How Does Estrogen Affect People Assigned Male at Birth?

If your estrogen levels are low, your brain, bone, heart, and sexual health may be negatively impacted. In cisgender men and others assigned male at birth, estrogen levels can drop for any number of reasons.

You’d be forgiven for thinking estrogen only exists naturally in people assigned female at birth. After all, estrogen is often (confusingly) categorized as the “female” reproductive hormone.

But estrogen is a hormone that everybody naturally has in some quantity. And for the record, testosterone, which is often dubbed the “male” reproductive hormone, is present in all people at some level, too.

There are two main reasons that someone assigned male at birth might take an estrogen supplement, sometimes known as estrogen therapy:

1. You have low estrogen levels and are experiencing unwanted side effects or symptoms as a result.
2. You’re taking estrogen as part of gender-affirming care.

Ahead, read all about the role of estrogen in the body as well as signs that it’s low. Plus, how estrogen therapy impacts and can benefit the gender-expansive individuals who are a good fit for it.

Estrogen is responsible for a number of different bodily functions across the sex and gender spectrum, says Michelle Forcier, MD, a gender-affirming clinician with virtual healthcare service FOLX.

• cognitive function
• bone health
• cardiovascular capacity
• sexual health

If estrogen levels become low, then brain, bone, heart, and sexual health can all be negatively impacted. In people assigned male at birth, estrogen levels can drop for any number of reasons.

• high weight and BMI
• rapid weight loss or undereating
• older age
• high blood pressure
• use of steroid medication
• infections
• pituitary or adrenal gland malfunction or disease
• diabetes
• autoimmune conditions

Whatever the cause, lower estrogen levels in people assigned male at birth can lead to any number of unsavory symptoms and side effects.

• mood irregularities
• reduced libido
• difficulty sleeping or oversleeping
• generalized fatigue
• body temperature dysregulation
• erectile dysfunction

High estrogen levels actually cause a similar set of symptoms in people assigned male at birth. But gynecomastia and infertility are two additional risks.

Symptoms aside, you can get your estrogen levels checked with a simple blood test.

The test will check for the two main types of estrogen — estrone and estradiol — which are measured per milliliter (pg/ml).

On average, people assigned male at birth have the following levels of estrogen at different stages of life:

If your estrogen level is outside of these ranges, a healthcare professional may recommend lifestyle modifications or medications, including low dose estrogen gel or cream, to help get your body back on track.

“Estrogen can also be taken by people assigned male at birth as part of gender affirmative care,” says Forcier.

The goal is to help an individual work toward a physical body that’s more congruent with their experience of gender internally, she says.

In this scenario, Forcier notes that the dosage is typically much higher than what would be used to correct low estrogen levels.

“Estradiol might be taken for a lifetime or a short time,” says Forcier. It ultimately depends on your desired physical change, overall health, age, and more. “Most people who start estradiol want to continue it forever. But, if they do not and want to stop it, they can stop any time.”

To understand how long you’ll need to take it to see, feel, and/or maintain your desired changes, talk with a gender-affirming healthcare professional.

Physical effects

Estrogen — specifically, a type of estrogen called estradiol — suppresses testosterone, reducing its effects on the body, says Forcier.

As a result, you may notice some of the following:

• decreased libido
• erectile dysfunction
• increased chest (breast) tissue
• fat redistribution to hips and chest
• softer skin
• thinning facial and body hair

“Over time, estradiol might impact or reduce fertility since the testes would not be supplied with testosterone like they need to create sperm,” she says.

However, estrogen therapy is *not* the same as a vasectomy. So if your sexual partner(s) could become pregnant, you should use pregnancy prevention tactics unless you’re mutually ready to grow your family.

Mental and emotional effects

“Taking estradiol to affirm your gender identity can have wonderfully important effects on your overall life,” says Forcier.

“Getting affirmative gender care, hormones, and so on can help make an individual more comfortable in their body and gender, which has protective effects against depression, anxiety, and suicidality,” she says.

Given that transgender adults are more likely than their cisgender peers to have symptoms of depression, or to report suicidal ideation or attempts, the improved mental health outcomes can’t be overstated.

If you think you could be a good candidate for estrogen therapy, consult a healthcare professional.

Any of the aforementioned symptoms of low estrogen — or unexpected physical, mental, or emotional changes — are all reasons to make an appointment with a doctor or other healthcare professional.

And if you have questions about gender-affirming care, a primary care doctor can help.

Gabrielle Kassel (she/her) is a queer sex educator and wellness journalist who is committed to helping people feel the best they can in their bodies. In addition to Austra Health, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.

Last medically reviewed on March 10, 2023