Several studies have now shown that the human body remains in its biological sex upon birth even after transgender therapy.
Studies from the Boston University's School of Medicine in Massachusetts, the Institute of Endocrinology and Metabolism at Tel Aviv-Sourasky Medical Center in Tel Aviv, Israel, and UPMC Magee-Womens Hospital and UPMC Children's Hospital in Pittsburgh, Pennsylvania have shown how people's assigned sex at birth is retained no matter how many procedures to remove body parts or hormone therapy they undergo.
A study conducted by researchers at the Boston University's School of Medicine has found that the body of a biological male will fight to preserve the chemical balances that make him a man despite testosterone therapy. The study published in the journal Endocrine Practice was the "first to investigate the efficacy of transgender treatment in terms of achieving targeted and subsequent stability of testosterone levels achieving over a prolonged period of several years," Eurekalert reported. When transitioning from male to female, patients undergo medication and surgery to decrease or suppress testosterone levels to lower it to match the female range.
The study analyzed how the human body retains biological sex even through transgender therapy by analyzing 98 anonymized transgender women who were treated with oral spironolactone and oral estrogen therapy.
According to standards, patients should be able to reach a testosterone level of <50ng/dl, the usual female physiologic range. Among these study subjects, only 25% were able to do so following spironolactone and estrogens therapy. More interestingly, another 25% could not achieve these female levels and remained below the male range, while 25% were unable to exhibit any significant suppression.
According to The Washington Gazette, another study found that women who undergo testosterone therapy to undergo transition from male to female can in fact still get pregnant if they failed to surgically remove their female body parts. They also give birth the natural way, as normal females do. Furthermore, transgender men or biological females even breastfeed their babies even if they had undergone breast removal surgery.
In 2019, a study conducted by researchers from the Institute of Endocrinology and Metabolism at Tel Aviv-Sourasky Medical Center found that despite undergoing a year of testosterone treatment as part of transgender therapy, "ovary function is preserved to a degree that may allow reproduction," Dr. Yona Greenman a deputy director at the institution, explained.
Eurekalert reported that the study was conducted on 52 transgender men aged 17 to 40 who were receiving testosterone therapy over 12 months. Researchers tracked hormone levels in the study subjects' blood and they underwent a pelvic ultrasound to measure ovarian factors that reflect fertility.
Results revealed that despite the expected increase in testosterone blood levels and decrease in estrogen following a year in transgender therapy, participants still had a normal range of fertility as measured by the levels of anti-Mullerian hormone (AMH) secreted by the ovarian follicles.
Greenman explained that the levels of anti-Mullerian hormone (AMH) found among these trans men undergoing transgender therapy "indicates well-preserved ovarian function."
Conversely, another study revealed how men who used hormonal therapy to transition into women were still able to produce sperm upon stopping treatment and what's even more amazing is that the quality of sperm was unaffected by transgender therapy, meaning that the human body resisted the change and remained its biological sex.
According to Eurekalert, the study was conducted by researchers at the UPMC Magee-Womens Hospital and UPMC Children's Hospital and the results were published in the journal Pediatrics. Lead author Dr. Hanna Valli-Pulaski warned, "Going on and off gender-affirming medications can cause psychological distress in this population and it's important patients have a discussion with their health care provider before starting or stopping any treatment."
These studies simply reveal that the human body knows its own biological sex - and no amount of treatment or therapy can force it to become what it isn't.