Low Estrogen Levels: About & Causes

It is natural for estrogen to fluctuate for women as it guides menstruation on a monthly basis. However, what generates issues is when estrogen levels are excessively lower than normal, causing many unwanted symptoms.

Continue reading to learn about low estrogen levels and what can cause unnatural fluctuations, including hormonal and lifestyle-related triggers.

About Low Estrogen Levels

Estrogen and Menstruation

During the menstrual cycle, estrogen steadily increases during the follicular phase. With the final spike in estrogen immediately before ovulation, the egg is released from a matured follicle during an act known as ovulation. Subsequently, estrogen levels decline for the second half of the cycle - the luteal phase - until the next cycle.

In adulthood, it is normal for monthly estrogen levels to span from 30 - 400 pg/mL, depending on age and stage in the menstrual cycle. However, most women will experience abnormal drops in estrogen sometime during their lifetime, and they can be caused by a variety of factors.

Causes of Low Estrogen Levels

For all intents and purposes, the causes of low estrogen levels will be divided into four categories: natural causes, lifestyle factors, induced causes, and other causes.

Continue reading to learn more about the root of what causes hormonal imbalance for a healthier overall well-being.


Natural Causes of Low Estrogen Levels

During Adulthood (20s to 40s)

Recall that estrogen fluctuates on a monthly basis with the menstrual cycle. However, low estrogen in women is also naturally caused by childbirth and breastfeeding.

When a woman is pregnant, the placenta produces the majority of estrogen - estriol - starting around the ninth week of pregnancy until full term. After delivery of the placenta during childbirth, estrogen levels drastically decrease within the following 24 to 48 hours.

In over half of women, these levels are so low that they resemble those of menopausal women. Depending on the woman, estrogen levels may remain low for several months after childbirth, especially if breastfeeding.

Breastfeeding poses a time in a woman's life in which her estrogen levels will naturally be low due to the causal relationship between prolactin levels and the absence of ovarian activity. Blood levels of prolactin will remain high for those women who breastfeed after delivery; in this way, suppressed estrogen levels acts as a form of birth control to help space out pregnancies.

During these times, low estrogen symptoms may ensue since the hormone is in charge of endocrine and reproductive system health. These symptoms include migraines, irritability, decreased libido, and more.

During Perimenopause and After Menopause (40s on up)

Estrogen and Menopause

As a woman's body expends her eggs through continuous menstruation cycles, the total number decreases over time and leads to a corresponding decline in the secretion of estrogen. This continues until menstruation ceases, and menopause begins.

This decline in estrogen levels is predominantly what causes the host of symptoms that women experience during this time, including night sweats, vaginal dryness, mental fogginess, hot flashes, and more.

During this time, using conventional measures - such as HRT - or supplementing with bioidentical estrogen products - such as pills, creams, patches, and gels - may provide a hormonal boost needed for healthy endocrinal health. Postmenopausal women may also choose more natural treatments in the form of herbal supplements that nourish hormonal glands for improved functioning.


Lifestyle Factors that Cause Low Estrogen Levels

Also, there are a variety of lifestyle factors that can cause low estrogen levels. Some of them include, but are not limited to, the following:

  • Diet. Fatty foods have a very strong influence on hormonal activity in the body. It has been found that with high-fat diets, estrogen levels increase. However, the opposite is also true; low-fat diets will cause estrogen levels to drop significantly in a short amount of time. Consequently, vegetarians tend to have significantly lower estrogen levels than non-vegetarians due to their diets having lower fat contents.

  • Stress. Extreme levels of stress can disrupt hypothalamic function, which stimulates and regulates activities of other endocrine glands. This stress-induced dysfunction can cause estrogen deficiency. Moreover, research has proven that days with higher perceived levels of stress are characterized by lower levels of estradiol in women's saliva, further proving the negative effects of psychological stress on ovarian estrogen production. 

  • Eating disorders. Eating disorders, such as anorexia nervosa, can cause an estrogen deficiency because low body weight in females can prompt the body to stop producing estrogen, which consequently results in amenorrhea - a lack of menstruation - and further medical concerns. Likewise, extreme dieting can also cause an estrogen deficiency; women who adopt low-fat diets have estrogen levels that drop significantly in short periods of time. 

  • Estrogen Low Levels Cycle

    Extreme exercise. Just as anorexia can cause a drop in weight, extreme exercising can also cause a woman to have insufficient body fat, leading to amenorrhea. Exercise-induced amenorrhea causes the body to believe it is in a “starvation state,” thereby shutting down bodily operations not deemed necessary for survival, such as those of the reproductive system. Also, increased stress from excessive exercising can interfere with continuous cycles of healthy menstrual periods. 


Induced Causes of Low Estrogen Levels

Various procedures and treatments can cause women to have lower estrogen levels, including hysterectomies, radiation therapies, and certain medications.

Hysterectomies involve the surgical removal of reproductive organs. Women who have their ovaries removed - as part of a total hysterectomy, or “surgical menopause” - can suffer from decreased estrogen levels as it halts ovarian hormone production.

Following a partial hysterectomy in which just the uterus is removed can also force a woman to enter surgically-induced menopause. She'll most likely experience a hormone imbalance, regardless of whether or not her ovaries remain. Typically, the ovaries stop working within one to three years afterwards as blood flow to them ceases.

Another cause of low estrogen levels in girls and women is chemotherapy or radiation therapy treatments. Loss of ovarian function can be permanent or temporary, and functions may halt as soon as two to three weeks into treatment. The performance of the ovaries depends upon the type of chemotherapy received and whether or not radiation was utilized on the ovaries.

Moreover, use of exogenous hormones for other medical conditions can also trigger low estrogen levels. Drugs such as rifampicin, barbiturates, warfarin, primidone, and more decrease estrogen levels in women's bodies by enhancing the hormone's metabolism in the liver.


Other Causes for Low Estrogen Levels

Moreover, the following conditions can each prompt low levels of estrogen in women:

  • Congenital conditions. Genetic predispositions, such as Turner syndrome, estrogen insensitivity syndrome, and aromatase deficiency, can all cause a woman to have lower estrogen levels.
  • Abnormal gland function. Thyroid disorders and pituitary gland diseases have both been found to provoke lowered estrogen levels in women by inducing amenorrhea and offsetting hormones that aid in the secretion of estrogen.
  • Delayed puberty. Delayed pubertal development can provoke variety of health conditions, improper ovarian development being one of them. 


Overall, there are a range of factors as well as natural, induced, and other causes that can provoke low estrogen levels throughout a woman's reproductive life.

Careful vigilance of hormonal imbalance is important before conditions become severe complications with an estrogen deficiency. Therefore, continue reading to learn more about the signs and symptoms of low estrogen.


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  • Fisher, E. (2015). Understanding Your Fertility while Breastfeeding. Retrieved August 15, 2017, from https://breastfeedingusa.org/content/article/understanding-your-fertility-while-breastfeeding
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  • National Institutes of Health. (2016). What People With Anorexia Nervosa Need to Know About Osteoporosis. Retrieved August 16, 2017, from https://www.niams.nih.gov/Health_Info/Bone/Osteoporosis/Conditions_Behaviors/anorexia_nervosa.asp
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  • The Physicians Committee. (n.d.). Fat and Hormonal Effects. Retrieved August 17, 2017, from https://www.pcrm.org/health/cancer-resources/diet-cancer/nutrition/fat-and-hormonal-effects
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