Understanding the Changes In Hormone Levels During Postmenopause

Postmenopause is the phase in a woman’s life that comes after reaching menopause, which is diagnosed after 12 consecutive months without a period. This subsequent stage lasts for the remainder of her life. It’s important to note that menopause is a single day, and preceding this day is the perimenopause stage. 
During postmenopause, many women find relief from the uncomfortable symptoms experienced during perimenopause, such as hot flashes, vaginal irritation, and sleep disturbances. In this stage, symptoms often decrease in severity or disappear entirely. At this stage, the reproductive years have concluded, and you’ll no longer ovulate, so you can’t get pregnant (1). Symptoms that usually accompany the perimenopause stage have fluctuating hormone levels to blame. In this article, we’ll go over what those hormones are, how they change during postmenopause, and their effects on women’s bodies.

Postmenopausal Hormone Basics  

Hormones are your body’s chemical messengers. They travel in the bloodstream and carry out their effects on an organ or tissue, work slowly over time, and affect many biological processes (2).

Hormone Levels in Postmenopause

Estrogen

The primary sex hormone for those assigned female at birth, levels fluctuate during every monthly menstrual cycle. During perimenopause, estrogen levels fluctuate, but overall, it will follow a downward trend. Once you reach menopause, your estrogen levels will stay consistently low, and you will no longer ovulate. In addition, the primary form of estrogen changes from estradiol to estrone (3). Estrogen levels in the blood are expressed in picograms per milliliter (pg/mL). Normal levels are 30-400 pg/mL in premenopausal women and 0-30 pg/mL in postmenopausal women (4).

Progesterone 

Works as a team with estrogen to control your menstrual cycle. Also produced in the ovaries, progesterone helps support the early stages of pregnancy. In the early stages of pregnancy, a structure called the corpus luteum, formed from the empty egg follicle, produces progesterone (5). Like estrogen, progesterone levels fluctuate during your perimenopausal years, and levels remain low once you are in postmenopause (6). Expressed in nanograms per milliliter (ng/mL), levels of progesterone vary greatly depending on what phase of your menstrual cycle you are in. However, they remain low once postmenopause is reached and can range from less than 1ng/mL to 3.18ng/mL (7).

Testosterone

This male androgen hormone is also produced in women at lower levels and also declines in your postmenopause years. It is produced in your ovaries as well as your adrenal glands. Levels will peak in your 20s and slowly decline after that. Testosterone is involved in your body’s estrogen production, contributes to libido, and may help maintain muscle and bone mass. The effects of testosterone decline in midlife are uncertain. It remains controversial that declines in testosterone may dampen libido in middle-aged women, and it’s thought that the decline is solely age-related, not menopause-related, as it begins years prior to perimenopause. Once menopause is reached, testosterone levels are about half what they were when they peaked in your 20s (8).

Follicle Stimulating Hormone (FSH)

Made and released by your pituitary gland, FSH plays an important role in sexual development and reproduction (9). FSH causes the enlargement of ovarian follicles, which then produce estrogen. As we age, there are increasingly fewer follicles remaining that can be stimulated by FSH. In turn, less estrogen is produced, and the body pumps out more FSH since there is not enough estrogen to “turn off” FSH production (10). So alternative to estrogen and progesterone, FSH will have elevated levels. A single reading of FHS levels may be misleading during perimenopause as levels can vary greatly. When your level of FSH is consistently elevated to 30 mIU/mL (milli-international units per milliliter) or higher, and you have not had a period for 12 consecutive months, it is generally accepted that you have reached menopause (11).

Luteinizing Hormone (LH)

Like FSH, LH is produced in your pituitary gland and spurs changes in your ovaries to allow for normal reproductive function. During your menstrual cycle, a surge in LH results in ovulation. LH also encourages the corpus luteum to secret progesterone during the 3rd and 4th week of the menstrual cycle. LH levels will increase as you go through the menopause transition as estrogen and progesterone levels fall (12). Expressed in international units per liter (IU/L), levels of LH before menopause are 5-25 IU/L, while postmenopause levels become higher, ranging from 14.2-52.3 IU/L (13). 

Hormone levels can help your doctor understand what is happening in your body. A single reading of hormone levels can sometimes be misleading as hormone levels fluctuate. Currently, there is no simple test to predict or confirm if you have reached menopause or even perimenopause, but research is progressing. Monitor your menstrual cycles and check in with your healthcare provider to gain insight on what stage your body is in (11). 

References: 

1. Cleveland Clinic. (n.d.-a). Postmenopause: Signs, symptoms & what to expect. https://my.clevelandclinic.org/health/diseases/21837-postmenopause 

2. U.S. National Library of Medicine. (2016, October 7). Hormones | endocrine glands. MedlinePlus. https://medlineplus.gov/hormones.html 

3. Cleveland Clinic. (n.d.). Estrogen: Hormone, function, Levels & Imbalances. Estrogen. https://my.clevelandclinic.org/health/body/22353-estrogen   

4. University of Rochester Medical Center. (n.d.-c). Estradiol (blood). https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=estradiol 

5. Cleveland Clinic. (n.d.-c). Progesterone: Natural function, levels & side effects. https://my.clevelandclinic.org/health/body/24562-progesterone 

6. Cleveland Clinic. (n.d.-c). Postmenopause: Signs, symptoms & what to expect. https://my.clevelandclinic.org/health/diseases/21837-postmenopause  

7. University of California San Francisco . (2020, October 6). Serum progesterone. https://www.ucsfhealth.org/medical-tests/serum-progesterone 

8. The North American Menopause Society NAMS. (n.d.). Changes in hormone levels. Changes in Hormone Levels, Sexual Side Effects of Menopause. https://www.menopause.org/for-women/sexual-health-menopause-online/changes-at-midlife/changes-in-hormone-levels

9. Cleveland Clinic. (n.d.-a). Follicle-stimulating hormone (FSH): What it is & function. https://my.clevelandclinic.org/health/articles/24638-follicle-stimulating-hormone-fsh 

10. Perelman School of Medicine at the University of Pennsylvania. (n.d.). Menopause. Penn Center for Women’s Behavioral Wellness . https://www.med.upenn.edu/womenswellness/menopause.html 

11. The North American Menopause Society, NAMS. (n.d.-f). How do I know when I’m in Menopause? https://www.menopause.org/for-women/menopauseflashes/menopause-symptoms-and-treatments/how-do-i-know-when-i'm-in-menopause-

12. Cleveland Clinic. (n.d.-b). Luteinizing hormone: Levels, function & testing. https://my.clevelandclinic.org/health/body/22255-luteinizing-hormone 

13. Mount Sinai Health System. (n.d.-g). Luteinizing hormone (LH) blood test. https://www.mountsinai.org/health-library/tests/luteinizing-hormone-lh-blood-test