Masculinizing hormone therapy is used to induce the physical changes in your body caused by male hormones during puberty (secondary sex characteristics) to promote the matching of your gender identity and body (gender congruence). If masculinizing hormone therapy is started before the changes of female puberty begins, female secondary sex characteristics, such as the development of breasts, can be avoided. Masculinizing hormone therapy is also referred to as cross-sex hormone therapy.
During masculinizing hormone therapy, you'll be given the male hormone testosterone, which suppresses your menstrual cycles and decreases the production of estrogen from your ovaries. Changes caused by these medications can be temporary or permanent. Masculinizing hormone therapy can be done alone on in combination with masculinizing surgery.
Masculinizing hormone therapy isn't for all transgender men, however. Masculinizing hormone therapy can affect your fertility and sexual function and cause other health problems. Your doctor can help you weigh the risks and benefits.
Why it's done
Masculinizing hormone therapy is used to alter your hormone levels to match your gender identity.
Typically, people who seek masculinizing hormone therapy experience distress due to a difference between experienced or expressed gender and sex assigned at birth (gender dysphoria). To avoid excess risk, the goal is to maintain hormone levels in the normal range for the target gender.
Masculinizing hormone therapy can:
- Make gender dysphoria less severe
- Reduce psychological and emotional distress
- Improve psychological and social functioning
- Improve sexual satisfaction
- Improve quality of life
Although use of hormones is currently not approved by the Food and Drug Administration for treatment of gender dysphoria, research suggests that it can be safe and effective.
If used in an adolescent, hormone therapy typically begins at age 16. Ideally, treatment starts before the development of secondary sex characteristics so that teens can go through puberty as their identified gender. Hormone therapy is not typically used in children.
Masculinizing hormone therapy isn't for everyone, however. Your doctor might discourage masculinizing hormone therapy if you:
- Had or have a hormone-sensitive cancer, such as breast cancer
- Have a thromboembolic disease, such as when a blood clot forms in one or more of the deep veins of your body (deep vein thrombosis) or a blockage in one of the pulmonary arteries in your lungs (pulmonary embolism)
- Are pregnant
- Have uncontrolled significant mental health issues
Talk to your doctor about the changes in your body and any concerns you might have. Complications of masculinizing hormone therapy include:
- Producing too many red blood cells (polycythemia)
- Weight gain
- Developing male-pattern baldness
- Sleep apnea
- Elevated liver function tests
- An abnormal amount of lipids in the blood (dyslipidemia), with a higher risk in those who have polycystic ovary syndrome
- Worsening of an underlying manic or psychotic condition
- High blood pressure (hypertension), type 2 diabetes and cardiovascular disease, when risk factors are present
Evidence suggests no increased risk of breast or cervical cancer.
The evidence that masculinizing hormone therapy increases the risk of ovarian and uterine cancer is inconclusive. Further research is needed.
Because masculinizing hormone therapy might reduce your fertility, you'll need to make decisions about your fertility before starting treatment. The risk of permanent infertility increases with long-term use of hormones, especially when hormone therapy is initiated before puberty. Even after discontinuation of hormone therapy, ovarian and uterine function might not recover well enough to ensure that you can become pregnant.
If you want to have biological children, talk to your doctor about egg freezing (mature oocyte cryopreservation) or embryo freezing (embryo cryopreservation). Keep in mind that egg freezing has multiple steps — ovulation induction, egg retrieval and freezing. If you want to freeze embryos, you'll need to go through the additional step of having your eggs fertilized before they are frozen.
At the same time, while testosterone might limit your fertility, you're still at risk of pregnancy if you have your uterus and ovaries. If you want to avoid becoming pregnant, use a barrier form of contraception or an intrauterine device.
How you prepare
Before starting masculinizing hormone therapy, your doctor will evaluate your health to rule out or address any medical conditions that might affect or contraindicate treatment. The evaluation might include:
- A review of your personal and family medical history
- A physical exam, including an assessment of your external reproductive organs
- Lab tests measuring your lipids, blood sugar, blood count, liver enzymes and electrolytes, and a pregnancy test
- A review of your immunizations
- Age- and sex-appropriate screenings
- Identification and management of tobacco use, drug abuse, alcohol abuse, HIV and other sexually transmitted infections
- Discussion about contraception and your desire for future fertility
- Discussion about use of potentially harmful treatment approaches, such as unprescribed hormones or industrial-strength silicone injections
You might also need a mental health evaluation by a provider with expertise in transgender health. The evaluation might assess:
- Your gender identity and dysphoria
- The impact of your gender identity at work, school, home and social environments, including issues related to discrimination, relationship abuse and minority stress
- Mood or other mental health concerns
- Sexual health concerns
- Risk-taking behaviors, including substance use and use of nonmedical-grade silicon injections or unapproved hormone therapy or supplements
- Protective factors such as social support from family, friends and peers
- Your goals, risks and expectations of treatment and your future care plans
Adolescents younger than age 18, accompanied by their custodial parents or guardians, also should see doctors and mental health providers with expertise in pediatric transgender health to discuss the risks of hormone therapy, as well as the effects and possible complications of gender transition.
What you can expect
During the procedure
Typically, you'll begin masculinizing hormone therapy by taking testosterone. Testosterone is given either by injection or by a patch or gel applied to the skin. Oral testosterone or synthetic male sex hormone (androgen) medication shouldn't be used because of potential adverse effects on your liver and lipids.
If you have persistent menstrual flow, your doctor might recommend taking progesterone to control it.
After the procedure
Masculinizing hormone therapy will begin producing changes in your body within weeks to months. Your timeline might look as follows:
- Oily skin and acne. This will begin one to six months after treatment. The maximum effect will occur within one to two years.
- Cessation of your period. This will occur within two to six months of treatment.
- Voice deepens. This will begin three to 12 months after treatment. The maximum effect will occur within one to two years.
- Facial and body hair growth. This will begin three to six months after treatment. The maximum effect will occur within three to five years.
- Body fat redistribution. This will begin within three to six months. The maximum effect will occur within two to five years.
- Clitoral enlargement and vaginal atrophy. This will begin three to six months after treatment. The maximum effect will occur within one to two years.
- Increased muscle mass and strength. This will begin within six to 12 months after treatment. The maximum effect will occur within two to five years.
- Scalp hair loss. This will occur within 12 months of treatment.
After masculinizing hormone therapy, you'll meet regularly with your doctor. He or she will:
- Document your physical changes
- Monitor your hormone concentration, and use the lowest dose necessary to achieve desired physical effects
- Monitor changes in your lipids, fasting blood sugar, blood count, liver enzymes and electrolytes that could be caused by hormone therapy
- Monitor your mental health stability
After masculinizing hormone therapy, you will also need routine preventive care if you have not had certain surgical interventions, including:
- Breast cancer screening based on age-appropriate female screening recommendations
- Cervical cancer screening based on age-appropriate recommendations
- Early evaluation of persistent or recurrent vaginal bleeding
- Evaluation for obstructive sleep apnea
When undergoing cervical cancer screening, be sure to share that you're on testosterone therapy and make sure that the gender designation on your sample is disregarded. This kind of therapy can cause your cervical tissues to thin (cervical atrophy), which might mimic a condition in which abnormal cells are found on the surface of the cervix (cervical dysplasia).