Puberty blockers are a safe and effective way to treat precocious puberty and gender dysphoria.

parent and child huggingShare on Pinterest
The Good Brigade/Getty Images

Typically, puberty blockers alone do not cause permanent changes. But this can vary depending on several factors, including any medical conditions a person has, when they start puberty blockers, how long they take this medication, and whether they also take gender affirming hormones.

This is true whether the medication is being used to treat precocious puberty or as part of gender affirming care.

When a person stops taking puberty blockers, their body will resume puberty exactly as it would have if they had never taken the medication, says Jennifer Osipoff, MD, a pediatric endocrinologist at Stony Brook Children’s Hospital in New York.

Puberty blockers have been specifically used for decades to successfully delay the early onset of puberty in children with unusually early puberty.

You may have learned about puberty blockers because of their role in gender affirming care.

But pediatric endocrinologists have been using these medications for many years to treat precocious puberty, says Osipoff.

Precocious puberty is puberty that happens earlier and more quickly than is considered healthy, she explains.

In children assigned female at birth (AFAB), that’s before age 8, and in children assigned male at birth (AMAB), that’s before age 9.

Puberty blockers tell your brain to stop releasing puberty hormones.

In AFAB folks, puberty blockers typically decrease the production of estrogen. This stops breast development and halts menstruation.

In AMAB folks, puberty blockers typically decrease the production of testosterone. This stops the development of a deeper voice and facial hair, as well as testicle growth.

To understand exactly how puberty blockers work, you need to understand what’s necessary for puberty to take place.

“For a person to go through puberty, the hypothalamus has to release a hormone called gonadotropin-releasing hormone (GnRH), and it specifically has to release it in a pulsing fashion,” explains Osipoff.

When released in a pulsing fashion, GnRH tells another part of the brain, the pituitary gland, to make luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

These hormones, also known as gonadotropins, tell the ovaries or testes to make estrogen or testosterone, respectively.

Now, here’s where puberty blockers come in.

“Puberty blockers release GnRH in a steady-state fashion,” says Osipoff. Because GnRH is being released in a steady state rather than in a pulsing fashion, the pituitary gland never gets the signal to make LH or FSH.

Without LH or FSH, the ovaries or testes never get the signal to make estrogen or testosterone.

In other words, the body makes fewer sex hormones. And because sex hormones are needed for people to go through puberty, puberty stops.

It depends on whether the stop coincides with the start of gender affirming hormones.

If no other medication is prescribed, puberty will resume exactly as it would have without the blockers.

AFAB folks will likely develop breasts and begin menstruating, while AMAB folks will likely start to develop an Adam’s apple and grow facial hair.

According to Osipoff, the amount of time it takes for a person to resume puberty varies.

“It’s similar to how people’s bodies respond differently when they go off birth control pills,” she says. “Some people take a few weeks, while some people take just a few days.”

If a doctor prescribes gender affirming hormones, the person will begin puberty as the gender they are, not as the sex or gender they were assigned at birth.

Yes. Puberty blockers are widely considered safe.

None of the medications used to block puberty have been recognized by the Food and Drug Administration (FDA) as official treatments for gender dysphoria, but the FDA has declared that these medications are safe when used as prescribed.

The FDA approved the first puberty-blocking medication — a GnRH analog drug called Lupron — in 1993 to treat precocious puberty.

Puberty blockers can be lifesaving.

Going through puberty that causes you to develop physical attributes that aren’t aligned with your gender identity is emotionally and mentally distressing, says Jonah DeChants, a research scientist with The Trevor Project.

Not to mention, it can be alienating, disembodying, and possibly traumatizing.

“Puberty blockers are lifesaving for transgender, nonbinary, and gender questioning youth because they prevent these kinds of changes,” says DeChants.

Notably, puberty blockers stop elements of puberty that are permanent or would require intensive surgeries or therapies to address.

“Just as it would be distressing for a cisgender boy to grow breasts (which does happen and is treated) or for a cisgender girl to grow a beard (which also happens and is treated), it can be deeply distressing for trans girls to develop facial hair and trans boys to develop breasts,” explains DeChants.

