Most transgender people in the US who take hormone medications do not experience serious side effects, but for those who do, the symptoms are usually life-threatening.
That is the conclusion of one of the first studies into the therapies, which have been increasingly used off-label in recent years to treat gender dysphoria.
The researchers analyzed the FDA’s Adverse Event Reporting System (FAERS) for side effects that occurred in transgender people who took the drugs to affirm their new gender.
They found just over 400 cases of adverse side effects, dating back to June 2023. Considering that at least 700,000 trans Americans are estimated to be using the drugs, the researchers say the true number of side effects is likely “underreported.”
Of the reports, up to 88 percent were the most serious type – including organ damage, cancer and death. The research team described this high number of serious events as ‘striking’.
Researchers found just over 400 cases starting at the start of the database through June 2023. The types of reactions shown were the most commonly reported of all side effects
The researchers – from Georgia and Utah – said their findings should be “interpreted with caution” because FAERS reports are voluntary and anyone can log one – including patients, family members, health care providers and vaccine manufacturers.
The reports are also unverified, meaning the medication did not necessarily cause the reaction mentioned, just that the patient or doctor believes there is a connection between it.
At the same time, however, the researchers said that “the voluntary nature of these reports may lead to underreporting, potentially underestimating the true incidence of adverse events.”
The FAERS system is intended as an early warning system for adverse events. However, the data must be carefully analyzed to determine whether patterns are caused by the drug or caused by another factor.
The latest analysis by pharmacists from the University of Utah and the University of Georgia is the first of its kind.
They examined 467 side effects of medicines.
The average age of trans men (female at birth and transitioning to male) was 29.5 years, while the average age of trans women was 33.3 years.
Of the side effects reported in trans men, 88 percent were categorized as serious, while this was 54 percent in trans women.
Most of these injuries reported in trans men – 26.5 percent – were injuries to organ systems, poisoning and complications such as infections, injection site bleeding and nerve damage.
Mental disorders accounted for 14.8 percent of adverse events in trans men, and nervous system disorders accounted for 12.2 percent.
In the group of health problems related to injuries, poisonings and procedural complications, the most common problem was “off label use of the product” (44 cases, or about 72.1 percent of all cases), although the researchers did not specify whether that was the case used to be. meant that people were taking the wrong doses or using the drugs too often or too little.
In terms of mental health problems, people reported feeling anxious (11.8 percent), depressed (8.8 percent) or having suicidal thoughts (8.8 percent).
Of the nervous system problems, a condition called idiopathic intracranial hypertension – a rare neurological condition characterized by increased pressure in the skull – was reported most frequently (18 cases, or about 64.3 percent).
About 11 percent of reported problems were related to growths in the body, with breast cancer being the most common (12 cases, or about 48 percent).
While this does not mean that supplemental estrogen was the cause of breast cancer in humans, studies have shown that higher blood levels of the estrogen called estradiol are associated with a increased risk of breast cancer in postmenopausal women.
In the category of problems related to the reproductive system and breasts, 17 cases were reported, accounting for approximately 7.4 percent of all cases.
In trans women (male at birth who transitions into female), a A significant number of adverse events (63 cases, which amounts to approximately 26.6 percent) were related to issues such as injuries, poisonings or complications resulting from medical procedures.
The most common specific problem in this category was the use of drugs in a way that is not officially approved (40 reports, accounting for approximately 63.5 percent).
About 11 percent of side effects were grouped under general disorders and conditions related to the site where the drug was administered.
In addition, almost 10 percent of reports fell into the category of tumors in the body (benign, malignant and unspecified), with meningioma and prolactin-producing pituitary tumors being the most common.
Nearly nine percent of the side effects involved mental disorders, including two cases of anxiety, seven cases of depression, one case of insomnia and one suicide attempt.
Among nervous system problems, headaches were the most common in three cases. Some other problems included dizziness, attention disorders, migraines, stroke and aphasia, all of which only affected one case.
Modern hormone therapies were first designed in the early 20th century to relieve menopausal symptoms, such as hot flashes and vaginal dryness, by replenishing declining hormone levels in women.
But in recent decades they have been prescribed off-label to people who experience gender dysphoria, or a sense of anxiety due to the discrepancy between the gender they were born into and the gender they most identify with.
Yet there have been no comprehensive studies of the long-term safety effects of these drugs in that patient group, and many neuroscientists and reproductive health experts have raised questions about their side effects and safety with long-term use.
Among trans men (female to male), 88 percent of reported side effects were considered serious
Hormone therapies can have a range of whole-body and system-wide effects that fall under this broad umbrella.
Introducing synthetic hormones or altering natural hormone levels can affect these systems, leading to side effects such as electrolyte imbalances, cardiovascular complications and immune-related reactions.
For example, some hormone therapies can increase the risk of heart complications, such as high blood pressure, blood clots, or heart rhythm disorders.
They can also potentially lead to irritation of the digestive tract, resulting in bleeding or holes in the intestines.
And problems with how the drugs are administered, such as incorrect injections, can lead to infections, tissue damage or incorrect dosing.
For events involving trans men, 88 percent were recorded by a healthcare professional, while 12 percent were recorded by the patient.
In cases of reporting about trans women, 67 percent of reporters were healthcare professionals, while about 30 percent came from a patient or loved one.
Hormone therapies are intended to give transgender people the secondary sex characteristics of their gender identity.
For transgender women, hormone therapy typically involves the administration of estrogen and anti-androgen medications, which suppress the effects of testosterone and cause feminizing changes such as breast development, redistribution of body fat, reduction of body hair, and softening of the skin.
For trans men, hormone therapy typically involves the administration of testosterone.
Testosterone promotes masculinizing changes such as deepening the voice, increasing muscle mass and strength, growing facial and body hair, and redistributing body fat.
But the drugs pose significant health risks, including those reported to the FDA.
The researchers said that while these treatments have helped thousands of gender dysphoric patients, they are prescribed off-label and their safety risks should never be underestimated.
They wrote: ‘It is imperative that the therapeutic goals for patients considering HT are clearly defined before initiating treatment.
‘This underlines the essential need for sound knowledge and understanding for both patients and their healthcare providers.’
This map shows the share of the population that identifies as transgender by state. Those with the darkest color have almost one percent of their population in this category
Rates of gender dysphoria have skyrocketed in every state bar over the past five years (pictured)
Experts at Mercy Catholic Medical Center in Darby, Pennsylvania, have found that trans patients taking the drugs are up to seven times more likely to have an ischemic stroke compared to trans patients who are not prescribed the drugs.
They were also almost six times more likely to have a myocardial infarction – the most serious type of heart attack – and had a five times higher risk of a pulmonary embolism, a blockage in an artery in the lung.
Both estrogen and testosterone are known to increase blood clotting activity, which could explain the increased risk.
Hormone therapies are also known to cause major changes in the emotional state of transgender people. For example, people taking estrogen may cry more than they are used to and even experience a greater sense of empathy. Some people may experience mood swings or a worsening of anxiety, depression or other mental health conditions.
However, there is also a large body of evidence showing that opening the door to gender-affirming care tends to lead to gender-affirming care improved quality of lifereduced depression and reduced anxiety.
The findings were published in the journal Annals of pharmacotherapy.