The Beginner’s Guide to Estrogen Blockers for Men

Hormones are chemical messengers that communicate with our bodies. They are secreted from the endocrine glands and guide the body to perform several tasks (1).

They play a very important role in controlling the basic body functions like metabolism, growth and sexual development.

Estrogen and testosterone are the sex hormones that facilitate the function of our reproductive system. Both hormones play their own significant role in both sexes and perform a number of functions aside from their reproductive roles. This makes their balance so critical to health.

Any form of disbalance disrupts this equilibrium and results in undesirable changes. To combat this change we use hormone blockers or hormone boosters. Estrogen blockers are one such supplement that has been extensively used these days.

What Are Estrogen Blockers?

Estrogens are hormones that are responsible for sexual and reproductive development in the female. It is an entire class of related hormones that include estriol, estradiol, and estrone (2).

It helps in developing and maintaining both the reproductive system and female secondary sexual characteristics such as breasts. There are presently 300 known functions for estrogen in the body.

Testosterone is the male sex hormone that is responsible for regulating fertility, increasing muscle mass, increasing bone density, production of red blood cells and sperms, maintenance of muscle strength, and distribution of fat in men (3).

It is interesting to note that even men need estrogen but in a smaller dose (4). Estrogen needs to stay in balance. Estrogen and testosterone are interconvertible which is made possible by the enzyme aromatase. But as we age, hormone production and this balance changes which impart multiple changes. When estrogen crosses the normal line, estrogen blockers are used.

Estrogen blockers are supplements that either stop the cells from making estrogen or block the cells from using estrogen. Estrogen blockers are very similar to the testosterone boosters but they specifically work on the production of estrogen. Estrogen blockers act as aromatase inhibitors.

Why Do Some Men Need Estrogen Blockers?

The five main reasons for which estrogen blockers are used in men are:

  • As men grow, their testosterone production also increases reaching a peek at their teens. From the time they are 30 years, it starts reducing by 0.4 to 2 percent every year (5). Even though it is a natural phenomenon, for some men it is too fast and the reduction is too low. This disrupts the sensitive balance of the hormones and results in undesirable effects. An estrogen blocker is a solution.
  • If for some reason, the testosterone level drops below the healthy line, it can lead to an increase in estrogen (6). That, in turn, may lead to gynecomastia (which is enlarged breast tissue), a drop in sperm production, loss of libido, decrease in muscle mass and erectile dysfunction. It may also lead to weight gain and prostate problems. These are the times when estrogen blockers are used.
  • For men who can’t produce enough testosterone and have to undergo testosterone replacement therapy (TRT) in the form of estrogen blockers, use them.
  • As a treatment for some cancers estrogen blockers are used (7). These are prostate, breast, ovary and uterus cancers.
  • Athletes, bodybuilders, and men who are looking for enhanced muscle growth and adaptation with exercise use estrogen blockers to reduce estrogen and increase the testosterone level (8). This ensures more efficient fat metabolism and metabolically active muscles.

5 Natural Estrogen Blockers

The four natural products that have shown promises as estrogen blockers are:

Wild Nettle Root

Wild Nettle root contains compounds that block the estrogen naturally. Hence, the roots or the leaves are used to make prostate medication in which the most important line of treatment is estrogen blockage. It helps in regulating the hormone, estrogen.


Chrysin is a natural flavonoid that is found in passionflower, honey, and bee propolis (9). The balance between testosterone and estrogen is controlled by the enzyme, aromatase. It converts testosterone into estrogen. Chrysin has been found to be an inhibitor of aromatase enzyme activity. It is nowadays used by the sportsmen for their properties.


Maca root, also known as Peruvian Ginseng, is a cruciferous plant that is cultivated in South America, predominantly in Peru. It is packed with medicinal benefits and has been known to be a natural estrogen blocker (10). Maca does not have a direct impact on the testosterone level.

The unique set of chemicals called “alkalymides” in maca nourishes the endocrine system which is crucial in testosterone production. Maca roots are loaded with DIM which is a strong estrogen blocker.

Grape seed extract

Grapeseed oil is a byproduct of winemaking. Procyanidin dimers that are high in it are strong inhibitors of the aromatase enzyme working as a natural estrogen blocker. In a 2006 study, it had been proved in both mice and humans (11).

