Transmasculine Hormone Therapy

Masculinizing hormone therapy, also known as transmasculine hormone therapy, or female-to-male (or FTM) hormone therapy, is a form of hormone therapy and gender affirming therapy which is used to change the secondary sexual characteristics of transgender people from feminine or androgynous to masculine. It is a common type of transgender hormone therapy (another being feminizing hormone therapy), and is predominantly used to treat transgender men and other transmasculine individuals. Some intersex people also receive this form of therapy, either starting in childhood to confirm the assigned sex or later if the assignment proves to be incorrect.

The purpose of this form of therapy is to cause the development of the secondary sex characteristics of the desired sex, such as voice deepening and a masculine pattern of hair, fat, and muscle distribution. It cannot undo many of the changes produced by naturally occurring puberty, which may necessitate surgery and other treatments to reverse. The medications used for FTM therapy include, mainly, androgens (namely testosterone) and GnRH analogues.

While the therapy cannot undo the effects of a person's first puberty, developing secondary sex characteristics associated with a different sex can relieve some or all of the distress and discomfort associated with gender dysphoria, and can help the person to "pass" or be seen as their gender identity. Introducing exogenous hormones into the body impacts it at every level and many patients report changes in energy levels, mood, appetite, etc. The goal of the therapy, and indeed all somatic treatments, is to provide patients with a more satisfying body that is more congruent with their gender identity.

Masculinizing hormone therapy has been shown to likely reduce the distress and discomfort associated with gender dysphoria.

Medical uses

* To produce masculinization and/or defeminization in transgender men and genderqueer individuals.
* To produce masculinization and/or defeminization in intersex people.

Requirements and accessibility

Contraindications

Several contraindications to androgen therapy exist. An absolute medical contraindication is pregnancy.

Relative medical contraindications are:
* Androgen-sensitive epilepsy
* Migraines
* Sleep apnea
* Polycythemia (elevated red blood cell count)
* Cardiac failure, renal failure, or severe hypertension susceptible to sodium retention and fluid overload
* Significant liver disease
* Coronary artery disease or risk factors for this condition
* History of uterine cancer
* Bleeding disorders (for injected testosterone)
* Significant history of violent behavior
* History of breast cancer (testosterone has antiproliferative effects on most but not all breast cancers)
* Acne (mild to severe)

Safety

Two recent studies indicate the potential for elevated risk of cardiovascular events. Nota, et al. (2019) found that transgender men taking testosterone had an increased risk of cardiovascular events compared to cisgender women, with 11 vs. 3 cardiovascular events per 100,000 person-years, though the risk was less than that of cisgender men. Researchers were not able to control for smoking status or stressors.
Another recent study (Alzahrani, 2019) found elevated risk of heart attacks among self-identified transgender men—which persisted even after adjusting for age, diabetes mellitus, chronic kidney disease, smoking, hypertension, hypercholesterolemia, and exercise—though the study did not include data about whether the subjects were undergoing hormone therapy and did not control for stressors. The study found that transgender men have a >4-fold and 2-fold increased odds of having a myocardial infarction when compared with cisgender women and cisgender men, respectively. Though it is not always the case, testosterone for transmasculine people is often intended to be used long-term. Due to insufficient comprehensive research, there is no consensus on the full range of risks of lengthy testosterone administration.

Some transgender men may undergo DIY treatments and self-administer testosterone; however, without proper training, this can cause issues such as bruising, irritation, and needle breakages. Self-administration of testosterone for transmasculine people without training or a prescription is considered unsafe and is not recommended by public or private healthcare providers. It may also be illegal.

