Estrogen
Published July 27th, 2026 under Rebirth X
BACKGROUND
Hormones are chemicals that send signals through the body using the bloodstream. The bloodstream signaling system as a whole is known as the endocrine system. Depending on the body’s physiological need, hormones can travel through the endocrine system to target a specific target tissue or affect the whole body in general. In this manner, hormones influence a number of physiological and homeostatic processes such as: metabolism, development, sexual processes, and mood. These varieties of hormones are secreted by different hormonal glands in the endocrine system. The hypothalamus and pituitary gland are the ‘master glands’ of the endocrine system that control when the other glands release certain hormones. Hormones are extremely important for proper bodily regulation.
The main types of hormonal-influenced processes can be categorized into: reproduction and sexual differentiation, development and growth, homeostasis, and regulation of metabolism and nutrient supply. For example, estrogen and testosterone mainly control the first category, somatotropin controls the second, insulin and cortisol influence the third, and glucagon would influence the fourth. Each hormone influences the specific tissue or general area where each category of the processes occur and bind to receptors that trigger the process. In some cases, a hormone may control more than one category or process, but it generally has a main category or process it controls.
WHAT IS ESTROGEN?
Estrogen is a category of female sex hormones. It controls many crucial reproductive and sexual processes in biological women. Males also have estrogen, but in much smaller amounts than women. Estrogen levels additionally fluctuate heavily throughout a woman's life, most noticeably during puberty. Estrogen levels rise during puberty, decline as you approach menopause, rise during the ovulation phase of the menstrual cycle, drop during periods, increase during pregnancy, and decrease at a high rate after childbirth. If there are other irregular fluctuations of estrogen levels, there may be an underlying condition that affects sexual function or other critical organs
There are three main types of estrogen. Estrone (E1), Estradiol (E2), and finally Estriol (E3). Estrone (E1) is primarily produced after menopause, and it is the weakest type of estrogen. It is the only type that a woman’s body produces naturally post-menopause. The second type, estradiol (E2), is the primary form of estrogen in one’s body. It is the most powerful form of estrogen and in some cases, estrone can be converted to estradiol. Estradiol plays a role in releasing mature eggs during a menstrual cycle and thickening the uterine lining. Males have natural estradiol and estrone-converted estradiol as well, and it helps maintain bone health, cognitive function, and the general production of nitric oxide. Lastly, Estriol (E3) is primarily for pregnancies. Estriol levels rise as a pregnancy progresses and fall dramatically after the child is born. Overall, estrogen keeps everyone healthy and it is crucial to have the right amount in our bodies.
HEALTH RISKS & FLUCTUATION
While there are normal fluctuations of estrogen levels as previously discussed, there is still always a healthy range of estrogen. In females, the normal ranges of estradiol throughout the menstrual cycle are: 30 to 100 picograms per milliliter (pg/mL) during the early follicular phase, 100 to 400 pg/mL in the late follicular phase, 50 to 150 pg/mL in the luteal phase, and 2 to 21 pg/mL post-menopause. For males, the normal levels are up to 36 pg/mL at under 18 years old and 10 to 42 pg/mL at ages 18 or above. For estrone, the normal range in females are: 100 to 250 pg/mL during the follicular phase, 15 to 200 pg/mL in the luteal phase, and 15 to 55 pg/mL post-menopause. The general range for males is 15 to 65 pg/mL. Estrogen labs can reveal your estrogen level and an out-of-range level could indicate a health condition.
Abnormal estrogen level could be both a cause and an effect of a disorder or underlying medical condition. Some health conditions associated with imbalances are: amenorrhea and oligomenorrhea, breast cancer (may also affect males), endometriosis, fibrocystic breasts, obesity, osteoporosis (may also affect males), ovarian cancer, PCOS, primary ovarian insufficiency, and PMS. In both sexes, abnormal estrogen levels may also have a role in: Alzheimer’s disease, stomach cancer, infertility, pituitary tumors, schizophrenia, and sexual dysfunction. Aside from these diseases and conditions, doctors may also order an estrogen level blood test if you are getting prostate cancer treatment or have symptoms of menopause /post-menopause to get a better snapshot of your health. There are numerous other reasons why you may need an estrogen test, and your healthcare providers should be transparent regarding this.
CONCLUSION
Hormones are specific chemical signals that control specific categories of functions in your body. Estrogen is a specific category of female sex hormone that mainly controls reproduction and sexual differentiation. The three main estrogens in our bodies are estrone, estradiol and estriol. They each serve different main functions in both females and males that affect overall sexual function and growth. Natural fluctuations occur, however, there is a healthy range of estrogen and an abnormal range could indicate health problems. Therefore, a doctor may order an estrogen lab if they observe signs of abnormal estrogen levels. Having a normal range of any hormone, including estrogen, is crucial to protecting your overall health.
BIBLIOGRAPHY
Cleveland Clinic Medical Team. “Estrogen.” Cleveland Clinic, Cleveland Clinic, 2026, my.clevelandclinic.org/health/body/22353-estrogen. Accessed 15 June 2026.
Cleveland Clinic Medical Team. “Hormones: What They Are, Function & Types.” Cleveland Clinic, Cleveland Clinic, 2022, my.clevelandclinic.org/health/articles/22464-hormones. Accessed 15 June 2026.
Cleveland Clinic Medical Team. “Estrone.” Cleveland Clinic, Cleveland Clinic, 2026, my.clevelandclinic.org/health/body/22398-estrone. Accessed 17 June 2026.
Medline Plus Team. “Hormones | Endocrine Glands.” MedlinePlus, U.S. National Library of Medicine, medlineplus.gov/hormones.html. Accessed 15 June 2026.
Nussey, Stephen. “Principles of Endocrinology.” National Center for Biotechnology Information, U.S. National Library of Medicine, 2001, www.ncbi.nlm.nih.gov/books/NBK20/. Accessed 15 June 2026.
Stárka, Luboslav, and Michaela Dušková. “What Is a Hormone?” PubMed Central, U.S. National Library of Medicine, 1 Sept. 2020, pmc.ncbi.nlm.nih.gov/articles/PMC8603735/. Accessed 15 June 2026.
