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.
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You can think of hormones as chemical messengers that regulate the systems in the body.  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.  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.
Estrogen is a sex hormone that most people start producing during puberty. 
Females 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. 
Females naturally produce three types of estrogen, whereas males only produce two. The three types of estrogen are: 
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: 
In men and people assigned male at birth, estrogen helps regulate libido, erectile function, and sperm production. 
Estrogen also has non-reproductive functions. Whether you’re a male, female, or intersex, estrogen can impact your: 
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. 
Estrogen naturally decreases in females as they approach menopause.  Some females may also see a drop in estrogen in response to certain health issues. No matter what the cause is, low estrogen in females is often characterized by: 
In males, low estrogen levels may lead to a lower sex drive, bone loss, and the development of excess abdominal fat. 
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. 
Some potential signs of estrogen dominance in females include: 
Males with estrogen dominance may experience infertility, erectile dysfunction, or gynecomastia (enlargement of the breasts). 
Estrogen dominance can develop naturally in response to insulin resistance, excess stress, or intestinal dysbiosis.  You can also take in too much exogenous estrogen from hormonal contraceptives, hormone replacement therapy, certain foods, or exposure to synthetic xenoestrogens.
Like estrogen, progesterone is a sex hormone that’s found in female, male, and intersex bodies in varying degrees.  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.  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.
Like estrogen, progesterone has both reproductive (sex-specific) and non-reproductive functions.
In females and people assigned female at birth, progesterone can: 
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: 
In males and people assigned male at birth, progesterone plays a role in semen production.  It also serves to combat the development of estrogen dominance.
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. 
Like estrogen, low progesterone can impact menstruation, libido, fertility, and weight management in women. 
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.
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:
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.
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. 
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.
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 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 by a healthcare provider or by taking an at-home health test. Then, depending on the results, they may suggest hormone therapy or hormone replacement options to help you reach a healthy estrogen and/or progesterone level.
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.