Is there anything natural about stopping normal puberty? Would you stunt a child’s normal eye development to make tiny eyes in an enlarging head? Would you stop a child’s limb development so that the torso lengthens, but arms and legs remain stunted? This sounds bizarre, because it is. But it is analogous in many ways to the ongoing experiment in stopping normal puberty.

A recent high-profile custody case in Texas—in which a mom is advocating the transitioning of her seven-year-old son James into a girl named Luna, against the wishes of his father—has brought the issue of child transition and puberty blockers to the attention of everyday Americans, elected officials, and people around the world. What has gone less noticed is the backing of the medical establishment. Professional societies are now promoting these untested treatments as solid, evidence-based science.

Approximately two weeks after James’s plight garnered international attention in late October, the Pediatric Endocrine Society (PES) issued a statement regarding medical therapy for children who are uncomfortable with their sexed bodies. In that document, the organization states that the effects of puberty-blocking medications are reversible. Other organizations such as the American Medical Association are leading kids toward these harmful drugs by supporting bans on therapies that aid children in becoming comfortable in their natural bodies.

But do we know with certainty that all of the effects of the medications for stopping normal puberty are fully reversible? Has the FDA determined that there is scientific evidence to validate this claim? Have there been any rigorous long-term studies addressing this question? Is social transition truly harmless? Is it ethical to continue this experiment on children?

The answer to all of those questions is no.

An Urgent Public Health Problem

Puberty is more than just a process of genital maturation. It is also a critical time for bone, pelvis, brain, and psychosocial development. All of these processes are adversely affected by puberty blockers. Studies have shown the effects on the pituitary are not immediately reversible. Hormonal levels do not normalize until a year or more after stopping blockers, which prolongs pubertal delay. And, although the studies on this are limited, the data we do have indicate that the overwhelming majority of adolescents on puberty blockers decide not to reverse course, but instead move on to cross-sex hormones and then to sterilizing genital surgeries. This is in marked contrast to the experience of children who experience gender dysphoria but are allowed to go through puberty normally, the vast majority of whom do not persist in identifying with the opposite sex.

This is an urgent public health problem. In the United States, at least sixty-five gender clinics have sprung up . In 2007, there was one. As many as 3 percent of school kids now identify as transgender. In the United Kingdom, the Tavistock’s gender clinic had a more than 5,000 percent increase in referrals of girls in less than a decade.

What follows is a detailed description of puberty blockers within the context of the ever-increasing medicalization of gender-atypical youth, beginning with an analogy for the purposes of understanding normal pituitary function.

The Signaling Mechanism

The pituitary is a small but extraordinarily important little gland that sits behind the eyes and is attached to the brain. It is sometimes called the “master gland,” as it controls other glands—including the sex glands, the testicles of males and ovaries of females. To understand how this system works, consider the following analogy.

Imagine a package delivery system. There is a Management Office, where the idea for sending a package originates. The office manager walks down to a Courier’s Office to deliver a note. The Courier’s Office receives the note and then types up a new message, which is given to a courier. The courier hand-delivers this message to a warehouse. Once it is received, a truck driver leaves to deliver the package.

In the body, the Management Office corresponds to an area of the brain called the hypothalamus. It sends a signal (called GnRH) to a Courier’s Office, which is located in the pituitary gland. This Courier’s office creates a new message (called luteinizing hormone or LH) which in turn is delivered to the gonad. Once the message is received, the gonad makes and releases its sex hormone (like the driver delivering the package). In a man, the testicle releases testosterone. In a woman, the ovary releases estrogen. The sex hormones then allow for normal pubertal development.

How Lupron Stops Puberty

To understand what happens if we administer a puberty-blocking agent, such as Lupron, let’s introduce another concept. Let’s say there are many identical office managers. Each office manager needs a key to deliver their message to many identical, locked Couriers’ Offices.

Let’s say there were originally one thousand locks. Then imagine that someone stuck a foreign object into 999 of them, jamming them and preventing the keys from working. In this case, it would not matter how many office managers had working keys. There would still be only one available keyhole. Only one courier could deliver his note, and only one driver would deliver a package.

