Progesterone is a sex steroid hormone that plays an essential role in regulating menstruation and supporting women's reproductive health. It also acts on other bodily processes and impacts cognitive outcomes, body temperature, memory, and age-related clinical conditions. So exceptionally high or low levels of progesterone can have various health implications that should be addressed with a healthcare provider. [1]
A progesterone blood test—also known as a P4 test—measures this hormone at that given point in time. The challenge is deciphering what your results mean for you, putting those results in the context of other health markers, and getting insurance to cover the cost of the test.
InsideTracker now tests blood progesterone levels for females as part of the Ultimate Plan, providing insight into what your levels mean, and unpacking how they may affect other areas of your health. When you measure progesterone with InsideTracker, your personal health analysis breaks down precisely what your results mean in relation to your current lifestyle habits, menopausal state, contraceptive use, and other blood biomarker levels.
But for now, let’s dive into the basics of what you should know about progesterone blood testing.
What is progesterone?
Progesterone is primarily produced by the adrenal cortex as well as the ovaries. This steroid hormone is vital to women's reproductive health and is critical in the menstrual cycle, pregnancy, and the development of an embryo. A rise in blood progesterone levels is responsible for preparing the body for a potential pregnancy—and a subsequent decline in progesterone blood levels in the absence of a pregnancy results in a menstrual period. [1]
So, progesterone levels readily fluctuate in the second half of the menstrual cycle. Levels continue to fluctuate during perimenopause and decline in postmenopause. The extent to which progesterone levels decline can increase the severity of vasomotor symptoms—like hot flashes and night sweats—many women experience during menopause. [2]
In menstruating women, high progesterone levels are associated with additional health factors, including cognitive outcomes and increases in core body temperature which can impact sleep quality. Low progesterone levels can contribute to a surge in estrogen levels, resulting in irregular periods and spotting. [3]
Do men produce progesterone?
Everyone does produce and utilize progesterone, including men. Progesterone is produced in the adrenal glands and the testes and is required for healthy testosterone production in men. [4]
*As of now, progesterone is only included in InsideTracker’s Ultimate Plan for those who select female when they activate their test. The sex-based insights at InsideTracker are informed by biological sex, and if you use Gender Affirming Hormone Therapy, select the biological sex o
What is the reference range for a progesterone blood test?
Blood test results are typically displayed against a reference range. Levels that fall above or below that range should be addressed with your healthcare practitioner, as they may indicate a medical concern.
The reference range for progesterone differs by multiple factors like menstrual cycle phase at the time of the test, hormonal contraceptive use, and menopausal status. [5]
| Normal reference range for progesterone |
||
Premenopause |
Natural cycle, follicular phase | 0-1 ng/mL |
| Natural cycle, luteal phase | 2.6-21..5 ng/mL | |
| Hormonal contraceptive use | 0-3 ng/mL | |
| Perimenopause | Natural cycle, follicular phase | 0-1 ng/mL |
| Natural cycle, luteal phase | 0.48-19 ng/mL | |
| Hormonal contraceptive use | 0-3 ng/mL | |
| Postmenopause | All postmenopausal women | 0-0.5 ng/mL |
| Men | All adult males | <1.4 ng/mL |
Progesterone throughout the female lifespan
Progesterone levels fluctuate in cyclical patterns in premenopausal and perimenopausal women and become relatively stable in postmenopausal years. During each phase of the menstrual cycle, progesterone levels can fall outside of that normal range. And at each life stage, the impact of those altered levels has implications on the body and overall health. [2]
Let’s dive into what progesterone levels mean for pre, peri-, and postmenopausal women.
Progesterone levels in premenopausal women
Progesterone levels rise and fall readily throughout the menstrual cycle. Levels are lowest during the early follicular phase (menses) and peak during the seven to eight- day luteal phase. The peak in progesterone during the luteal phase triggers the thickening of the uterine lining to prepare for a potential fertilized egg to implant and prohibits muscle contractions in the uterus. In the absence of a new pregnancy, progesterone levels in the body decline, resulting in a menstrual period. [1]
Hormonal contraceptive use—such as taking the pill or having an implant—stabilizes these peaks and dips of progesterone by curbing the increase of the hormone during the luteal phase of the menstrual cycle. This leads to more consistent progesterone levels throughout the entire menstrual cycle. [6]
What do low levels mean?
Low progesterone levels can contribute to a surge in estradiol levels—as these two hormones are intimately connected. Low progesterone levels impact the thickening of the uterine lining (also called the endometrium) before it sheds and can contribute to heavy periods, irregular periods, and spotting. [1]
What do high levels mean?
