everyone but resorted to when needed on a case-by-case basis.

The Endocrine Society 

  • For transgender males, baseline bone mineral measurements are generally in the expected range for their pretreatment gender.
  • For transgender females, consider bone scans at baseline. 
  • Recommend obtaining bone scans in transgender adults when risk factors for osteoporosis exist.


There is no mention of baseline bone scans. Only that physical development should be carefully monitored, preferably by a pediatric endocrinologist, so any necessary interventions can occur if any concerns arise. 

Australian Standards of Care 

Bone mineral density is on the list of tests to be done before commencing puberty blockers and then every 12 months until therapy is completed or as needed.

The American Academy of Pediatrics 

There is no mention of baseline bone scans.

International Guidelines Summary

  1. UCSF and The Endocrine Society both recommend baseline screening when there is a positive family history or the presence of risk factors for osteoporosis. 
  2. The Endocrine Society leaves it for the treating physician to consider baseline bone mineral density in transgender females but leaves out transgender males. 
  3. Australia recommends baseline bone scans for every person.


The important consideration is how long a young person will be on blockers without hormones. As a general rule, low readings should be expected in adolescents on blockers for any length of time due to the requirement for hormones to support bone development. 

When hormones are introduced, bone density is likely to catch up with expected strength. Bone scans can be helpful in some situations, particularly when risk factors are present, but they should not be regarded as a reason to prevent — or a requirement to start — gender-affirming treatment.

Puberty blockers are part of positive, gender-affirming healthcare, and there are no negative side effects to be concerned about, only information to be aware of. Trans youth seek gender-affirming care because they are transgender and have the same right to health and healthcare as everyone else.

To access health and wellbeing services for your child or young person, schedule a discovery session with one of our gender specialists.




Photo by Ben Wicks on Unsplash