How Much Thyroid Damage Can Fluoride Actually Do?

Fluoride And Thyroid

You probably already know how important it is for your thyroid that you drink clean water every day. In many areas in the North America and other parts of the world the water that comes out of your tap is contaminated with harmful heavy metals, fluoride, xenoestrogens, petroleum chemicals, and even traces of prescription drugs that are in the water supply.

Unfortunately, buying bottled water can get expensive, but also creates an enormous amount of waste that fills our landfills unnecessarily.  Not only that, but bottled water can have residual amounts of harmful plastic-based chemicals in the water, most of which act as xenoestrogens in our bodies, disrupting proper hormone balance.

To solve this problem most people turn to water filters such as the Brita pitcher, but filters like that have been found to be lacking in the amount of chemicals that they can filter, but most importantly they don’t filter fluoride.


Buy water filterImage Credit: @anthonyphass

Why Filter Your Drinking Water When You Already Have Thyroid Problems

We know that hypothyroidism and Hashimoto’s disease can have many underlying causes and triggers that can be different from person-to-person. While paying attention to what you eat is one of the keys for improving your thyroid symptoms, you have to consider the impact from the environmental disruptors that can interfere with your thyroid function as well.

Taking into consideration that about 70% of American and 40% of Canadian water is fluoridated the chances that you have fluoride in your drinking water are very high. Fluoride is one of the environmental factors that can trigger a thyroid imbalance and you don’t want to miss it.

I’d like to share some facts how fluoride can negatively affect your thyroid and why you should be careful about your fluoride exposure especially if you already have hypothyroidism and Hashimoto’s.

5 Good Reasons To Remove Fluoride From Your Drinking Water

  1. Fluoride has the ability to act as an anti-thyroid drug

Fluoride can have anti-thyroid effects due to its ability to interfere with the use of iodine by your body and was once used as a treatment for hyperthyroidism. In fact, calcium fluoride preparations were successfully prescribed in the 1930s to treat patients with overactive thyroid to reduce their hyperthyroid symptoms.

An important thing to know is that a notably low dose of fluoride between 2 to 5 mg per day over several months is already sufficient to achieve a thyroid-suppressive effect. This dose is within the range of 1.6 to 6.6 mg per day of what people who live in the communities with fluoridated drinking water are now estimated to receive on a regular basis.

  1. Fluoride can cause hypothyroidism

Fluoride warning

This fact has been proven scientifically more than 150 years ago. It is reported that the dogs that were fed sodium fluoride developed an enlarged thyroid gland and developed hypothyroidism with time. Many studies that followed indicated a clear correlation between high fluoride areas and the incidence of goiter in people who lived there.

While excess fluoride in the water is associated with overt hypothyroidism, in others the hypothyroidism remains subclinical. These people may show thyroid hormones in the blood to be within normal values but TSH as mildly elevated.

Although these people can remain in the subclinical stage they already can have some common hypothyroid symptoms such as general tiredness, feeling cold and memory problems.

Depending on the amount and duration of fluoride exposure subclinical hypothyroidism can eventually develop to clinical hypothyroidism that will need active treatment. However, thyroid drugs won’t correct the underlying problem and may not be necessary after reducing fluoride exposure and thyroid function going back to normal.

Besides the thyroid too much fluoride can have other negative effects on your body and health. About 50% of fluoride that you ingest each day accumulates in your bones. With a long-term exposure you’re steadily increasing the fluoride levels in your bones over time. The initial symptoms of fluoride poisoning are arthritis-like symptoms such as joint pains.

From the foregoing, the link between areas with high fluoride in the water and hypothyroidism is obvious. Such links have been made more firm after many studies done in Russia and China have more recently been translated into English.

  1. Higher fluoride toxicity in the presence of iodine deficiency

The connection between low iodine levels and goiter has been known for a long time. This has been the case in poorer and less developed countries. Iodine is needed for the production of T3 and T4 and so its deficiency has far-reaching health effects that include poor growth and development in children.

