The Evolution of Transgender Medicine

Farah Naz Khan, MD

By Farah Naz Khan, MD

What does it mean to be transgender? It’s a question that many people are asking since the increase in visibility of those who consider themselves transgender or gender non-conforming.

More than one million Americans identify as transgender, but what this classification actually means can often be confusing. When a person identifies with a gender other than their biological sex at birth, a condition called “gender dysphoria,” in which a person experiences discomfort or distress because there’s a mismatch between their biological sex and gender identity, they are transgender. Establishing this identity is the first step on the gender transition journey, which can begin at any age. But this journey can often be physically, mentally and emotionally taxing, requiring that stable support systems be in place before the journey can begin.

Transgender healthcare: where to begin?

The roots of transgender healthcare began in the early 1900s when German physician Magnus Hirschfeld, often considered the most important early pioneer of studies of sexuality, established the Institute for Sexual Science in Berlin. Severaldecades later, endocrinologist Harry Benjamin laid the foundation for modern American transgender healthcare by writing the first textbook on the subject in 1966, “The Transsexual Phenomenon.” With these two pioneers having laid the groundwork for transgender health care, physicians today are better equipped with the therapies needed to help patients begin their gender transition through either medical therapies, surgical changes, or both.

Once a person decides to begin their transition from their biological gender to the gender they truly identify with, establishing a relationship with a physician is key. Typically, medical endocrinologists specialize in transgender health care and can help initiate the needed medical therapies after the patient-doctor relationship has been established.

Generally speaking, those who are male by sex at birth have more testosterone than those who are female by sex at birth. Similarly, those who are female by sex at birth have more estrogen than those who are male by sex at birth. These hormone level differences help shape many of the physical, mental and emotional characteristics that we usually associate as the differences between men and women.

Thus, to help a patient who was born male by sex but identifies as female, we start estrogen therapy along with medications that can reduce their natural testosterone levels. Conversely, to help a patient who was born female by sex but identifies as male, we begin testosterone therapy. After these therapies are started, doctors monitor hormone levels and the clinical effects of the medications. Based on the changing hormone levels and on the patient’s experience, these medications can be increased or decreased in dosage as needed.

What to expect with hormone therapy

For female-to-male transgender persons:
Testosterone therapy is commonly administered via either skin patches, topical gels, or through intramuscular injections. After starting testosterone therapy, patients can expect to see the beginnings of masculinizing physical changes within three months. These changes include the end of menstrual periods, increased muscle mass, fat redistribution, increased oiliness of skin, and increased facial and body hair. Within 12 months of testosterone treatment, further physical changes that some patients may see include increased strength, clitoral enlargement, voice changes and male-pattern hair loss.

For male-to-female transgender persons:
Most commonly, estrogen therapy can be found in pill form, skin patches, or topical gels, creams, or sprays, while testosterone-lowering medications are almost always administered as pills. After starting estrogen therapy and testosterone-lowering medications, patients may see physical feminizing changes in the first few months that include decreased facial and body hair, decreased oiliness of skin, breast growth, and fat redistribution. Maximal breast development can be expected after two years of hormone therapy, and with even more time, the prostate and testicles will become smaller in size. There are no voice changes noted with estrogen and anti-androgen therapies.

Potential complications of hormone therapy

As with any medications, there are risks and benefits associated with hormone therapy for transgender patients. In addition to improvement in symptoms of gender dysphoria, the benefits include the changes noted above, while the risks include the medication side effects along with the potential to make pre-existing medical conditions worse.

For transgender females on medical therapy, estrogen therapy is associated with an increased risk of blood clots (ranging from deep vein thromboses in the lower extremities to blood clots in the lungs that can be medical emergencies). Additionally, estrogen therapy can cause serious adverse effects in patients with liver disease, breast cancer, heart disease, migraine headaches and those with a history of stroke. Testosterone therapy for transgender males carries the potential to worsen liver dysfunction and a condition known as erythrocytosis, whereby the red cells in the blood begin to significantly outnumber the other blood cells. Additionally, testosterone therapy can worsen symptoms of congestive heart failure and sleep apnea.

The role of surgery for transgender patients

While the hormonal therapies mentioned above will have a modest effect on the internal and external sex organs that patients are born with, they will not be able to alter these organs completely. This is why some transgender patients consider undergoing gender confirmation surgeries. For many transgender patients, surgery is often considered the final step in their journey to live fully and completely as the gender they most identify with.

Gender confirmation surgeries typically involve both the removal of internal sex organs and cosmetic surgery to change the external appearance of the genitalia. These surgeries can often lead to improvement in the mental health of transgender patients, but these are highly specialized surgeries that are only performed at a few select centers in America.

Where can you learn more?

If you still have questions about what it means to be transgender or if you want to learn more about transgender health care, the following websites are very useful resources:

  1. Fenway Health Transgender Program:
  2. My Trans Health:
  3. The International Foundation for Gender Education:
  4. World Professional Association for Transgender Health (WPATH):
  5. Renaissance Education Association: