Estrogen vs. progesterone: key points to know

Medically reviewed on August 17, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

• What is estrogen?
• What is progesterone?
• Estrogen vs progesterone: Understanding the key differences
• Is estrogen or progesterone better?
• Everlywell: Test your hormone levels at home today

You can think of hormones as chemical messengers that regulate the systems in the body. [1] They send signals to those systems to tell them when it’s time to get a move on, coordinating all sorts of changes and effects. As a human, you have over 50 different hormones—and two of these hormones are estrogen and progesterone.

Estrogen and progesterone are best known for their effect on the sexual development of women and people assigned female at birth. However, these hormones also impact many other systems in the body. [2] As a result, men and intersex individuals need some estrogen and progesterone, too.

To understand the roles estrogen and progesterone play within the body, it can help to define these two hormones and break down their differences. We’ll also explore their part in regulating female fertility and menstruation.

What is estrogen?

Estrogen is a sex hormone that most people start producing during puberty. [3]

Those assigned female at birth produce most of their estrogen within their ovaries. Some of their estrogen is also created within the adrenal glands, fat tissue, and brain. During pregnancy, the placenta secretes some estrogen, too. [3]

People with ovaries naturally produce three types of estrogen, whereas people with testicles only produce two. The three types of estrogen are: [3]

• Estradiol – Estradiol is the most potent form of estrogen found in female bodies during their reproductive years. [4] Male bodies also produce some estradiol.
• Estriol – Estriol is the type of estrogen that circulates in females during pregnancy. It is the most abundant type of estrogen found in female bodies, but it’s also the least potent. Male bodies do not produce any estriol.
• Estrone – Estrone is the only form of estrogen produced in female bodies that have entered menopause. Males produce some estrone, too.

What does estrogen do?

The functions of estrogen vary, depending on sex, age, and pregnancy status. In women and people assigned female at birth, estrogen’s primary roles are to: [3]

• Stimulate breast growth and body recomposition during puberty
• Support reproductive organ development
• Halt height development and hinder muscle bulk
• Thicken the uterine lining
• Prepare the uterus for a potential pregnancy

In men and people assigned male at birth, estrogen helps regulate libido, erectile function, and sperm production. [3]

Estrogen also has non-reproductive functions. Regardless of gender identity or biological sex, estrogen can impact your: [3]

• Bone density
• Blood sugar
• Cholesterol levels
• Brain function
• Concentration
• Blood flow and circulation
• Skin collagen
• Skin moisture
• Mood regulation

What happens when estrogen levels are low?

As you can see, estrogen has a wide range of essential functions. For this reason, it’s important to maintain healthy levels of estrogen for your sex and age. If estrogen becomes too low or too high, you can develop certain health issues. [3]

Estrogen naturally decreases in people assigned female at birth as they approach menopause. [3] Some people may also see a drop in estrogen in response to certain health issues. No matter what the cause is, low estrogen in people assigned female at birth is often characterized by: [3]

• Irregular or absent periods
• Hot flashes or night sweats
• Sleeping problems
• Fatigue
• Dry skin
• Vaginal dryness
• Low libido
• Tender breasts
• Brittle bones
• Headaches
• Mood dysregulation

In those assigned male at birth, low estrogen levels may lead to a lower sex drive, bone loss, and the development of excess abdominal fat. [5]

What happens when estrogen levels are high?

While you don’t want estrogen levels to be too low, you don’t want them to become too high, either. If estrogen levels exceed progesterone levels, you may develop a condition known as estrogen dominance. [6]

Some potential signs of estrogen dominance in people assigned female at birth include: [6]

• Irregular periods
• Weight gain
• Bloating
• Low libido
• Fatigue
• Mood swings
• Premenstrual syndrome (PMS)
• Breast tenderness
• Uterine fibroids
• Ovarian tumors
• PCOS
• Fibrocystic breasts
• Endometriosis

Males with estrogen dominance may experience infertility, erectile dysfunction, or gynecomastia (enlargement of the breasts). [6]

What does it mean if estrogen is higher than progesterone?

Estrogen dominance can develop naturally in response to insulin resistance, excess stress, or intestinal dysbiosis. [7] You can also take in too much exogenous estrogen from hormonal contraceptives, hormone replacement therapy, certain foods, or exposure to synthetic xenoestrogens.

What is progesterone?

Like estrogen, progesterone is a sex hormone that’s found in female, male, and intersex bodies in varying degrees. [8] Progesterone is derived from cholesterol.

Females produce most of their progesterone in the corpus luteum, which is a temporary endocrine gland that arises after ovulation. [2] Some female progesterone is also secreted in the ovaries and adrenal glands. During pregnancy, the placenta takes over a portion of progesterone production.

Males produce progesterone in their testes and adrenal glands.

What does progesterone do?

Like estrogen, progesterone has both reproductive (sex-specific) and non-reproductive functions.

Sex-specific

In females and people assigned female at birth, progesterone can: [2]

• Prepare the uterus lining for the potential implantation of a fertilized egg
• Prevent uterine muscle contractions that may otherwise reject the fertilized egg

If a female doesn’t become pregnant after ovulation, the corpus luteum goes away, causing progesterone levels to drop and menstruation to begin.

If a female does become pregnant, progesterone helps to: [2]

• Prevent ovulation throughout pregnancy
• Support the development of the placenta
• Nourish the fetus throughout pregnancy
• Prepare the breasts to produce milk

In males and people assigned male at birth, progesterone plays a role in semen production. [9] It also serves to combat the development of estrogen dominance.

Non-reproductive

In people of all sexes, progesterone can help regulate a variety of systems. Most notably, this hormone can impact brain function, bone health, and the cardiovascular system. [10]

What can happen when progesterone levels are low?

