Dr. Jennifer Luis ND

What Is The Difference Between Estrogen and Progesterone?

balance showing estrogen on one side and progesterone on the other

The sex hormones estrogen and progesterone are produced in all humans but are more dominant in women than men. The endocrine system is a complicated web of hormonal interactions leading to many characteristics vital to life. Physical characteristics that define genders, mental-emotional responses such as mood, confidence, libido and even energy can be hormone-derived. Estrogen, progesterone, testosterone, DHEA, thyroid and cortisol hormones are made in the ovaries, testis, adrenals, thyroid and the brain in order to direct organs and tissues to function and maintain life. This complexity defines all stages of life from newborns to the elderly.

Estrogen and progesterone work synergistically in women to maintain the menstrual cycle and enable pregnancy amongst other roles. When either are deficient or in excess, imbalance results and symptoms can range such as mood swings, acne, heavy and irregular periods, hair loss, insomnia, anxiety, skin quality deterioration, infertility, weight gain, bloating, headaches and fatigue.

One of the important roles of estrogen is to promote eggs in the ovaries to develop into their mature stages in order to be released during ovulation. Progesterone prepares the uterus for implantation of a fertilized egg and sustains pregnancy. However, outside of fertility, these hormones together help create a balanced mood, maintain healthy skin and sex organs and promote natural processes such as sleep, energy, healthy bones and heart.

What Are Estrogen and Progesterone?

Hormones are the chemical messengers of the body which are created in specific organs and travel throughout the body to initiate or maintain important processes within tissues. Estrogen and progesterone hormones are made in the ovaries primarily and are required for regular menstrual cycles and the ability to become pregnant.

Estrogen and Its Role In the Body

Men and women both produce estrogen, yet in women there are higher amounts of the hormone and more receptors for the cells to bind estrogen. Men make estrogen in the testis, adrenal glands and the brains primarily. Women produce the largest amount of estrogen in the ovaries, but adrenal glands also support levels, especially after menopause.

Considered a growth hormone, estrogen is responsible for female sex characteristics such as breast development, menstrual cycles and ability to become pregnant. This important hormone does much more including preventing osteoporosis and protecting blood vessels and the heart against inflammation and heart disease.

Estrogen levels are typically higher than progesterone during the initial half of the menstrual cycle, which includes the first day of menstruation, up until mid-cycle or ovulation correlating to Days 1-13 of a typical cycle. This is the follicular phase and is the time when an egg matures in the ovary before being released and potentially fertilizing. Estrogen levels rise and fall at two times during a typical cycle and this pattern repeats in non-pregnant women.

The Effects of Estrogen Levels In the Body

There are 3 important forms of progesterone, each play a role and have unique characteristics. Estrone (E1), estradiol (E2) and estriol (E3) can interconvert and change proportionally throughout a woman’s life. Estradiol is the primary estrogen and when it lowers during menopause, symptoms such as heat, insomnia, brain fog, low mood and changes to skin quality become apparent. 

Estriol and estrone are made from estradiol and are considered weaker forms. Estriol is highest during pregnancy yet often tends to be the first form to fall with menopausal changes. It is protective for bones and helps to maintain healthy vaginal tissue along with strengthening bladder control. Vaginal application of estriol can be prescribed to women with vaginal dryness and weak bladder control during menopausal years.

Estrone is mainly synthesized from estradiol in the glands and liver and levels rise as a woman ages. It is considered the weakest form yet when imbalanced irregular periods, low energy and mood changes can occur. After menopause, estrone is the main form that continues to be produced and it can be converted into estradiol as needed. This form breaks down into both protective and high risk sub-types of estrogen. Genetics and obesity can increase the amount of estrone and elevation can lead to a higher risk of breast cancer. Advanced urine testing can provide insight into levels of E1, E2 and E3 along with progesterone levels and the other sex and metabolic hormones.

High Estrogen Levels

Elevated levels of estrogen, also known as estrogen dominance, can lead to symptoms such as hormonal headaches or migraines, heavy periods, shorter and more painful cycles, PMS and mood swings. Many women will experience higher baseline estrogen when heading into peri-menopause, and it is not uncommon for elevated levels to contribute to uterine fibroid and ovarian cyst development.

One approach to elevated estrogen levels is assisting the body to excrete estrogen more efficiently. This means increasing fibre intake, ensuring constipation is treated and aiding bile production along with liver detox. This can be achieved with individualized protocols using herbs and other nutrients prescribe by a naturopathic physician.

Another way to balance out elevated estrogen is to promote progesterone levels. The balance between estrogen and progesterone especially in the luteal phase is important. Herbs and bio-identical progesterone provide support to off-set symptoms related to elevated estrogen.

Low Estrogen Levels

Low estrogen levels can be a normal process when women approach peri-menopause and menopause. In younger women, this can contribute to difficulties getting pregnant. Estrogen levels can be improved using healthy nutrition, exercise, herbs, supplements and bio-identical hormone replacement depending on the situation and symptoms.

Bio-identical estrogen, otherwise known as Bi-est, is composed of estradiol and estriol. It is a topical prescription that is typically applied to the skin or vagina in menopausal women. Bi-est can be custom made with proportions of E2 and E3 that match hormone optimization based on labs and symptoms. Estrone should not be used in therapy typically as it will metabolize into byproducts that can create a higher estrogen-associated risks. 

In some cases, estriol alone can be prescribed as a vaginal application. E3 helps to support vaginal tissue resulting in less dryness, atrophy and structurally maintains tissue surrounding the bladder. This can help with urine leakage and incontinence.

