Estrone is one of the lesser-known estrogens. It has very little activity compared to the more ubiquitous estradiol. After menopause, however, estrone becomes the primary source of estrogen in women. Learn more about estrone testing and the health effects of low and high levels.
What is Estrone?
Overview of Estrogens
You’re probably familiar with estrogen, the primary sex hormone found in women (and in much lower amounts in men) .
But did you know that estrogen is actually a broad term that covers several hormones?
There are 3 major estrogens, all of which act on the estrogen receptor. What differentiates them is how potent they are and where they are produced in the body .
- Estradiol (E2) is the strongest estrogen. It is responsible for most of the effects we associate with estrogen, such as sexual development in girls and young women .
- Estrone (E1) stimulates the estrogen receptor about ten times more weakly than E2. Estrone is produced in the ovaries (similar to other estrogens) but also in fat tissue .
- Estriol (E3) is even weaker than estrone. Levels of estriol are very low in women unless they are pregnant .
What Does Estrone Do?
Estrone mostly acts as a precursor to estradiol. Then the body is able to convert estrone into estradiol when needed .
This conversion is especially important in postmenopausal women. Before menopause, estradiol is the most common estrogen. Once menopause occurs, the body stops producing estradiol. This leaves estrone as the only major estrogen (and the only potential source of estradiol) found in postmenopausal women .
Your doctor may order an estrone test if you are experiencing menopausal symptoms or infertility problems. Your estradiol levels may also be checked simply to get a full picture of your estrogen production .
An estrone test will usually require a blood sample, but tests that use a saliva sample are also available. Saliva tests can be easier to do because they don’t require needles, and people can collect their own samples at home if necessary. The trade-off is that the results can be inaccurate if the sample is not properly collected .
Test results are reported as a numerical value in units of picograms per milliliter (pg/mL). This value reflects the amount of estrone in the blood (or saliva depending on the type of test).
Normal Estrone Levels
Normal ranges can vary depending on the lab performing the test. Estrone levels also differ depending on age and gender .
The normal range for adult men is around 12 to 72 pg/mL.
Younger men and adolescent boys will generally have lower levels, depending on their stage of physical development .
Estrone ranges in women are a bit more complicated. Levels can vary greatly depending on where they are in their menstrual cycle. Pregnancy and menopause will also effect estrone levels .
For each stage of the menstrual cycle, the normal range is :
- Follicular phase, during a woman’s period and up to ovulation: 37 to 138 pg/mL
- Mid-cycle, around the time of ovulation: 60 to 229 pg/mL
- Luteal phase, the last two weeks leading up to the next period: 50 to 114 pg/mL
In postmenopausal women, the normal range is about 14 to 103 pg/mL, while in pregnant women, estrone levels can shoot up as high as 11,500 pg/mL. The placenta, which makes many of its own hormones, is responsible for these exceptionally high levels .
Girls and younger women will have lower levels of estrone, depending on how far along they are in physical development. Most girls reach the equivalent of adult levels of estrone during the stage of puberty when they have their first period [9, 10].
Tests using saliva samples have a different set of reference ranges, simply because there is normally less estrone in saliva than in blood .
The normal range for adult men is 1.3 to 3.6 pg/mL .
For premenopausal women, the normal range is 3.2 to 7.9 pg/mL .
For postmenopausal women, the normal range is 0.9 to 3.1 pg/mL .
The amount of research done on estrone is quite limited, especially compared to estradiol. It’s not entirely clear what the optimal level of estrone is for the body.
High Estrone Levels
Causes shown here are commonly associated with high estrone. Work with your doctor or other health care professional for an accurate diagnosis.
1) Estrogen Medications
Women who receive estrogen therapy (also called hormone replacement therapy or HRT) will have higher estrone levels. HRT is most commonly prescribed to postmenopausal women suffering symptoms like hot flashes and night sweats [14, 15].
Even when taking estradiol medications or other synthetic forms of estrogen, levels of estrone can still rise. This is because estradiol can be converted into estrone in the body .
In one study, postmenopausal women who received estradiol therapy saw an average increase of about 260 pg/mL in their estrone levels .
While mostly discontinued, estrone itself is available as a medication for symptoms of menopause. Taking estrone-containing medications will, of course, increase estrone levels as well .
Postmenopausal women taking estrogen drugs will need to check different reference ranges when evaluating their estrone levels .
At first, this one seems counterintuitive. After all, estrogen levels fall off after menopause because the ovaries stop producing estradiol. However, there’s an odd relationship between age and hormone replacement therapy that may result in increased estrone in older women .
