Can fluoride make you sick?

There is a lot of misinformation circulating about water fluoridation and fluoride use in dental care products. Some opponent groups claim that fluoride can make you sick by causing a range of serious health issues. But what does the science actually say about fluoride safety and health risks?

First, studies show that fluoride can make you sick, especially if it is ingested in excessive amounts. Acute fluoride toxicity, caused by the accidental ingestion of fluoride-containing substances, can lead to symptoms such as nausea, vomiting, abdominal pain, weakness, muscle spasms, and in severe cases, cardiac issues and even death. 

Chronic toxicity can also occur with prolonged exposure to elevated levels of fluoride, leading to various health effects, although these are often influenced by factors such as dose, duration of exposure, nutritional status, and interactions with other elements. 

Therefore, while fluoride in appropriate amounts is beneficial for dental health, excessive exposure can indeed make you sick.

That said, let’s evaluate some common claims about fluoride causing illness and analyze what current research indicates. Getting the facts straight on fluoride helps patients make informed choices regarding oral health.

Can fluoride make you sick

Fluoride Toxicity: Can it Make you Sick?

Excessive ingestion of fluoride, primarily from oral hygiene products like toothpaste, mouthwashes, and supplements, can lead to harmful effects, especially in children below the age of 6. Fluoride toxicity often occurs because young children tend to swallow flavored toothpaste, which contains fluoride. Even natural alternatives like chewing sticks (miswak) are safer.

The toxic effects of fluoride include:

  • The formation of hydrofluoric acid upon contact with moisture, causing tissue burns due to its low pH.
  • Fluoride also inhibits nerve impulses and enzyme functioning, leading to physiological disruptions.
  • Imbalances in electrolytes like calcium and potassium can disturb cardiac rhythm.
  • Furthermore, excessive fluoride can react with oxygen, disrupting metabolism and producing harmful substances like hydrogen peroxide and free radicals, which affect antioxidants.

It’s crucial to use fluoride-containing products cautiously, especially with young children, and follow recommended doses to prevent these toxic effects.

Symptoms of Acute and Chronic Fluoride Toxicity

a. Acute Toxicity


Accidental ingestion of fluoride solution or salts mistaken for edible substances.



  • Nausea
  • Vomiting (sometimes with blood)
  • Abdominal pain
  • Diarrhea
  • Weakness
  • Hypocalcemia (low calcium levels)
  • Muscle spasms (especially in hands and feet)
  • Hypotension
  • Bronchospasm
  • Dilated pupils
  • Hyperka
  • Lemia (high potassium levels).

Severe cases may lead to ventricular arrhythmias, cardiac arrest, and even death.


Some individuals may experience excessive urination resembling diabetes insipidus, potentially persisting for days to months.


Acute polyuric renal failure, metabolic and respiratory acidosis, coma, convulsions, leading to death.

b. Chronic Toxicity:


Chronic fluoride toxicity is more prevalent than acute toxicity.


Effects depend on duration, dose, nutritional status, renal function, and interactions with other trace elements.


Acute toxicity can be fatal and often results from accidental ingestion of substances containing high levels of fluoride, while chronic toxicity, usually resulting from prolonged exposure to lower levels, has various effects influenced by several factors.

Fluoride Toxicity

Source: Potential fluoride toxicity from oral medicaments: A review

Supposed Adverse Effects of Fluoride


Claim: Fluoride causes dental and skeletal fluorosis resulting in brittle bones and teeth.

Facts: Fluorosis (overexposure to fluoride) only occurs in developing teeth and bones with prolonged high doses. Water fluoridation and dental products do not provide fluoride levels high enough to cause fluorosis when used properly. Mild dental fluorosis can result in faint white speckling of tooth enamel that is mostly a cosmetic effect. Most claims of skeletal fluorosis turned out to be cases of misdiagnosed osteoporosis or arthritis upon expert review.

Thyroid Disease

Claim: Fluoride is an endocrine disruptor causing hypothyroidism.

Facts: While high doses of fluoride can suppress thyroid function, there is no evidence that appropriate fluoride exposure through dental products and fluoridated water impacts healthy thyroid function at safe levels. Quality reviews find fluoride does not appear to meaningfully alter thyroid hormone levels at recommended dosages.


Claim: Fluoride is a neurotoxin linked to lower IQ.

Facts: A few controversial studies found a weak association between high water fluoride levels of 5+ ppm and slightly lower IQ scores. However, these had significant methodology flaws. Hundreds of reputable studies find no impact on IQ or neurological development at optimal fluoride levels of 0.7 ppm in drinking water and below. The evidence overwhelmingly affirms fluoridation’s safety.


Claim: Fluoride causes bone and other cancers.

Facts: No reputable studies show definitive links between fluoride exposure at safe levels and increased cancer risk. The largest research reviews have found no clear associations between fluoridated water or dental fluoride use and cancer. The evidence does not support assertions that fluoride causes cancer.

Final Thoughts

Overall, the vast body of quality scientific evidence reaffirms fluoride is safe when used appropriately in water fluoridation and dental products. Fluoride does not make you sick and claims that it causes serious disease lack convincing data when proper exposure levels are maintained.

While it’s wise to look at both potential risks and benefits when evaluating health products, bold claims that fluoride makes you sick at recommended exposure levels do not stand up to scientific scrutiny. Quality reviews continue to confirm fluoridated water and dental fluoride use are safe and provide immense protection against tooth decay when used properly. The safety data should reassure patients that fluoride remains one of dentistry’s most important preventive tools.




  • Editorial team

    A team comprising oral health care professionals, researchers, and professional Writers, striving to impart you with the knowledge to improve your oral health, and that of your loved ones. 

  • Lilly

    Lilly, aka, Liza Lee, is a passionate community oral health officer and our lead writer. She's not only well-versed in performing a multitude of dental procedures, including preventive, restorative, and cosmetic, but also an avid writer. Driven by the significant oral health burden all around her, Lilly strives to build capacity and promote oral health. She envisions making a lasting impact by advancing research, prevention, and promotion efforts to alleviate oral health disparities. Please share your views and opinions on my posts.

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