As grape seed extract has been biologically found to reduce the estrogen level by blocking its production, it has been used in various estrogen blockers as an active ingredient.

DIM (Diindolylmethane)

Apart from the above-mentioned natural estrogen blockers, one compound that needs special mention is Diindolylmethane, also known as DIM.

Cruciferous vegetables such as cabbage, broccoli, Brussel sprouts, kale, and cauliflower contain a compound called indole-3-carbinol (12). This compound on being metabolized upon digestion is converted into diindolylmethane (DIM).

DIM is known for supporting healthy hormone levels in both men and women. In women, it favorably influences the ratio of estrogen metabolites while in men, it helps reduce the conversion of testosterone to estrogen. DIM contributes to a better metabolism in the most natural way possible by working with our own hormones and adjusting their action to avoid hormonal imbalance.

How Does DIM Work As An Estrogen Blocker?

 DIM has three main benefits:

  • Makes estrogen metabolize down good estrogen pathway
  • Frees up bound testosterone
  • Acts as a natural aromatase inhibitor

The connection between DIM and estrogen is due to their molecular similarities. In order to be able to be used in the body, estrogen needs to be metabolized. It can do so by two metabolic pathways that estrogen can follow. It can either create good estrogen or can create bad estrogen.

As DIM uses the same metabolic pathway which is similar to that of good estrogen, supplementing the diet with DIM or eating cruciferous vegetables increases the chance for estrogen to be broken down into its beneficial form manifold.

To sum it up all, DIM facilitates the pathway that leads to “good” estrogen production and healthy hormone balance. An active metabolism of estrogen in the “good” direction automatically pulls unmetabolized estrogen away from the “bad” pathway, actually lowering the production and levels of these harmful estrogens.

DIM supports testosterone by helping it to maintain active and free testosterone. DIM can naturally be used as an estrogen blocker (13).

Pharmacological Estrogen Blockers

Some pharmaceutical products have an estrogen-blocking effect on men. Testosterone boosters may lead to sterility but there are some estrogen blockers like Clomid, that can restore hormone balance without affecting fertility.

Medications known as selective estrogen receptor modulators (SERMs) may also be used to block estrogen in men (14). They are marketed for breast cancer treatment. They can also be used to avoid the negative impact of high estrogen.

Some medications which are off label prescription drugs are also available in the market. Some of them are aromatase inhibitors which inhibit the enzyme aromatase from working and stop the conversion of testosterone to estrogen. This drops the estrogen level.

Foods That Can Reduce Estrogen In Blood

Food Sources with DIM

Foods that have shown tremendous potential in blocking completely or reducing the estrogen level when consumed are red grapes, mushrooms, flaxseeds, whole grains, and cruciferous vegetables like broccoli, cabbage, cauliflower, and kale (15).

These are all, a very good source of DIM thereby displaying the ability to block the activity of estrogen on the estrogen-sensitive receptors.

Low-Calorie Foods

Fat cells produce endogenous estrogen, so reducing the intake of calorie-rich food and reducing weight in people who are obese will work efficiently in that regard as well.

Most of the studies have been conducted on women that are related to dietary choices and estrogen level (16). But, there is a high possibility that it can be true for men as well.

Foods Low in Unsaturated Fats

In one study that was conducted in premenopausal and postmenopausal women, it was reported that the intake of dietary fat at a high level, mostly saturated fat directly affected the level of estrogen in the blood (17).

Higher the level of fat intake higher was the estrogen production in the body. Based on these studies, it is better to keep your saturated fat intake to a minimum level. It is better to avoid food which is very high in these fats.

It is always better to have lean meat, fish which are very high in omega-3-fatty acids and low in saturated fat.

Fiber-Rich Food

Several studies have also concluded that the inclusion of fiber-rich vegetables and fruits in diet results in a lower level of estrogen (17). This was shown amongst vegetarian postmenopausal female and non-vegetarian postmenopausal women.

In another study, it was found that a high fiber diet could block estrogen production in the body and reduce the risk of breast cancer and endometrial cancer (18). Studies have linked the high amount of estrogen in the blood with these cancers.