If such a situation is coupled with high levels of fluoride intake in the water, then the hypothyroidism effect is compounded. Extensive studies done in China have proven that low iodine and high fluoride in the body increase chances of poor neurological development, low IQ and in severe cases can lead to mental retardation. These effects are more pronounced than when there is iodine deficiency alone.

This compounding fluoride effect can be explained by understanding the mechanism of the “halogen displacement” and how iodine, halogens, fluoride and bromide are chemically competing with each other.

The link between hypothyroidism and halogens competitiveness

Fluorine, iodine, chlorine and bromide all belong to the same group of elements called halogens and use the same receptor in the body. Fluoride has one additional electron to give it an extra charge. The chemical structures of fluorine, chlorine, bromine and fluoride are very similar to that of iodine and they compete with it blocking the iodine receptors in the thyroid gland.

If iodine is already deficient, the problem is complicated even more. For example, if your diet is deficient in iodine and you drink fluoridated water the iodine receptors in the thyroid could be filled up with fluoride.

This creates a situation whereby if fluoride levels are very high the binding power of iodine is greatly reduced because essentially all receptors are taken over by fluoride and block the uptake and utilization of iodine. Even if you’re getting enough iodine with your diet, you can’t use it.

  1. Fluoride can cause goiter

Goiter is a characteristic swelling or an enlargement of the thyroid and iodine deficiency can be one of the causes. Autoimmune Hashimoto’s and hypothyroidism of any origin can also cause this swelling. Vegetables of the brassica family are collectively referred to as goitrogens because they can trigger a goiter in people with iodine deficiency or insufficient iodine intake.

This is what the animal study in dogs that I mentioned before demonstrated very well and many other studies have proven it to this day.  Tests on how fluoride induce goiter were done in many countries by different scientists. In 1939 in South Africa, Steyn was able to prove that fluoride could induce a goiter. Interestingly the property of fluoride causing hypothyroidism became a court issue when in 1952, in the U.S, Reynolds Metal Corp battled it out with Paul Martin.

Another study was published in the Chinese Journal of Epidemiology and found out that the area of study had endemic fluorosis (effects of excessive fluoride in the water) and higher iodine. Despite this fact, goiter was still slightly prevalent. The researchers concluded that this could only be attributed to the high levels of fluoride in the water. Interestingly the values of T3, T4 and TSH were all normal.

The occurrence of goiter has also been found to be higher where there is high fluoride and low iodine. The toxic effects of high fluoride and the effects of low iodine synergistically worked to give rise to the higher rate of goiter.

  1. Fluoride can cause effects hypothyroidism-like effects to the unborn child of healthy women

Recent studies show that healthy women who are exposed to relatively low fluoride concentrations in the air and water during their pregnancy can accumulate fluoride in the placenta which acts as a natural protective barrier of the fetus.

The concentration of fluoride in the placenta of a mother using fluoridated water is higher than in women who drink water without fluoride and is approximately proportional to the intensity of pollution.

Fluoride levels in the blood of the fetus depend on maternal fluoride exposure. The use of fluoride supplements in the amount of 1.5 mg per day doubles fluoride blood concentrations in the unborn children.

In realization of these fluoride effects, the American regulatory body, FDA, banned the use of antenatal fluoride supplementation which was a common practice up to the 1960s. Today FDA clearly warns against the use of fluoride in pregnancy:

“The risks involved in use of the drug in pregnant women clearly outweigh potential benefits.”



Tap water

Image Credit: @gmo_gus

How To Reduce Fluoride Toxicity In Your Body

Fluoride is eliminated through the renal system. Small children retain up to 90% of ingested fluoride while adults retain about 60%.

