Everything You Need to Know Before Starting Hormone Therapy

Gender-Affirming Hormone Therapy (GAHT) is a medical treatment that helps some transgender, non-binary, and gender-diverse individuals develop physical characteristics that are more closely aligned with their gender identity.

For many people, GAHT plays an important role in reducing gender dysphoria and improving psychological well-being and overall quality of life. Like any medical treatment, however, it has potential benefits, limitations, and risks that should be carefully considered before making a decision.

This guide summarizes the key information you should know based on current clinical guidelines to help you make an informed decision.

What Is Gender-Affirming Hormone Therapy?

GAHT works by changing hormone levels in the body to encourage the development of certain physical characteristics while reducing the effects of others.

Treatment is highly individualized. Two people with the same gender identity may have completely different goals. Some individuals seek more extensive physical changes, while others may only want specific changes.

The goal is not to achieve an "ideal" appearance, but rather to develop a treatment plan that aligns with each person's individual goals, values, and expectations.

How Do Hormones Affect the Body?

The human body naturally produces several sex hormones, primarily estrogen, testosterone, and progesterone. These hormones influence physical development during puberty and continue to affect many body systems throughout life.

Gender-affirming hormone therapy changes the body's hormonal balance to promote desired physical characteristics while reducing the influence of other hormones.

For example:

• Estrogen promotes breast development and body fat redistribution.
• Testosterone promotes facial hair growth, deepening of the voice, and increased muscle mass.
  
  

What Types of Hormone Therapy Are Available?

Feminizing Hormone Therapy

Feminizing hormone therapy aims to promote the effects of estrogen while reducing the effects of testosterone when appropriate.

Depending on your individual needs, treatment may include:

• Estrogen
• Anti-androgen medication (to reduce the effects of testosterone)
• In selected situations, progesterone

Treatment plans are individualized based on each person's goals and medical history.

L'hormonothérapie masculinisante

Masculinizing hormone therapy uses testosterone to promote masculine physical characteristics.

Testosterone may be administered in different forms, including injections or topical gels, depending on personal preference and clinical considerations.

What Changes Can I Expect?

The effects of hormone therapy develop gradually.

Some changes begin within weeks or months, while others continue to develop over several years.

The rate of change depends on many factors, including:

• Hormone dosage
• Age
• Genetics
• Overall health
• Individual response to treatment

Everyone responds differently, and your experience will be unique.

Common Physical Changes

Feminizing Hormone Therapy

Possible changes include:

• Gradual breast development
• Reduced muscle mass
• Redistribution of body fat toward the hips and thighs
• Reduced libido in some individuals
• Decreased body hair (often limited without additional hair removal treatments)
• Softer, thinner skin
• Reduced sperm production

It is important to know that estrogen generally does not change a voice that has already deepened during puberty.

Masculinizing Hormone Therapy

Possible changes include:

• A deeper voice
• Facial hair growth
• Increased body hair
• Increased muscle mass
• Oilier skin
• Acne, especially during the first months of treatment
• Cessation of menstrual periods in most individuals
• Enlargement of the clitoris (clitoral growth)
• Increased libido in some individuals

Which Changes Are Permanent?

Not all physical changes are permanent. Which changes are generally reversible? 

Increased muscle mass? Yes, mostly

Body fat redistribution? Yes, mostly

Reduced fertility? Variable

Breast development? Partiellement

Voice deepening? No

Facial hair growth? Little or no reversal

Clitoral growth? No

The degree of reversibility depends on factors such as treatment duration, hormone dosage, and individual response.

How Long Does It Take to See Results?

Timelines vary considerably from person to person.

In general:

• Some changes begin within weeks or months.
• Many changes continue to develop over 2 to 5 years.
• Some changes reach their maximum effect sooner than others.

It is important to have realistic expectations and understand that GAHT is a gradual process.

Can Hormone Therapy Affect Fertility?

Yes.

Depending on the treatment used, fertility may decrease temporarily or permanently.

If you think you may want biological children in the future, it is recommended to discuss fertility preservation options—such as sperm banking or egg freezing—before starting hormone therapy.

It is also important to know that pregnancy may still be possible for some individuals depending on the reproductive organs present. Birth control may therefore still be necessary.

What Are the Risks?

Like any medical treatment, GAHT has potential risks.

These vary depending on the medications used, dosage, medical history, and individual risk factors.

Your healthcare provider will assess factors such as:

• Personal and family history of cardiovascular disease
• Risk of blood clots
• High blood pressure
• Diabetes
• Cholesterol levels
• Liver disease
• Smoking
• Other medical conditions that may influence treatment choices

Regular medical follow-up helps optimize treatment while minimizing potential risks.

Why Are Blood Tests Necessary?

Laboratory testing helps ensure that hormone therapy remains both safe and effective.

Depending on your situation, blood tests may be used to:

• Measure hormone levels
• Monitor hemoglobin and hematocrit
• Assess liver function
• Evaluate kidney function
• Monitor electrolytes
• Follow other laboratory values relevant to your individual care

The tests ordered will vary from person to person.

Do I Need to See a Psychologist Before Starting Hormone Therapy?

Not necessarily.

Current international guidelines do not require psychotherapy before starting Gender-Affirming Hormone Therapy.

However, some people find psychological support helpful for exploring their gender identity, navigating different stages of their journey, or receiving emotional support.

Depending on your individual circumstances, your healthcare provider may recommend additional assessment or psychological support when clinically appropriate.

What Is Informed Consent?

Informed consent is a fundamental part of gender-affirming healthcare.

It is an ongoing discussion between you and your healthcare provider to ensure you understand:

• The expected benefits
• Possible side effects
• Potential risks
• Limitations of treatment
• Alternative options
• Possible effects on fertility

The goal is to help you make a decision that reflects your own values, goals, and preferences.

Myths and Facts

Myth: Hormones completely change your personality.

Fact: Hormones do not change who you are. Some people experience emotional changes related to the adjustment process or improved well-being, but hormone therapy does not alter your personality.

Myth: Everyone must see a psychologist before starting hormone therapy.

Fact: Current guidelines support an individualized approach. Psychological support may benefit some individuals but is not routinely required.

Myth: Hormone therapy always causes permanent infertility.

Fact: GAHT can affect fertility, but the extent and reversibility vary from person to person. This is why discussing fertility preservation before treatment is strongly recommended.

Myth: Higher doses produce better or faster results.

Fact: Higher doses do not necessarily produce faster or greater physical changes and may increase the risk of side effects. The goal is to use the safest and most appropriate dose for your individual treatment goals.

Key Takeaways

Gender-Affirming Hormone Therapy is a personalized medical treatment that can play an important role in improving the well-being and quality of life of many transgender, non-binary, and gender-diverse individuals.

Every journey is unique. Treatment goals, expected outcomes, benefits, and potential risks should be discussed with a qualified healthcare professional to develop a care plan tailored to your individual needs.

References

This guide is based on current evidence and internationally recognized clinical guidelines, including:

• World Professional Association for Transgender Health (WPATH) – Standards of Care for the Health of Transgender and Gender Diverse People, Version 8 (SOC8)
• Endocrine Society – Clinical Practice Guideline: Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons
• Canadian Professional Association for Transgender Health (CPATH)
• Rainbow Health Ontario – Clinical Practice Guidelines for Gender-Affirming Care