A study found that older women who take estrogen have higher estrone levels compared to younger women taking the same medication. This is likely due to the reduced metabolism of elderly people. Older women may be slower at eliminating hormones (such as estrone) from the body .
Another case where age matters is in prostate enlargement, a condition that affects men. A study of 25 men with enlarged prostates found that estrone levels increased significantly with age .
One study of 180 postmenopausal women found that estrone levels are linked to BMI. This association becomes stronger as women get older .
Interestingly enough, it appears that visceral fat (the fat in the abdomen that surrounds the organs) produces the most estrone, while subcutaneous fat (the layer of fat under the skin) produces more estradiol .
4) Liver Disease
Liver diseases like cirrhosis (scarring of the liver) may cause small increases in estrone levels, possibly because of increased conversion of male sex hormones (androgens) to estrone and estradiol [22, 23].
A small study of 18 men found slight increases in men with alcohol-related cirrhosis, cardiac cirrhosis, and hepatitis .
The same effect is seen in women as well. One study compared estrone in postmenopausal women with or without cirrhosis. They found that the women with cirrhosis had, on average, estrone levels that are 46 pg/mL higher than healthy women .
Some older studies suggest that estrone levels become elevated in people with an overactive thyroid gland (hyperthyroidism) .
One study found that concentrations of estrone are high in men with Graves disease, a form of autoimmune hyperthyroidism. In another study, estrone levels were also raised, but only in half of the hyperthyroidism patients [25, 26].
6) Adrenal Gland Tumors
Cancer of the adrenal gland can cause the gland to release too many hormones. In very rare cases, tumors in the adrenal glands can secrete high amounts of estrogens. This can lead to high levels of all estrogens, including estrone, which can cause a number of hormonal issues [28, 29].
7) Ovarian Cancer
Estrogens are primarily made in the ovaries in premenopausal women. Unsurprisingly, ovarian tumors often overproduce estrogens, including estrone .
A study of 581 women found that estrone levels are significantly higher in women with ovarian cancer .
1) Breast Cancer
High estrogen levels can increase the risk of a type of breast cancer called estrogen receptor-positive (ER+). In this form of breast tumor, the cancer cells are able to use estrogens to stimulate their own growth .
On the other hand, there is estrogen receptor-negative (ER-) breast cancer. This cancer is less common but can be more dangerous. These two types of breast cancer often have different risk factors and treatments .
High estrone levels are associated with ER+ breast cancer, according to a study of 144 postmenopausal women. However, estrone did not affect the risk of ER- breast cancer .
In fact, another study of 358 postmenopausal women found that high estrone levels actually reduce the risk of death in people with ER- tumors .
2) Ovarian Cancer
As mentioned earlier, ovarian cancer may increase the level of estrone in the body. The inverse may also be true: high estrone levels can increase the risk of ovarian cancer .
In a clinical trial of 581 women, higher levels of estrone were linked to increased rates of ovarian cancer, although the increase was modest .
3) Diabetes in Men
Estrogen levels on the high end of normal can protect against type 2 diabetes in postmenopausal women. However, research suggests this may not be true in men. In fact, high estrone may actually increase the risk of men developing diabetes [38, 39].
A study of 1458 men found a significant correlation between high estrone levels and the likelihood of having diabetes. On top of that, men with twice the normal amount of free estrone were 93% more likely to develop diabetes than those with average levels .
4) Symptoms of High Estrogen
Ways to Decrease Estrone
If your doctor determines that your estrone (or other estrogen) levels are too high, they will likely have strategies and recommendations for you to try, which may or may not include the strategies in this section. Talk to your doctor before making significant changes to your diet, lifestyle, or supplement regimen, and never use these strategies in place of something your doctor recommends or prescribes.
1) Exercise and Weight Loss
Bodyweight and estrone levels are closely linked. Estrone is made in visceral fat; thus, the more fat there is in the abdomen, the more estrone is produced .
At the 3 month mark, there was already a noticeable decrease in estrogen levels, with estrone decreasing by about 4%. At the end of the year, the total estrone reduction was about 12% .
However, this lowering effect was only seen in women who lost body fat; it follows that you have to decrease fatty tissues to effectively decrease estrone .
2) Dietary Fiber
Increased intake of dietary fiber decreased estrone in a study of 242 postmenopausal women .
More specifically, women that ate fiber-rich diets had estrone levels that are 22% lower than women who got comparatively little fiber .
The researchers theorize that lignin, a fiber that gives woody plants their structure, may play a major role. Lignin binds to some compounds (including, possibly, estrogens), deactivates them, and makes it easier for the body to remove them. Examples of lignin-rich foods include carrots, broccoli, and whole grains .
3) Anti-Estrogenic Foods
Certain foods may help reduce estrone by blocking an enzyme called aromatase. This enzyme is responsible for converting androgens (male hormones) into estrogens .
It is unclear whether eating foods that contain aromatase inhibitors could decrease estrone in human blood; clinical studies are lacking.
Some foods that contain natural aromatase blockers include :
- Brussels sprouts
4) Avoiding Alcohol
Those wanting to decrease their estrone levels may want to avoid drinking any alcohol. A study of 244 postmenopausal women found that those who drank even a moderate amount of alcohol had increased estrogen levels .
According to one study, premenopausal women who drank more than 10 g of alcohol each day had 18% higher estradiol levels than women who did not. The effect on estrone was not measured .
This estrogen-elevating effect may be due to alcohol increasing the activity of aromatase, the enzyme that produces estrogens .
5) Green Tea
Another study in 130 postmenopausal women found similar results. Those who regularly drank green tea had 13% lower estrone levels than those who did not .
Low Estrone Levels
Causes shown here are commonly associated with low estrone. Work with your doctor or other health care professional for an accurate diagnosis.
Estrone is the primary estrogen in women’s bodies after menopause. The ovaries stop producing estrogens after menopause, including estrone. Even though estrone can still be made in other tissues, the overall level of estrone is likely to fall .
Aromatase inhibitors (like letrozole, anastrozole, or tamoxifen) are a group of medications used to treat certain types of breast cancer. They work by blocking aromatase, an enzyme that helps create estrogen in the body .
By blocking estrogen production, aromatase inhibitors reduce estrone levels. In fact, one study found that letrozole reduces estrone to almost undetectable levels .
There is some evidence that NSAIDs (like ibuprofen, naproxen, and aspirin) may also lower estrone levels, at least in men .
A study including 1766 men found that use of prescription or over-the-counter NSAIDs was associated with lower estrone levels, but only in obese men .
1) Heart Disease
Postmenopausal women with heart disease who have estrone levels below 15 pg/mL are at a greater risk of dying, according to one study .
Another recent study in 304 women might explain exactly how estrone contributes to heart health. They found that estrone improves the function of the endothelium, the innermost layer of the heart that helps control contractions (and, thus, the rhythm of the heart) .
2) Metabolic Syndrome
Low estrogen levels contribute to nearly all of the symptoms associated with metabolic syndrome. This is why postmenopausal women are more likely to have metabolic syndrome compared to premenopausal women [67, 66].
3) Symptoms of Low Estrogen
A variety of symptoms are associated with low estrogen levels, many of which are also seen during menopause .
Ways to Increase Estrone
If your doctor determines that your estrone (or other estrogen) levels are too low, they will likely have strategies and recommendations for you to try, which may or may not include the strategies in this section. Talk to your doctor before making significant changes to your diet, lifestyle, or supplement regimen, and never use these strategies in place of something your doctor recommends or prescribes.
It’s no secret that the milk you buy from the store is full of hormones, including estrogen .
But what effect does this have on people who drink cow’s milk?
A study including men, women, and children tested this by giving participants 500 mL or more of cow’s milk for up to 21 days. They found that concentrations of estrone increased significantly for everyone in the study .
2) Black Tea
According to a study of 130 postmenopausal women, black tea may help boost estrone levels. Researchers discovered that estrone levels in regular black tea drinkers were 19% higher than in women who drank little to no black tea .
3) Avocado and Grapefruit
A study of 242 postmenopausal women found that those who ate the most avocados had estrone levels that were 26% higher than those that did not eat as much. Similarly, the top eaters of grapefruit had 29% higher levels of estrone .
Yoga is great for mental health and has been shown to improve quality of life. There is some evidence that yoga may have biological effects as well: in a case report of 2 postmenopausal women, estradiol levels increased after 4 months of yoga [77, 78].
Estrone is one of the weaker types of estrogen. However, it is the main source of estrogens in postmenopausal women. For women, estrone levels can vary wildly depending on a number of factors, including the stage of their menstrual cycle, if they’ve gone through menopause, and if they are pregnant.
Broadly speaking, normal levels are between 37 pg/mL (low point during periods) and 229 pg/mL (high point during ovulation). In adult men, estrone levels should remain fairly constant throughout their lifetime, with a normal range being about 12 to 72 pg/mL.
If your estrone levels are too low or too high, your doctor may recommend strategies for increasing or decreasing them. Getting more exercise and fiber in the diet may help decrease estrone; certain foods like milk, black tea, avocados, and grapefruit might help raise it.