5 Commonly used preparations for the detoxification of fluoride are:

  • Calcium
  • Magnesium
  • Boron which is given in measures of up to ¼ teaspoonful in a liter of water.
  • Vitamin C
  • Tamarind products have been used in Ayurvedic medicine to promote fluoride excretion through urine

Another way of reducing fluoride toxicity is to have adequate levels of iodine in the body. According to the The Handbook of Toxicity Compounds, Dr. Kenezy Gyula Korhaz suggest iodine as the best chelating agent for the removal of fluoride from the body.

In fact, iodine is the only chelating agent that can remove fluoride and bromide from the thyroid and other body tissues. When other halogens are high they can easily displace iodine if available in inadequate amounts.

According to Dr. Brownstein, in his book “Iodine, Why You Need It, Why You Can’t Live Without It” a single dose of iodine supplement can increase the excretion of fluoride from the body by up to 78%.

Does it mean that you have to supplement with iodine when you have iodine deficiency?

It may come as a surprise but you may not need the iodine supplements to correct iodine deficiency at all.

Here is why.

  • Supplementing with iodine can have negative effects if you have Hashimoto’s disease

Iodine supplements can stimulate the production and activity of TPO thyroid antibodies and intensify the autoimmune attack. As a result it can increase the damage to the thyroid gland and make you even more hypothyroid.

  • There is a fine line when it comes to how much iodine supplement to take

Both too much and too little iodine can impact the thyroid function. Most iodine supplements have too high dose of iodine in them and can throw off thyroid balance.

  • The main cause of iodine deficiency may not be the lack of iodine in your food

You are most likely getting enough iodine with our diet if you live in North America or any other industrialized country. However, if you are drinking fluoridated water there is a high probability that fluoride displaces iodine in your thyroid gland and other tissues creating iodine deficiency even if your get enough iodine with your diet.

Replacing missing iodine with iodine supplements not only doesn’t address the root cause of this imbalance which is fluoride toxicity, but also can have many negative effects especially if you already have been diagnosed with autoimmune Hashimoto’s or have a genetic predisposition to thyroid disease.

Start with removing the excess of iodine disruption by using a quality water filter that removes not only heavy metals, pesticides and other dangerous chemicals but also filters fluoride.

4 Steps To Correcting Iodine Deficiency Without Iodine Supplements

So before you reach to this iodine supplement bottle recommended in your supplement store or on the internet consider to do the following:

  1. Get tested for iodine deficiency using  Urine Iodine- Pre and Post Loading or Urine Iodine Test
  2. Get clear about your thyroid diagnosis and make sure if Hashimoto’s is indeed the cause of your hypothyroidism as it is in up to 90% of people with hypothyroidism
  3. Avoid fluoridated water as much as possible and make sure that dietary iodine intake is adequate.
  4. Getting a water filter that removes fluoride is a necessary step on your way to recovery from hypothyroidism and putting Hashimoto’s into remission.

Remember that some of the nasty chemicals found in your drinking water can not only negatively affect your thyroid function, make you hypothyroid and contribute to autoimmune Hashimoto’s symptoms but also be linked to bone disease, hip fractures, lower IQ…and even cancer in some cases.

P.S. Do you like what you read and want to get more? Get FREE eCourse Hypothyroidism Diet Guide



1.Effect of tamarind ingestion on fluoride excretion in humans. European Journal of Clinical Nutrition (2002) 56, 82-85.

2. Experiencé pour déterminer l’action des fluores sur l’economie animale.  Maumené E., 1854, Compt Rend Acad Sci (Paris) 39:538-539

3. Iodine, Why You Need It, Why You Can’t Live Without It by Dr. Brownstein

4. A preliminary approach to the relationship of both endemic goiter and fluorosis in the valley of Manasi River, Xin-Jiang to environmental geochemistry. Lin F, et al.,1986, Chinese Journal of Endemiology 5(1):53-55.

5. Research on the effects of fluoride on child intellectual development under different environmental conditions. Hong F, Cao Y, Yang D, Wang H. 2008. Fluoride 41(2)156-160.

6. The Handbook of Toxicity Compounds. Dr. Kenezy Gyula Korhaz, Seiler HG and Sigel, 1988.