Mick Hartley

As criticism mounts over the proposed puberty blocker test on children, here's an article in City Journal on the disastrous effects of cross-sex hormones – specifically the effects of oestrogen (aka US estrogen) on men:

In recent years, administering estrogen to males who identify as transgender women has become increasingly common, including among adolescents. Often paired with testosterone blockers, this treatment is marketed as part of “gender-affirming care”—a term used to describe medical interventions intended to “align” a person’s body with his or her “gender identity.” But as more young people pursue medical transition in the absence of long-term studies, concerns about safety, efficacy, and informed consent have grown more urgent.

A recent review article in Discover Mental Health, entitled “Emerging and accumulating safety signals for the use of estrogen among transgender women,” and authored by Lauren Schwartz and colleagues, tries to fill that gap. It compiles studies, case reports, and group data to spotlight a range of serious health risks—some well-known, others emerging—associated with long-term estrogen use in males.

So….infertility, obviously enough, together with damage to the testes. Also…

Cardiovascular complications are another well-documented concern. Multiple studies cited in the review report higher rates of dangerous blood clots—known as venous thromboembolism (VTE)—and strokes among trans-identifying males taking estrogen. One meta-analysis found VTE incidence more than twice as high as in non-trans-identifying males. A cohort study showed that after two years of estrogen use, the risk of VTE was over five times higher; after six years, the risk of ischemic stroke was nearly ten times higher than in non-trans-identifying males….

The paper also highlights potential cognitive risks, including memory loss and early-onset impairment. While short-term studies haven’t consistently shown problems, longer-term research on older transgender-identifying males taking hormones has found poorer performance on tasks involving memory and processing speed….

Perhaps the most alarming finding cited in the paper is the increased risk of early death. Schwartz and colleagues reference a Dutch cohort study of patients treated at a major gender identity clinic, which found that “the overall mortality risk of [trans-identifying men] . . . was higher compared to men in the general population . . . and even higher compared to women.” Leading causes of death included heart disease, cancer, and suicide. An earlier study found a 51 percent higher mortality rate in trans-identifying males than the general population. Notably, current estrogen use, rather than past use, was linked to these increased risks, suggesting long-term exposure to feminizing hormones may amplify health risks over time.

And that's not all.

Beyond these headline findings, the paper outlines several additional risks. Autoimmune diseases such as lupus and systemic sclerosis have occasionally appeared or worsened following the initiation of estrogen therapy. One patient with a skin-limited autoimmune condition developed life-threatening kidney complications after starting hormones. At the population level, males with gender identity disorders have been found to have a more than sixfold increased risk of developing multiple sclerosis—raising the possibility that estrogen may act as a trigger for autoimmune responses in some individuals.

Estrogen also appears to affect metabolism. Hormone therapy has been associated with increased fat mass, muscle loss, and reduced insulin sensitivity—an early warning sign for diabetes. In one study, insulin resistance rose by more than 80 percent over two years of use. Elevated triglycerides—a type of fat in the blood—have been linked to serious complications in trans-identifying males, including pancreatitis and gallstones.

The authors also review cancer risks. Trans-identifying males on estrogen are significantly more likely to develop breast cancer than non-trans-identifying men. One cited analysis estimated the risk to be 22 to 40 times higher. While breast cancer remains rare in men overall, such increases are noteworthy.

The paper also highlights elevated rates of thyroid and testicular cancers among trans-identifying males on estrogen. Some studies suggest a potential link between testicular cancer and long-term use of estrogen or testosterone blockers. Public drug safety databases in the U.S. and France reflect similar concerns, listing tumors, cardiovascular complications, and brain tumors—such as meningiomas—among the most frequently reported adverse events.

One especially unsettling section explores how estrogen may affect the male brain. A few small brain-imaging studies found that several months of estrogen use led to “an increase in ventricular volume and a decrease in brain volume.” Studies in male rats showed similar effects: estrogen and testosterone blockers reduced brain volume and altered brain chemistry. The authors suggest these changes may result from disruptions in how water is regulated in brain cells—potentially mimicking patterns seen in degenerative diseases.

The paper also notes that levels of BDNF—a brain chemical critical for mood and memory—tend to decline in patients on cross-sex hormones. Low BDNF is associated with depression and shrinkage of the hippocampus, a brain region essential for memory. Taken together, these findings raise the possibility that estrogen may produce lasting changes in male brain structure and function.

Not to worry. It's all part of "gender-affirming care".