Estrogen-based hormones

What are estrogen-based therapies?

A note about language

Estrogen-based 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.

Estrogen-based therapies include estrogen, testosterone blockers and progesterone.

Estrogen is a hormone that is used to induce secondary sex characteristics like breast growth, rounder hips and softer skin. It also reduces testosterone-related features, such as facial hair.
Testosterone blockers reduce natural testosterone production and its effects (such as promoting muscle mass).
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 additional medication for a period of time.

This page describes the advantages, disadvantages, expected effects and potential risks of these therapies. The list of therapies is not exhaustive. Talk to your health care provider to determine the best fit for you.

Different estrogen-therapy combinations

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	Estrogen patch	Injectable estrogen
Brand	Estrace	Estradot, Estraderm, Oesclim	estradiol valerate
Description	A pill you swallow or dissolve under your tongue each day	A patch you wear on your skin that gets changed twice a week	A substance you inject every week or two (sometimes twice weekly)
Advantages	Less expensive (approximately $20–$40 per month)	Lower cardiovascular risk for people over 40, especially with other risk factors	Possibly lower cardiovascular risk for people over 40, especially with other risk factors
Disadvantages	Higher cardiovascular risk for people over 40, especially with other risk factors	More expensive ($35–$50 per month); some people have a skin reaction to the adhesive in the patch	Requires a compounding pharmacy; more expensive and less widely available; some people find injections to be painful; no public options to cover the costs of injectable estrogen.

Common testosterone blocker therapies

	Spironolactone	Cyproterone	Finasteride
Brand	Aldactone	Androcur	Proscar
Description	A pill that you swallow once or twice a day	A pill that you swallow once a day	A pill that you put under your tongue once a day or every other day; will not suppress testosterone levels on its own
Advantages	Most common because it’s less expensive ($20–$40 per month) and usually well tolerate	Potent testosterone blocker	Can help slow scalp hair loss
Disadvantages	Some people find pills hard to swallow; may make you have to pee more often; may require dietary restrictions	More expensive ($32–$100 per month); may cause liver inflammation (especially in higher doses) and depression.	More expensive (approximately $60 per month)

Common progesterone therapies

The role of progesterone in estrogen-based therapy is not well understood. Benefits may include positive effects on the development of the nipple and areola and improved libido, but this is unproven.

Side effects may include weight gain, swelling and depression. Taking progesterone along with estrogen may increase health risks in comparison to taking estrogen alone.

	Medroxyprogesterone	Micronized progesterone
Brand	Provera	Prometrium
Description	A pill you take daily	A pill you take daily
Advantages	Widely available and less expensive	Thought to be lower risk than medroxyprogesterone
Disadvantages	Thought to be higher risk compared with micronized progesterone	More expensive (about $90 a month)

Expected effects of estrogen-based hormone therapies

Increasing breast development

Usually starts 3–6 months after beginning therapy
Breasts reach full size in 2–5 years
Size varies; A or B cup size is typical
A permanent change

Redistributing body fat

Usually starts 3–6 months after beginning therapy
Reaches maximum effect in 2–5 years
Less fat on abdomen
More fat on buttocks, hips and thighs
Not a permanent change

Reducing muscle mass and strength

Usually starts 3–6 months after beginning therapy
Reaches maximum effect in 1–2 years
Reduced muscle and strength in upper body
Not a permanent change

Softening of the skin

Usually starts 3–6 months after beginning therapy
Skin will be softer and less oily
Not a permanent change

Thinning of facial and body hair

Usually starts 6–12 months after beginning therapy
Maximum effect in more than 3 years
Body hair may appear less noticeable
Body hair will grow more slowly
Facial hair may grow more slowly, become thinner 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 sexual response

Usually starts 1–3 months after beginning therapy
Timing of maximum effect varies from person to person
Less spontaneous physical arousal (erections)
Not a permanent change if you stop taking hormones

Fertility

Timeline varies
Sperm may no longer reach maturity
Orgasmic fluid (ejaculate) production is reduced or may go away entirely
May not be able to get erection firm enough for penetrative sex
May become permanently unable to contribute to a pregnancy (but birth control is still recommended since this will not be the case for everyone)

Smaller erogenous tissue (penis) & gonads (testes)

Usually starts 3–6 months after therapy begins
Timing of maximum effect varies from person to person
Erogenous tissue may become smaller
Gonads shrink down to half their initial size
May or may not be a permanent change

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
Not a permanent change

Risks associated with estrogen-based hormone therapies

Estrogen is known to increase the risk of blood clots and gallstones. Estrogen-based treatment may also affect your cardiovascular risk by causing changes to cholesterol, blood pressure, blood sugar and weight. There are other potential risks, depending on the specific medication you use, and you should discuss them with your provider.

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 provider.