Progesterone and Its Role In the Body

Progesterone is more dominant in the second half of the cycle, the luteal phase. the LH spike at ovulation signifies the start to increasing levels and uterine lining will begin to grow in preparation for the fertilized egg implantation. If no pregnancy occurs, progesterone levels drop and menstruation begins.

Aside for the technical menstrual cycle roles the progesterone plays, it is a hormone that balances mood. Deficiencies in progesterone can leave women with anxiety, strong mood swings, irritability and depression. These emotional changes are often seen at elevated levels leading up to menstruation. Since progesterone is often the first hormone to start declining with age, women can feel mood imbalances come on or worsen over time.

High Progesterone Levels

While not common, some women can test high for progesterone levels. If on hormone therapy, this can signify over-prescribing and a dose alteration may be required. Sometimes progesterone is elevated due to difficulties clearing it out of the body as opposed to over production. Taking a look at digestion, fibre intake and bile production may help to balance progesterone to optimal levels.

Women using progesterone therapy might note puffy faces, water retention, bloating and tender breasts if their prescription is too high. In rare cases, excess progesterone may enhance mood swings or anxiety.

Low Progesterone Levels

Low progesterone is a common finding on hormone tests. In younger women, this can be as a result of stress. Pregnenalone is a hormone that converts into both cortisol and progesterone. When stress is high, the stress hormone cortisol is put into overdrive production and pregnenalone will preferentially convert into cortisol and less into progesterone. Working on lowering stress with improvements to sleep habits, stress management, healthy diet and supplementation can make significant improvements to progesterone levels in this scenario.

Peri-menopause is often when natural progesterone levels start to decline. This might also be the time when cycle and mood changes are noted and causing unwanted effects. Treatment can vary with both herbs and natural progesterone prescriptions yielding successful management of symptoms.

Natural progesterone can be prescribed as a topical cream, vaginal suppository or an oral pill form. Depending on the desired affects, both forms are are common and safe. Oral progesterone can promote better sleep and is typically the preferred form for peri-menopause and menopause. Progesterone can be safely used while still menstruating and does not require estrogen to be used at the same time.

Estrogen vs Progesterone: Fertility Effects

The harmony of estrogen and progesterone is vital to a regular menstrual cycle. Rises and falls of both hormones cause egg maturation and release (ovulation) as well as uterine lining preparation and shedding. Appropriate hormone production at optimal times during the cycle will help with fertility and successful pregnancies. Optimizing the natural menstrual cycle can be done when a thorough hormone evaluation is completed. Multiple ways to test hormones are available, some types are quite specialized and can be ordered through naturopathic doctors.

Testing Your Estrogen and Progesterone Levels

There are multiple ways to test sex hormones. Blood, urine and saliva levels will give different information and depending on what is desired to know, each have their benefits.

Blood (serum) levels of hormones when taken at particular times of the cycle can provide insight regarding fertility and optimal cycling. Usually performed on specific days of the cycle, the absolute levels of estradiol and progesterone are observed for low, normal and elevated readings. Either Day 1 or Day 3 estradiol testing may be done as part of a panel of tests for polycystic ovarian syndrome (PCOS) or to monitor levels for fertility treatment. Day 21 progesterone testing evaluates the peak luteal levels for women with regular cycles. This can be used to determine if progesterone is optimal for pregnancy or if PMS symptoms are present due to low levels.

Serum estrogen and progesterone testing have limitations. Hormones change vastly throughout the day and can show variations with results if performed when under high stress, recent intense exercise, fasting or other influencing factors. This can lead to a less accurate hormonal profile and may affect treatment options. Women who have irregular cycles may not be able to get an accurate reading due to the variability of levels. Menopausal women or post menopausal women will test low in estradiol and progesterone and serum levels can help to confirm this stage of life. Different physicians will use different mode of testing, serum can be a more simplified test to order, perform and use in some practices.

Saliva hormone testing can provide a more consistently accurate hormone profile than serum in some situations. Saliva testing can more easily provide levels for all 3 types of estrogen and progesterone. The value of having more data and more hormones to evaluate can lead to a more comprehensive protocol plan. Ratios between the hormones can be calculated and insight about risks associated with estrogen might be detected. Many practitioners will use saliva levels to evaluate for proper dosing when prescribing bio-identical estrogen and progesterone therapy. These tests are usually privately paid for by the patient and can only be accessed through a licensed professional. Broader saliva testing can include testosterone, DHEA, cortisol, insulin and gluten reactivity markers along with the 3 types of estrogen and progesterone.

Urine analysis provides the most comprehensive look at hormone production and metabolism. The biochemistry can be interpreted to the greatest extent and the most individualized plan is devised. For a cycling woman, this test is performed around 1 week after ovulation, typically on Day 19, 20 or 21 of a 28 day cycle. This testing window can be shifted depending on cycle length and regularity for optimal analysis. Women who no longer have periods or menstruate infrequently can perform the test too and will be guided as to the optimal timing by their physician.

Urine hormone analysis looks at 4-5 samples of urine at different times of the day. Testing can be performed on dried urine samples, a single urine sample or a 24 hour collection depending on what measures are to be tested. With over 30 markers to view, this form of hormone testing can look at the complicated interactions of all sex hormones and how the body breaks down and eliminates the byproducts. Specifically, urine testing measures the 3 types of E1 metabolites to evaluate bone health risk, cancer risks and confirm if the use of estrogen therapy is safe for an individual. Performing this test prior to using bio-identical hormone replacement therapy (BHRT) is ideal and required by many physicians before prescribing. Urine hormone testing such as this is privately paid for and usually offered by American companies.