In endocrinology, we call this downregulation. A medication like Lupron acts like a key, bringing a message to the pituitary. The pituitary reacts by reducing the number of “locks.” These locks correspond to cellular receptors, and their numbers are drastically reduced by the administration of Lupron.

Blocking the action of the pituitary gland and drastically lowering sex hormones in this way effectively “freezes” pubertal development. It is the creation of the disease state called hypogonadotropic hypogonadism by means of medication.

Is This Reversible?

If Lupron is stopped, what happens? In theory, over time, the receptors should increase to a normal count, and then signaling can proceed normally. Estrogen and testosterone should then be released normally and puberty allowed to continue. It’s as if a locksmith came along and gradually repaired the 999 inoperable locks. This would allow the rest of the couriers to deliver their messages and prompt the drivers to deliver their packages.

This idea is employed in the treatment of central precocious puberty. Central precocious puberty is an abnormal condition in which puberty begins at a very early age—say, age four. The FDA has approved the use of Lupron for this condition. Once the child is older—say, eleven—the medication is stopped to allow normal signaling to proceed and sex hormones to be released. After an additional delay of twelve to eighteen months, the child’s body can advance through more typical adolescent puberty.

But what happens if we block normal puberty? Bear in mind that the FDA has not approved the use of Lupron or similar agents for stopping normal puberty. There have been no randomized controlled studies for this use. And the limited safety studies that have been conducted have shown a number of potential problems.

Puberty Involves Bone, Brain, and Psychological Milestones

In normal male pubertal development, the penis will enlarge and develop erections and ejaculation capability. Mature sperm will be produced, which are capable of fertilizing an egg or ovum. In the female, the pelvic genitalia (including labia, vagina, and uterus) and breasts will develop and mature. Ovulation will begin to occur, and an egg capable of being fertilized will be released during each menstrual cycle.

When puberty is blocked with Lupron, all of these pubertal changes are disrupted. The genitals remain “frozen” in whatever stage of pubertal development they had reached when the medication regimen began.

This is widely known. What people don’t usually consider is that puberty is also extraordinarily important in female pelvic maturation, and in the normal bone structure and brain development of both sexes. Additionally, the physical changes of puberty occur in the wider context of complex developmental milestones as the child progresses toward social independence from his or her parents.

Disruption of a temporal process of development cannot be reversed. As pediatric endocrinologist Paul Hruz and colleagues discerningly state, “Rather than claiming that puberty suppression is reversible, researchers and clinicians should focus on the question of whether the physiological and psychosocial development that occurs during puberty can resume in something resembling a normal way after puberty-suppressing treatments are withdrawn.”

A Critical Period of Bone Density Development

Pubertal development is a time of rapid increase in bone density or strength. This period of bone density increase continues and hits a peak at around age twenty-five or thirty. A slow decline occurs thereafter. The use of puberty blockers to lower sex hormones close to zero interrupts this bone-strengthening process.

In puberty, both growth hormone and the sex hormones are necessary for proper bone development. Puberty blockers disrupt and decouple the timing of these hormones’ release. As a result, their actions are out of sync during pubertal development.

Thus, we would predict that the bones of adolescents who are administered puberty blockers would not become as dense and strong as expected. The limited studies that exist thus far confirm this hypothesis. For example, one study followed thirty-nine adolescent girls whose average age was about twelve-and-a-half when they began puberty blockers. Initially, they were in the 40th percentile for bone density. By the end of two years, however, they were in the lower 3rd percentile for bone density. This drastic decline in bone density is not surprising if one understands the critical role of the sex hormones in bone density development.

I strongly suspect that these young people will not meet their full adult potential for bone density, because they have lost valuable time during which their bones are supposed to be increasing in density and strength. This time cannot be recovered, putting them at serious risk for adulthood osteoporosis and fractures.

