Estrogen-Based Hormone Therapy

Some trans and gender diverse people benefit from gender-affirming hormone therapy to promote physical characteristics reflective of one’s gender identity or gender expression.

Estrogen, often in combination with a testosterone blocking medication, is used to reduce testosterone-related features, induce estrogen-related features and relieve distress related to gender. This page sets out the advantages and disadvantages, expected effects, and potential risks of common estrogen, testosterone blocker and progesterone therapies. The list of therapies is not exhaustive. Talk to your health care provider to determine the best fit for you.

Common therapies

Your health care provider will help you tailor your hormone therapy to meet your goals, health needs and budget. Your hormone therapy may include any of the following:

estrogen alone
estrogen and testosterone blockers
estrogen and testosterone blockers and progesterone
testosterone blockers alone (this is not safe for long periods of time)

Common estrogen therapies

Oral estrogen

brand name: Estrace
description: a pill you swallow or dissolve under your tongue each day
advantages: less expensive (around $14 a month)
disadvantages: higher cardiovascular risk for people over 40, especially with other risk factors

Estrogen patch

brand names: Estradot, Estraderm, Oesclim
description: a patch you wear on your skin that gets changed twice a week
advantages: lower cardiovascular risk for people over 40, especially with other risk factors
disadvantages: more expensive (around $25 a month). some people have a skin reaction to the adhesive in the patch

Injectable estrogen (estradiol valerate)

description: a substance you inject every week or two (sometimes twice weekly)
advantages: possibly lower cardiovascular risk for people over 40, especially with other risk factors
disadvantages: requires a compounding pharmacy, more expensive and less widely available, some people find injections to be painful.

Common testosterone blocker therapies

Spironolactone

brand name: Aldactone
description: a pill that you swallow once or twice a day
advantages: most common because it’s less expensive ($22 a month) and usually well tolerated
disadvantages: some people find pills hard to swallow. may make you have to pee more often and may require dietary restrictions

Cyproterone

brand name: Androcur
description: a pill that you swallow once a day
advantages: potent testosterone blocker
disadvantages: more expensive (around $50 a month). may cause liver inflammation, especially in higher doses, and depression

Finasteride

brand name: Proscar
description: a pill that you put under your tongue once a day or every other day. Will not suppress testosterone levels on its own
advantages: can help slow hereditary hair loss
disadvantages: costs around $60 a month

Common progesterone therapies

The role of progesterone is not well understood. Most guidelines do not recommend the use of it as part of a standard regimen but discuss the possibility of using it as an adjunctive medication for a period of time.

Benefits may include positive effects on the development of the nipple and areola and improved libido, but this is unproven.

Common side effects include weight gain, edema, lipid changes and depression. Taking progesterone along with estrogen as compared to taking estrogen alone may increase health risks.

Medroxyprogesterone

brand name: Provera
description: a pill you take daily
advantages: widely available and less expensive
disadvantages: thought to be higher risk

Micronized progesterone

brand name: Prometrium
description: a pill you take daily
advantages: thought to be lower risk than medroxyprogesterone
disadvantages: more expensive at about $90 a month

These therapies are also known as feminizing hormones. To be more inclusive of diverse gender identities, we are using language that focuses on anatomy, treatments and presenting concerns, rather than gender.

Effects

Expected effects of estrogen-based hormone therapies

Breast development

usually starts in 3 to 6 months
breasts reach full size in 2 to 3 years
size varies; A or B cup size is typical
a permanent change

Body fat redistribution

usually starts in 3 to 6 months
reaches maximum effect in 2 to 5 years
less fat on abdomen
more fat on buttocks, hips and thighs
not a permanent change if you stop taking hormones

Reduced muscle mass & strength

usually starts in 3 to 6 months
reaches maximum effect in 1 to 2 years
reduced muscle and strength in upper body
not a permanent change if you stop taking hormones

Softening of skin

usually starts in 3 to 6 months
skin will be softer and less oily
not a permanent change if you stop taking hormones

Less facial & body hair

usually starts in 6 to 12 months
maximum effect in more than 3 years
body hair will appear less noticeable
body hair will grow more slowly
facial hair may grow more slowly and appear less noticeable, but will not go away
if you have scalp hair loss, it may slow down
hair that has already been lost likely will not grow back
not a permanent change if you stop taking hormones

Reduced sex drive

usually starts in 1 to 3 months
reaches maximum effect in 1 to 2 years
less spontaneous physical arousal
not a permanent change if you stop taking hormones

Fertility

timeline varies
sperm may no longer reach maturity
won’t produce as much semen
may not be able to get hard enough for penetrative sex
may become permanently unable to make someone pregnant (but birth control is still recommended)

Smaller gonads (testes)

usually starts in 3 to 6 months
maximum effect in 2 to 3 years
may shrink down to half their initial size
may or may not be a permanent change if you stop taking hormones

Emotional changes

overall emotional state may or may not change; this varies from person to person
may experience a narrower or wider range of emotions or feelings

External video resource

A presentation by Dr. Maddie Deutsch, from the Center of Excellence for Transgender Health.

Introduction to Male-to-Female Hormone Therapy

Risks

Risks associated with estrogen-based hormone therapies

With estrogen-based hormone therapies, there is:

a likely increased risk of serious blood clots (venous thromboembolic disease), gallstones, elevated liver enzymes, weight gain and hypertriglyceridemia (risk factor for heart disease and pancreas problems)
a likely increased risk (with presence of additional risk factors) of cardiovascular disease
a possible increased risk of high blood pressure (hypertension), hyperprolactinemia or prolactinoma
a possible increased risk (with presence of additional risk factors) of type 2 diabetes

There is either no increased risk of breast cancer or the research is inconclusive.

Mood changes are variable; they may be positive or negative, or may have an adjustment period. Many people experience positive mood changes after starting hormone therapy. Any mood changes that cause you concern should be discussed with your primary care provider.

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