Interactions

Testosterone is metabolized by the cytochrome P450 enzyme system (specifically CYP3A isoforms) in the liver. There are certain drugs that increase or decrease the activity of cytochrome P450 enzymes and may cause increased or decreased levels of testosterone:
* Enzyme inducersMay cause decreased levels of testosterone (and other sex steroid) levels: Phenobarbital and phenytoin (seizure medicines), rifampin (antibiotic), and alcohol.
* Enzyme inhibitorsMay cause increased levels of testosterone: Nefazodone, fluoxetine, paroxetine (antidepressants), itraconazole, fluconazole, and other azole antifungals, cimetidine (an anti-ulcer agent that can cause gynecomastia in men because of this effect). Clarithromycin and other macrolide antibiotics, and protease inhibitors (HIV treatment).

Testosterone can also alter the effects of other drugs:
* Increases the blood thinning effect of warfarin;
* Decreases the effectiveness of propranolol, a nonselective beta blocker used in the management of cardiovascular conditions;
* Increases the effect of some oral medicines for diabetes and can cause dangerously low blood sugar levels.

Because of these interactions, it is advised that trans men make their healthcare providers aware of their hormone therapy when this is relevant to their treatment for other medical issues.

Medications

Medications used in hormone therapy for transgender men include androgens and anabolic steroids like testosterone (by injection and other routes) to produce masculinization, suppress estrogen and progesterone levels, and prevent/reverse feminization; GnRH agonists and antagonists to suppress estrogen and progesterone levels; progestins like medroxyprogesterone acetate to suppress menses; and 5α-reductase inhibitors to prevent/reverse scalp hair loss.

Testosterone

The elimination half-life of testosterone in the blood is about 70 minutes, so it is necessary to have a continuous supply of the hormone for masculinization.

Injected

'Depot' drug formulations are created by mixing a substance with the drug that slows its release and prolongs the action of the drug. The two primarily used forms in the United States are the testosterone esters testosterone cypionate (Depo-Testosterone) and testosterone enanthate (Delatestryl or Xyosted) which are almost interchangeable. Testosterone enanthate is purported to be slightly better with respect to even testosterone release, but this is probably more of a concern for bodybuilders who use the drugs at higher doses (250–1000 mg/week) than the replacement doses used by transgender men (50–100 mg/week). These testosterone esters are mixed with different oils, so some individuals may tolerate one better than the other. Testosterone enanthate costs more than testosterone cypionate and is more typically the one prescribed for hypogonadal males in the US. Testosterone cypionate is more popular in the US than elsewhere (especially amongst bodybuilders). Other formulations exist but are more difficult to come by in the US. A formulation of injected testosterone available in Europe and the US, testosterone undecanoate (Nebido, Aveed) provides significantly improved testosterone delivery with far less variation outside the eugonadal range than other formulations with injections required only four times yearly. However, each quarterly dose requires an injection of 4 mL of oil which may require multiple simultaneous injections. Testosterone undecanoate is also much more expensive as it is still under patent protection. Testosterone propionate is another testosterone ester that is widely available, including in the US, Canada, and Europe, but it is very short-acting compared to the other testosterone esters and must be administered once every 2 or 3 days, and for this reason, is rarely used.

The adverse side effects of injected testosterone esters are generally associated with high peak levels in the first few days after an injection. Some side effects may be ameliorated by using a shorter dosing interval (weekly or every ten days instead of twice monthly with testosterone enanthate or testosterone cypionate). 100 mg weekly gives a much lower peak level of testosterone than does 200 mg every two weeks, while still maintaining the same total dose of androgen. This benefit must be weighed against the discomfort and inconvenience of doubling the number of injections.

Injectable forms of testosterone can cause a lung problem called pulmonary oil microembolism (POME). Symptoms of POME include cough, shortness of breath, tightening of the throat, chest pain, sweating, dizziness, and fainting. A postmarketing analysis by the manufacturer of Aveed (testosterone undeconate injection) found that POME occurred at a rate of less than 1% per injection per year for Aveed.

Injected testosterone esters should be started at a low dose and titrated upwards based on trough levels

HOME


Content is Copyleft
Website design, code, and AI is Copyrighted (c) 2014-2017 by Stephen Payne


Consider donating to Wikimedia



As an Amazon Associate I earn from qualifying purchases