Masculinizing hormone therapy

Overview  

Masculinizing hormone therapy, also known as gender-affirming hormone therapy, involves using testosterone to induce physical changes in the body. These changes, known as secondary sex characteristics, are typically associated with male puberty. This treatment helps align a person’s physical appearance with their gender identity, promoting traits like a deeper voice, increased muscle mass, and more body hair.  

In addition to physical changes, masculinizing hormone therapy stops menstrual cycles and reduces the ovaries’ ability to produce estrogen. This therapy can be pursued on its own or combined with masculinizing surgery, depending on individual needs and goals. The decision to undergo such treatment is deeply personal and often part of a broader gender-affirming care plan. 

It’s important to note that masculinizing hormone therapy may affect fertility and sexual function, and it carries potential health risks. Individuals considering this treatment should consult with a healthcare professional to fully understand the benefits and risks, allowing them to make informed decisions about their care. 

Reasons for undergoing the procedure  

Masculinizing hormone therapy helps some people assigned female at birth, including transgender men and nonbinary individuals, feel more comfortable with their bodies. It can change their appearance and voice to better align with their gender identity.

Masculinizing hormone therapy can help in several ways, such as:  

• Address gender dysphoria  
• Enhance overall quality of life  
• Improve psychological well-being  
• Reduce emotional distress  
• Increase satisfaction with sex 

A healthcare provider may advise against masculinizing hormone therapy if a person is pregnant, has a hormone-sensitive cancer such as breast cancer, experiences blood clot issues like deep vein thrombosis or pulmonary embolism, has untreated significant medical or behavioral health conditions, or is unable to provide informed consent. 

Risk

Current evidence shows that those receiving masculinizing hormone therapy do not face an increased risk of breast cancer, endometrial cancer, or heart disease compared to cisgender women. 

Common complications associated with masculinizing hormone therapy include:  

• Elevated blood pressure  
• Overproduction of red blood cells, a condition known as polycythemia  
• Type 2 diabetes  
• Blood clots in deep veins or the lungs  
• Infertility  
• Higher levels of low-density lipoprotein (LDL), often referred to as “bad” cholesterol, and reduced levels of high-density lipoprotein (HDL), or “good” cholesterol, which could elevate heart disease risks  
• Sleep apnea  
• Sensitivity or discomfort in the clitoris  
• Increased body weight  
• Acne outbreaks  
• The onset of male-pattern hair loss  
• Thinning and drying of the vaginal lining  
• Pelvic discomfort 

The potential risks for ovarian and uterine cancers remain inconclusive, warranting further investigation. To minimize health risks, hormone levels should be maintained within the typical range for cisgender men.

Generally, research indicates that masculinizing hormone therapy is both safe and effective when administered by healthcare professionals experienced in transgender care.

Fertility 

Fertility decisions are best made before starting hormone therapy. Available options for individuals who undergo therapy but considers having biological children include:  

• Egg freezing or mature oocyte cryopreservation: Ovulation is stimulated, eggs are retrieved and subsequently frozen.   
• Embryo freezing or embryo cryopreservation: Before being frozen, eggs will be fertilized.   
• Ovarian tissue cryopreservation: Ovarian tissue is extracted, frozen, and later thawed for reimplantation.  

Generally, if the uterus and ovaries are still present and the individual has sex with someone who produces sperm, pregnancy remains possible. To avoid pregnancy, birth control is necessary.  

Masculinizing hormone therapy can decrease fertility, with the risk of permanent infertility increasing over long-term use, especially if started before puberty. Even after discontinuing the therapy, the ovaries and uterus may not recover sufficiently for pregnancy without fertility treatments.  

Procedure  

Masculinizing hormone therapy should only begin after a thorough discussion with an expert in transgender care, ensuring all risks, benefits, and treatment options are fully understood.

Prior to starting masculinizing hormone therapy, several assessments and procedures may be required:  

• Review of medical history: The healthcare provider will assess overall health and address any medical conditions that could affect treatment. A review of personal and family medical history, including vaccination, is done to identify any conditions that might increase the risk of complications.  
• Physical examination and lab tests: Lab tests, such as pregnancy test, urinalysis, blood panels and liver function tests, may be required. It may include screening for conditions or diseases. A physical examination is also done to confirm their physical readiness for hormone therapy. 
• Behavioral health evaluation: This may be provided to assess gender identity and dysphoria, mental and sexual health, the impact of gender identity on daily life and social interactions, risky behaviors like substance use, and the level of support from family and friends. It also helps in setting treatment goals, managing expectations, and planning care. 
• Getting an informed consent: One must sign an informed consent form, acknowledging their understanding of the treatment’s benefits and possible side effects.

As part of the pre-therapy preparation, healthcare providers will identify and manage tobacco use, drug use, alcohol use disorder, HIV, or other sexually transmitted infections. They will also discuss birth control, fertility, and sexual function. 

Masculinizing hormone therapy usually starts with a low dose of testosterone, which is gradually increased over time. The testosterone used is the same as naturally produced hormones, and synthetic androgens should be avoided due to liver damage risks and monitoring difficulties. 

Some physical changes, like a deeper voice, larger clitoris, and increased body hair, are permanent, while others can be reversed if therapy is stopped. If menstrual bleeding does not stop after several months, additional medication may be needed.

Testosterone is administered through injections, skin gels, or patches, with other options like pellets, long-acting injections, or oral capsules. 

Gradual changes that the body will experience after starting masculinizing hormone therapy include: 

• Menstruation stops within 2 to 6 months.  
• Increased muscle mass and strength, which begins in 6 to 12 months and reaches full effect within 2 to 5 years.  
• Redistribution of body fat, which begins within 3 to 6 months and takes 2 to 5 years for the full effect.  
• A deeper voice, which begins 3 to 12 months after starting and reaches its full effect in 1 to 2 years.  
• Increased facial and body hair growth, starting 3 to 6 months into treatment, with the full effect occurring in 3 to 5 years.  
• Enlargement of the clitoris, along with vaginal lining thinning and dryness, starting 3 to 12 months after treatment and completing within 1 to 2 years.  

Outcome 

While on masculinizing hormone therapy, it is important to be on lookout for some side effects that may signal complications. Seek immediate medical assistance if any of the following symptoms is experienced:  

• Jaundice, or a yellowing of the skin or eyes  
• Dizziness  
• Chest discomfort  
• Trouble urinating  
• Disorders related to sleep, such as apnea  
• Peripheral neuropathy, or tingling in the arms or legs 

Patients should expect to see their healthcare provider every three months during the first year of hormone therapy, and then every six to 12 months thereafter.

Follow-up appointments allow healthcare providers to:  

• Monitor one’s response to treatment and check for complications  
• Monitor physical changes and adjust testosterone dosage as needed 
• Track hormone levels and conducts lab tests to assess cholesterol, potassium, blood sugar, blood count, and liver enzymes. 
• A bone density test (DEXA scan) may be performed 
• Closely monitor behavioral health 

Other preventive measures that may be required include:

• Monitoring bone health: Along with considering calcium and vitamin D supplements, bone health should be monitored with bone density tests based on recommendations for cisgender men of the same age.  
• Breast cancer screening: Based on cisgender women guidelines, breast cancer screening should be done.  
• Cervical cancer screening: One should be aware that masculinizing hormone therapy can thin cervical tissues, which may resemble cervical dysplasia (abnormal cells on the cervix). Cervical cancer screening for transgender men should follow the same guidelines as for cisgender women of the same age.