The 6 Main Benefits Of Estrogen Blockers

Estrogen Blockers may Decrease Body Fat in Men

Fit sportsman measuring body fat with caliper

There are several mechanisms through which estrogen regulates body weight in men. Estrogen plays a critical role in the regulation of appetite, energy expenditure, and body weight (19). Estradiol ( the major estrogen) is recognized as a regulator of food intake as well as energy expenditure in females.

Even though most works are focussed on females, considerable evidence supports a parallel role for estradiol in males as well. Low estrogen level has shown to increase leptin sensitivity resulting in inhibiting hunger triggers and regulate energy balance. Leptin is also known as the satiety hormone which inhibits hunger when the body does not need energy.

High estrogen levels will cause fat accumulation in men. This is the fat that is mainly accumulated in the abdomen. Fat cells produce estrogen as well that in turn will increase more endogenous estrogen production. To stop this cycle, estrogen blockers are the right solution. Lowering estrogen levels translates to lower abdominal fat.

Summary: Estrogen blockers, which lower estrogen in the body, increases leptin sensitivity resulting in the inhibition of hunger. This reduces the overall calorie intake resulting in decreasing body fat.

Estrogen Blockers May Increase Muscle Strength

muscular man from behind

Protein synthesis is the process that enables your body to grow strong and have bigger muscles (20). Estrogen blockers reduce the estrogen level and increase the testosterone level.

This aids in protein synthesis and helps in growing muscle fibers. Testosterone also repairs the muscle fibers that experience breakage due to vigorous exercise.

Bodybuilders and performance athletes also take them to increase the level of testosterone resulting in an increase in muscle mass, strength, and performance.

Summary: By lowering the estrogen level and indirectly increasing the testosterone level, estrogen blockers aid in protein synthesis, thereby increasing muscle strength.

They May Improve Libido

A lot of men experience low libido and erectile dysfunction when their testosterone level reduces.

Studies infer that if the reduction of testosterone is the cause of it, then the increase of testosterone should act as a remedy for the problem (21).

Hence, estrogen blockers which lower the estrogen level and in turn increase the testosterone level are one of the most critical solutions.

Summary: As high estrogen in men can cause loss of libido and erectile dysfunction, estrogen blockers may help resolve these issues by lowering estrogen levels.

They May Improve Cognitive Performance

It has been proved that men with high testosterone and low estrogen level perform better on cognitive tests compared to men with low testosterone and high estrogen.

One study suggests that cognitive abilities could be enhanced in older men who keep their testosterone levels high and their estrogen levels low. The study, published in 1999 by researchers at the University of California San Diego, looked at testosterone and estrogen levels among a group of over 500 men aged 59 and up (22).

The men had standard blood tests done to check their hormone levels, then underwent a series of tests of cognitive ability, including tests for memory, visual reasoning, and overall mental state. It was seen that men with higher testosterone ticked all the above-mentioned boxes as compared to the ones with the lower levels.

Summary: Studies have shown that cognitive abilities could be enhanced, in older men, by improving their testosterone levels and lowering estrogen levels.

Estrogen Blockers May Help In Treating Gynecomastia

Gynecomastia is the abnormal enlargement of breast tissue in males. It can impact one or both breasts. The imbalance between estrogen and testosterone is the main cause (23).

When the estrogen level in men increases the normal limit, it results in an increase in the amount of breast gland tissue. This results in enlarged breasts in men.

It can be controlled and treated with estrogen blockers. Estrogen blockers naturally increase the testosterone hormone that stops the formation.

Summary: Abnormal increase in estrogen results in enlarged breast tissue in males called gynecomastia. This can be treated by using estrogen blockers to reduce estrogen levels.

Estrogen Blockers May Help in Cancer

Even though most of the studies and usefulness of estrogen blockers have been studied on men, these blockers have been an integral part of hormone therapy that has been used to treat breast cancer in women.

About 2 out of 3 breast cancers are hormone receptor-positive. Their cells have receptors for the hormones estrogen (ER-positive cancers) and progesterone (PR-positive cancers) which help the cancer cells grow and spread.