Female Pelvic Development

Significant differences exist between the adult male and female pelvises. The adult female pelvis is shaped in such a way as to allow room for a baby to pass through the birth canal. This is very important, because human babies have large heads to hold large brains relative to other mammals. Changes in the female pelvis begin to occur under the influence of estrogen during puberty. Sex differences between skeletons are not nearly as pronounced for children who have not finished puberty.

During puberty, the female pelvic inlet and outlet become wider and more oval-shaped, the pubic arch develops a significantly wider angle, and the sacrum (or tailbone) becomes less angled so as to not get in the way of the pelvic outlet.

When puberty blockers are used on a young girl, along with the drop in bone density relative to her peers, her pelvis will be “frozen” in a childlike configuration. It is not known if stopping puberty blockers by a certain age might still allow a window of opportunity for the female pelvis to reach optimal configuration for birth.

A pelvis that is not optimally configured for birth could put mother and baby at increased risk for obstructed labor. Obstructed labor is a condition in which the baby does not leave the pelvis during childbirth due to being physically blocked, even if the uterus is contracting normally. Complications include the baby not getting enough oxygen, which may result in death. For the mother, risks include infection, postpartum bleeding, uterine rupture, and obstetrical fistula.

Brain and Neuropsychiatric Development

The sex hormones are important and integral to adolescent brain development. Studies of animals show that the sex hormones “exert profound effects on brain maturation and behavior.” Though much is not yet known about exactly how the sex hormones work to develop the brain (which should already be a warning sign), studies have shown that the use of puberty-blocking medications can lead to memory impairment, slow reaction times, reduced long-term spatial memory, increased depressive symptoms, and a potential drop in IQ.

What about psychiatric effects? Using the Freedom of Information Act, Professor Michael Biggs of Oxford University has obtained unpublished study data from the Tavistock Gender Identity Development Service in the UK. He found that,

after a year on GnRHa [puberty blockers] children reported greater self-harm, and that girls experienced more behavioral and emotional problems and expressed greater dissatisfaction with their body—so puberty blockers exacerbated gender dysphoria.

These findings should not be surprising. One need only examine the labeling for Lupron to find very concerning neuropsychological effects. Reported side effects include emotional lability, mood changes, headaches, nervousness, anxiety, agitation, confusion, delusions, insomnia, and depression. The label cautions providers to “monitor for development or worsening of psychiatric symptoms. Use with caution in patients with a history of psychiatric illness.”

Note also that there have been a long series of lawsuits against the Lupron manufacturers and reports of patients developing disabling side effects.

So Much for a “Pause Button”

Proponents of puberty blockers present them as a simple “pause button,” whereby puberty can be stopped and restarted at the whim of physicians. But is this really the case?

In the absence of puberty blockers, signaling from the hypothalamus occurs at a preprogrammed time, triggering the start of normal puberty. We do not know if there is an endpoint to the window of time in which puberty can take place. In other words, if one stops normal puberty at age ten and then allows it to begin again at age fifteen, we do not know if the signaling mechanism will return fully. There is evidence to suggest that it will not.

In pharmaceutical testing of Lupron for the treatment of endometriosis in females and prostate cancer in males, research has shown that there is prolonged impairment of the pituitary even after the drug is no longer being administered.

An amicus brief to the Supreme Court in a lawsuit against the makers of Lupron cites the work of physician Dr. David Redwine, who “conducted an exhaustive review of Respondents’ TAP/Abbott’s clinical trials’ raw data.” What he found in examining the manufacturer’s internal data is quite astounding: “62.5 percent of patients had not regained baseline estrogen levels by one year after stopping Lupron.” This means that estrogen levels of the majority of these women had not returned to normal a full year after stopping the medication.

In a study of adult males who had used Lupron for the treatment of prostate cancer, it took a median average of nine months for testosterone levels to return to the normal range. However, a full 26 percent had failed to regain normal levels two years later.