Like estrogen, low progesterone can impact menstruation, libido, fertility, and weight management in women. [11]

Low progesterone may present serious problems when it comes to pregnancy. Since progesterone is crucial for a healthy pregnancy, low levels are associated with an increased risk of miscarriage or premature birth.

In males, low progesterone levels may result in estrogen dominance and the associated symptoms discussed earlier.

Estrogen vs progesterone: Understanding the key differences

As you can see, estrogen and progesterone work together to support healthy reproduction. They also play a role in several other important processes within the body.

Despite their similarities, estrogen and progesterone have some key differences in how they operate within the body. These include the impact they have on:

• The menstrual cycle – When it comes to the menstrual cycle, estrogen and progesterone differ in terms of their timing. [12] Estrogen is higher during the first half of the menstrual cycle, which is known as the follicular phase. This phase takes place during the two weeks leading up to ovulation. Progesterone takes over as the dominant hormone after ovulation and typically peaks one week prior to menstruation. This part of the menstrual cycle is known as the ovulatory phase.
• Fertility – Estrogen or progesterone imbalances can impact fertility in all sexes. In females, estrogen is largely responsible for preparing the female body for potential pregnancy, whereas progesterone is more closely associated with maintaining a pregnancy. [12]
• Cancer risk – Estrogen dominance can cause uterine cells to multiply out of control, potentially leading to the development of cancer. Adequate progesterone levels can counteract some of these effects. [13] However, both types of hormones have been associated with breast cancer. [14]
• Birth control – Some birth control pills contain a combination of estrogen and progestin, which is a synthetic form of progesterone that’s more easily absorbed by the body. Combination birth control pills work by preventing ovulation from occurring. [15] Other birth control pills contain only progestin. Progestin-only pills work by thickening the uterus’ mucus to the point in which sperm can’t reach the egg.

Is estrogen or progesterone better?

Estrogen and progesterone are both equally important for the healthy functions of the body. If they’re at proper levels, these two hormones can support your optimal health and wellbeing.

The only time this question may be relevant is in regards to hormonal contraception. For some people, hormonal contraceptives with both estrogen and progestin may work better. But others may prefer to take a progestin-only pill.

Are combination pills or progestin-only pills better?

All hormonal contraceptives may cause some side effects. For instance, combination pills may be more likely to cause headaches, nausea, libido disruptions, breast tenderness, abdominal cramping, and blood clots. In contrast, progestin-only pills may be more likely to cause follicular ovarian cysts and acne. [16]

Both types of birth control pills can cause breakthrough bleeding, especially during the first few months of a new birth control prescription.

You can ask your healthcare provider which type of birth control is better suited for you based on your unique health factors and family history.

Do I need progesterone and estrogen?

By now, it should be clear that everyone needs a certain amount of progesterone and estrogen in their bodies—females, males, and intersex people alike.

But what if you experience a hormone imbalance? If if you’re concerned that your estrogen or progesterone levels aren’t where they should be, you have options. You can have your hormone levels checked at a healthcare provider or by taking an at-home health test. This is a crucial step if you want to learn how to increase estrogen naturally. Then, they can suggest hormone therapy or hormone replacement options to help you reach a healthy estrogen and progesterone level.

Everlywell: Test your hormone levels at home today

Are you curious about your hormone levels or how to test estrogen levels at home? If you’re experiencing menstrual irregularity, issues becoming pregnant, or any of the other symptoms we discussed above, you may want to have your hormone levels checked.

At Everlywell, we offer an easy at-home Women's Fertility Test. This test checks five key fertility hormones, including estradiol, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, and total testosterone. Once you send in your blood sample (collected with an easy finger prick), we test it at one of our CLIA-certified labs and have one of our independent board-certified physicians review your results.

Are you ready to gain insight into your hormonal health? Order your Everlywell Women’s Fertility Test today.

Related content

How to Test Estrogen Levels at Home

Can Stress Cause Ovarian Cysts?

What is a Follicle on the Ovary?

Benefits of Progesterone After Menopause

References

1. Cleveland Clinic. Hormones. URL. Accessed August 17, 2022.
2. Endocrine Society. Reproductive Hormones. URL. Accessed August 17, 2022.
3. Cleveland Clinic. Estrogen. URL. Accessed August 17, 2022.
4. NIH. Estradiol. URL. Accessed August 17, 2022.
5. Cleveland Clinic. Low Estrogen. URL. Accessed August 17, 2022.
6. Cleveland Clinic. High Estrogen. URL. Accessed August 17, 2022.
7. U.S. Department of Veterans Affairs. Estrogen Dominance. URL. Accessed August 17, 2022.
8. NIH. Physiology, Progesterone. URL. Accessed August 17, 2022.
9. NIH. Progesterone: the forgotten hormone in men? URL. Accessed August 17, 2022.
10. Frontiers. Non-genomic mechanisms of progesterone action in the brain. URL. Accessed August 17, 2022.
11. NIH. Serum progesterone distribution in normal pregnancies compared to pregnancies complicated by threatened miscarriage from 5 to 13 weeks gestation: a prospective cohort study. URL. Accessed August 17, 2022.
12. NIH. The Normal Menstrual Cycle and the Control of Ovulation. URL. Accessed August 17, 2022.
13. Cleveland Clinic. Estrogen-Dependent Cancers. URL. Accessed August 17, 2022.
14. JAMA Network. Progesterone Exposure and Breast Cancer Risk—Addressing Barriers. URL. Accessed August 17, 2022.
15. MedlinePlus. Birth control pills. URL. Accessed August 17, 2022.
16. NIH. Oral Contraceptive Pills. URL. Accessed August 17, 2022.