But the benefits go beyond saving people the money, hassle, and risk associated with surgery and other therapies.

A 2020 study conducted by the American Academy of Pediatrics found that transgender adults who took puberty blockers as adolescents experienced significantly less lifetime suicidal ideation than trans people who wanted these medications but could not access them.

The researchers noted that these results aligned with past medical literature, suggesting that prescribing puberty blockers to interested transgender youth has a positive effect on overall mental health and well-being.

To help put these benefits into perspective, it’s important to acknowledge that rates of suicide and suicidal behavior are highest among transgender children and adolescents.

In one 2020 study involving 372 transgender youth, 86% reported that they had considered suicide, and 56% reported that they had attempted suicide.

The lifesaving impact of these medications can’t be overstated.

The risk is reduced quality of life for these young people.

“Puberty blockers improve a young person’s quality of life by preventing potentially permanent changes associated with puberty, which may be very distressing for youth experiencing gender dysphoria,” says DeChants.

“They also give youth, their doctors, and families the time and space to determine what future gender affirming healthcare may be best for them, if any at all,” he says.

Broadly speaking, the potential side effects are minimal.

“Puberty blockers are typically administered via intramuscular injection or a surgical implant,” explains Osipoff. As with any injection or implant, irritation and infection are possible.

The other main side effect of puberty blockers is that the medication may affect bone health. More research is needed to truly understand this potential impact.

“The sex hormones have a direct effect on the strength and density of bones and bone formation,” explains Osipoff.

Because puberty blockers disrupt and ultimately lessen the production of certain sex hormones, these medications may negatively affect bone mineral density when taken for a prolonged period.

Many healthcare professionals prescribe a calcium supplement alongside puberty-blocking medication to help counteract this potential side effect. They also monitor for any negative changes.

If your bone health has been negatively affected, it will likely improve once you stop taking puberty blockers or start taking gender affirming hormones.

Puberty blockers alone do not affect fertility. However, fertility may be affected if gender affirming hormones (such as testosterone or estrogen) are added. Fertility preservation options may also be limited depending on what stage of puberty you are in when starting blockers.

Children who are prescribed puberty blockers to treat precocious puberty typically take the medication until they’re at least 8 or 9 years old.

There are cases of people presenting with signs of precocious puberty as young as 1 year old who then use this medication for 7 or more years, explains Osipoff.

“There isn’t a clear-cut answer for how long puberty blockers will be used when used as part of transgender or gender affirming healthcare,” she says.

What are puberty blockers?

Puberty blockers are drugs that doctors prescribe to stop puberty.

Are there different types of puberty blockers?

No. The medication is the same for people all across the sex and gender spectrum.

“The puberty blocker medication taken is the same for everyone because it works at the level of the brain,” explains Osipoff.

How long until puberty blockers take effect?

Puberty blockers work immediately.

“People will notice changes pretty darn quickly because the medication immediately leads to a decrease in sex hormones,” says Osipoff.

At what age can you start taking puberty blockers?

While there is no age minimum, healthcare professionals will typically start prescribing them for treatment of gender dysphoria at Tanner Stage 2. For people with ovaries, this is marked by the beginning of breast bud growth. For people with testicles, it occurs when the testicles and penis start to enlarge.

How do you get puberty blockers?

If you or an adolescent in your care is interested in taking puberty blockers, you can start the process by consulting a gender affirming pediatrician, endocrinologist, or other healthcare professional.

The healthcare staff at Planned Parenthood, for example, can help you find a clinic in your area or refer you to a nearby specialist.

The effects of puberty blockers are not permanent. If a person stops taking puberty blockers, the effects of puberty will return or resume.

Depending on the person’s sex assigned at birth and individual genetic makeup, this may include breast development, facial hair growth, voice changes, and menstruation.

If a person stops taking puberty blockers, puberty will begin.

If a person also receives hormone therapy, the effects of puberty will be aligned with their identity rather than the sex they were assigned at birth.


Gabrielle Kassel (she/her) is a queer sex educator and wellness journalist who is committed to helping people feel the best they can in their bodies. In addition to Healthline, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.