Research shows that high progesterone levels are associated with increased worry and decreased working memory accuracy in women. The rise in progesterone levels during the luteal phase prepares the female body for possible pregnancy and may intensify women's need to generate a safe and supportive environment, potentially increasing feelings of worry and anxiety. [2, 7]
Prolonged high levels of progesterone may have clinical implications, including endometrial hyperplasia—a condition where the lining of the uterus is abnormally thick. Because high progesterone levels may indicate clinical conditions, talk with a healthcare professional about elevated levels. [1]
Progesterone levels in peri- and postmenopausal women
Progesterone levels tend to decline in peri- and postmenopausal women.
During the perimenopausal years, progesterone levels are often in flux as menstrual cycles occur less regularly until the onset of menopause—when a woman hasn't experienced a menstrual cycle in 12 months. So the body slows progesterone production, resulting in lowered blood progesterone levels. Progesterone levels continue to decline as a woman enters postmenopause. [8]
The flux in progesterone levels during the perimenopausal years can indirectly affect sleep through its impact on body temperature. Elevated progesterone levels can promote heat conservation, raising body temperature. Higher core body temperature promotes wakefulness and makes it harder to fall asleep. [9]
What do low levels mean?
Low progesterone levels are linked to symptoms like heightened mood and difficulty sleeping, which are common menopause symptoms. It’s important to note that every woman experiences menopausal symptoms a bit differently. [7]
What do high levels mean?
Prolonged high levels of progesterone may have clinical implications—including conditions that should be discussed with your healthcare provider. [1]
How do progesterone levels affect other blood biomarker levels?
Progesterone is intricately connected to multiple biological systems—and scientific literature points to a connection between progesterone levels and other blood biomarkers.
The chart below describes how certain biomarkers are correlated to progesterone during pre- and postmenopause, and the mechanism behind it.
| Impact of elevated progesterone on other blood biomarkers |
|||||
| Premenopause | Increased hsCRP | In premenopausal women, elevated progesterone levels are associated with increased hsCRP levels. Researchers hypothesize that this association is observed because progesterone can increase the production of certain inflammatory mediators. |
|
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| Postmenopause | Increased blood glucose + HbA1c | Studies point to a connection between elevated progesterone levels and increased levels of blood glucose and HbA1c in postmenopausal women—however, further research is required to determine the mechanism behind this association. [11] | |||
Can you improve unoptimized progesterone levels?
Progesterone levels that fall outside of the reference range should be addressed with a healthcare practitioner, who can account for your full medical history.
InsideTracker’s personalized health analysis displays progesterone blood test results using the reference ranges provided and takes the analysis a step further by creating optimal based on menopausal status (pre, peri-, or postmenopausal), menstrual cycle phase, and more. For blood test results that fall outside of a given optimal zone, a person may see recommendations for food, supplements, and/or physical activity recommendations that can positively sway progesterone to optimal levels.
How can you get your progesterone levels measured?
Knowing your progesterone levels can provide critical insight into your hormone health and help guide your next course of action, whether that’s no change to your current routine or speaking with your physician about your results.
But a progesterone blood test isn’t always included in standard bloodwork.
When you measure your progesterone with InsideTracker’s Ultimate Plan, you can track your levels over time and understand its impact on your other biomarkers. Continuously reassessing progesterone levels is a critical component of health management, as suboptimal levels are associated with notable symptoms and disease risks. Estradiol, thyroid-simulating hormone, sex hormone binding globulin, and DHEAS are also measured in that panel
Suboptimal progesterone levels can have clinical implications, and you should reach out to your healthcare provider.
Since progesterone levels vary depending on where a person is during their menstrual cycle or whether they are on contraceptives, the ideal time to have your levels tested does change. Check out these recommendations on when InsideTracker recommends you get progesterone levels tested.
References:
[1] https://www.ncbi.nlm.nih.gov/books/NBK558960/
[2] https://pubmed.ncbi.nlm.nih.gov/17550960/
[3] https://pubmed.ncbi.nlm.nih.gov/34090137/
[4] https://pubmed.ncbi.nlm.nih.gov/15669543/
[5] https://testdirectory.questdiagnostics.com/test/test-detail/745/progesterone?cc=MASTER
[6] https://pubmed.ncbi.nlm.nih.gov/2387151/
[7] https://pubmed.ncbi.nlm.nih.gov/31693131/
[8] https://pubmed.ncbi.nlm.nih.gov/30401546/
[9] https://pubmed.ncbi.nlm.nih.gov/28488202/