These findings represent a major problem for the argument for puberty blockers as a “pause button.” If one is pausing a music track, one expects the music to resume immediately after pushing play again. However, once one “pauses” normal puberty with Lupron and then presses “play” again, there may be a delay of around a year or more before puberty returns. In some adolescents, it is possible that puberty may not resume at all, due to direct damage of the pituitary signaling mechanism. And even if it does “resume,” bone, brain, pelvic, and psychiatric development, as noted above, may never fully occur.

It Begins with Social Transition

What exactly is known about the limited number of adolescents who have undergone this experimental therapy? How many kids actually decide to stop these medications and “unpause” puberty?

Very few, it seems. In a Dutch study that included seventy adolescents who went on puberty blockers, all seventy decided to go on to further medicalizing by using hormones of the opposite sex. In a follow-up study, the majority went on to have “sex reassignment surgery” by either vaginoplasty for males or hysterectomy with ovariectomy for females—sterilizing them. One patient even tragically died of necrotizing fasciitis—otherwise known as the flesh-eating bacteria—due to the surgery. None of these seventy children actually paused puberty and then reversed course. Rather, they went full speed ahead into hormones and surgeries, each with a new set of dangers.

What I’ve described in this essay is the medical pathway to sterility. But that path begins even earlier than this, as in the case of children like seven-year-old James. It begins with “social transition.”

Social transitioning a child involves parents, therapists, teachers, and other persons in authority reinforcing the gender non-conforming child’s false belief that he or she is of the opposite sex “inside.” The mind manipulation involves compulsory use of opposite-sex pronouns, and employing rigid sex-based stereotypes in clothing.

Kenneth Zucker, an international expert in the field of childhood gender identity disorder, calls this intervention iatrogenic—an illness caused by a physician. He notes that “it should come as no surprise that the rate of gender dysphoria persistence will be much higher as these children are followed into their adolescence and young adulthood.” Since the child is deluded by continuously reinforcing the false belief about his or her sex, he or she is led to the next step of pubertal blockade to prevent the child’s innate capacity to grow up as an adult of his or her given sex.

In some cases, like James’s, one parent has aggressively pushed for the therapy. In many other cases, both parents are desperate for help for their child and are pressured or duped into the affirmative pathway by doctors, therapists, and school officials. Concerns about harms are minimized, and questions are seen as obstructive. Parents may even be threatened by the legal system and have their child removed from the home.

A Dereliction of Duty

There is nothing healthy about stopping normal puberty, because puberty is not a disease. The practice represents an unethical medical experiment with both known and unknown harms to adolescent development and to the human person, during a crucial time in a young person’s life.

The Pediatric Endocrine Society’s statement that puberty-suppressing agents are reversible is highly deceptive. Adolescents can never regain the years that are lost to the blockade of normal bone, brain, and pelvic development. Puberty may be inadvertently “paused” for an additional year or more after stopping puberty blockers, and the pituitary may never fully recover. Time lost for adolescents in developing into their sexed bodies with their peers and reaching psychosocial developmental milestones cannot be regained.

Children and adolescents suffering from confusion about their sexed bodies require compassionate care. We know that the vast majority of diagnosed children have been shown to desist or grow out of this condition if parents simply wait, rather than rushing to intervene. We should also recognize that a high percentage of adolescents with discomfort about their sex have underlying mental health disorders or neurodevelopmental conditions. Some smaller percentage may have suffered sexual, physical, or emotional abuse. These conditions need to be given first priority in diagnosis and treatment.

Puberty blockers should not be used as a treatment for a mental health condition. If anything, evidence from the UK’s Tavistock GIDS clinic indicates that these medications can worsen mental health outcomes for many kids. Counseling, psychological therapy, and support to help kids become comfortable with their sexed bodies, while allowing them to proceed through normal puberty, is the optimal course of treatment for them.

I would challenge the Pediatric Endocrine Society to take the time to investigate the full scope of known and potential harms for using puberty-blocking agents to stop normal puberty. In the meantime, there should be a moratorium on their use for this purpose. Not to do so is a dereliction of duty of the highest order. It is an abandonment of the fundamental principle to First Do No Harm.