There are several types of hormone therapy for breast cancer. Most types of hormone therapy either lower estrogen levels or stop estrogen from acting on breast cancer cells (24). Hence the use of estrogen blockers. These drugs work by stopping estrogen from fueling breast cancer cells to grow.

Summary: Estrogen blockers either lower estrogen levels or stop estrogen from acting on the breast cancer cells and inhibit their growth thus helping in the treatment of breast cancer in women.

Studies have suggested that 50-300 mg per day of DIM is effective for people who have cancer (25).

The grape seed extract recommendation is between 100 to 400 mg per day (26).

Other than that, the estrogen blockers that are available in the market have dosage recommendations in accordance with the ingredients in it, and abiding by them will ensure that you don’t go wrong at all.

The Side Effects Of Estrogen Blockers

Estrogen blockers directly affect the hormones, so the side effects are very similar to the menopause symptoms when there is a natural reduction of estrogen. They are hot flashes, mood swings, night sweat, osteoporosis, vaginal discharge, and vaginal dryness. Fortunately, the most effective estrogen-blocking supplements appear quite safe.

Studies have stated that commercial DIM supplements didn’t report any serious side effects even after six years of regular usage.

The grape seed extract usage in clinical research also observed that even after 14 weeks of its use, no major side effects have come up but you must not use any blood thinners like warfarin with it. Also if you are allergic to grapes, then, of course, it’s better to steer clear of it.

The safety profile of other estrogen blockers is less clear as they contain some ingredients which haven’t been studied so much. It is better to take the advice of your doctor before starting one.

Frequently Asked Questions

What Do Estrogen Blockers Do For Men?

Estrogen blockers reinstate the hormone balance of estrogen-testosterone in men and counteract the negative effects of high estrogen. Estrogen blockers work on combating the effect of high estrogens such as gynecomastia, low libido, erectile dysfunction and help in the decrease of body fat (27).

What Are The Most Effective Estrogen Blockers?

There are a lot of estrogen blockers that are flooding the market with its active ingredient and speedy results. The effective ingredients that we look for in them in accordance with their potency are ranked appropriately.

They are DIM, ginseng, aspartic acid, and grape seed extract. These ingredients all have several scientific research supporting their impact on modulating the body’s estrogen level.

The top rankers are DIM and grape seed extract though. Therefore, we should be certain to check on these ingredients before buying an estrogen blocker. Also, we must keep this in mind that basic vitamins and minerals like Vitamin D, zinc and magnesium which supports higher testosterone levels should be there in the estrogen blocker that we are buying.

Do Estrogen Blockers Help Build Muscles?

Yes, estrogen blockers do help build muscles. The decrease in estrogen increases the testosterone level which enhances muscle mass, performance, and strength.

With its positive effect on protein synthesis, it does help in muscle building. Along with testosterone boosters, estrogen blockers have been a favorite amongst bodybuilders and athletes (28).

Can You Get Estrogen Blockers Over The Counter?

Yes, estrogen blockers can be bought over the counter. These include vitamins, minerals, herbal compounds, and other supplemental molecules with the aim of a multi-effect focusing to bring down your body’s estrogen level.

There are certain chemicals that work as estrogen inhibitors but can be available only with a prescription from a doctor. They are normally used to treat medical conditions. They are more effective but may come with certain side effects which you should be cautious of.

The Final Note

Traditionally testosterone and estrogen have been considered to be male and female sex hormones. However, estradiol, which is the predominant form of estrogen plays an important role in male sexual function as well. Estradiol in men is essential for modulating libido, erectile function, gaining and maintaining bone mass and spermatogenesis.

But when estrogen increases and disrupts the delicate balance between testosterone and estrogen, supplements like estrogen blockers are used. They reduce too much estrogen in the body thereby averting the negative effects related to it.

Estrogen blockers can be natural ones like grape seed extract, wild nettle root, maca or can be compounds like DIM (diindolylmethane), which are chemicals that are found in cruciferous vegetables like broccoli, cabbage, cauliflower, and Brussel sprouts.

They can also be pharmaceutical Estrogen Blockers like Clomid, SERMS, or other aromatase inhibitors. Some of them are prescription drugs and some are available over the counter.

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