Fluoride: Risks, Uses, And Side Effects - Medical News Today

Maybe your like

Medical News TodaySubscribeWhat are the benefits, risks, and uses of fluoride?

Medically reviewed by Jennifer Archibald, DDS — Written by Yvette Brazier — Updated on July 14, 2025

Uses
Benefits
Risks
FAQ
Summary

Fluoride is found naturally in soil, water, and foods. It is also produced synthetically for use in drinking water, toothpaste, mouthwashes, and various chemical products.

Water authorities add fluoride to the municipal water supply because studies have shown that doing so in areas with low fluoride levels can reduce the prevalence of tooth decay in the local population.

Tooth decay is one of the most common health problems affecting children. Many people worldwide cannot afford the cost of regular dental checks, so adding fluoride can offer savings and benefits to those who need them.

However, concerns have arisen regarding fluoride’s effect on health, including problems with bones, teeth, and neurological development.

Fast facts about fluoride

Fluoride comes from fluorine, which is a common, natural, and abundant element.
Adding fluoride to the water supply reduces the incidence of tooth decay.
Fluoride protects teeth from decay by demineralization and remineralization.
Too much fluoride can lead to dental fluorosis or skeletal fluorosis, which can damage bones and joints.

Uses

Toothpaste and toothbrush — Asya Molochkova/Stocksy

Fluoride exists in many water supplies, and governments add it to drinking water in many countries.

It is also used in the following dental products:

toothpaste
cements and fillings
gels and mouthwashes
varnishes
some brands of floss
fluoride supplements, recommended in areas without fluoridation

Non-dental sources of fluoride include:

drugs containing perfluorinated compounds
food and beverages made with water that contains fluoride
pesticides
waterproof and stain-resistant items with PFCs

Excess fluoride exposure may come from:

fluoride in public drinking water
high concentrations of fluoride in natural fresh water
fluoridated mouthrinse or toothpaste
untested bottled water
inappropriate use of fluoride supplements
some foods

Not all fluoride exposure is due to adding the chemical to water and dental products.

Some geographical areas, such as southern Asia, eastern Brazil, and Africa, have drinking water that is naturally high in fluoride.

»MORE: What to know about fluoride in toothpaste. Learn more.

Benefits

The American Dental Association (ADA) says fluoride in water benefits communities because it:

reduces tooth decay
protects against cavities
is safe and effective
saves money on dental treatment
is natural

Fluoride is present in natural water. According to the ADA, adding fluoride is like fortifying milk with vitamin D, orange juice with calcium, or cereals with B vitamins and folic acid.

Studies continue to show that adding fluoride to water supports dental health.

A 2024 review states that adding fluoride to water is one of the greatest public health achievements of the 20th century, and is a highly effective way to strengthen teeth. It may reduce the risk of dental caries in adults by 27%.

Applying fluoride to children’s teeth can prevent or slow decay.

How does it work?

Fluoride prevents tooth decay by:

changing the structure of the developing enamel in children under the age of 7 years, so that it is more resistant to acid attack
providing an environment where better quality enamel forms, which is more resistant to acid attack
reducing the ability of bacteria in plaque to produce acid

This involves processes such as protection from demineralization, which is bacteria in the mouth combining with sugars to produce acid. This acid can erode tooth enamel and damage our teeth. Fluoride can protect teeth from demineralization that stems from the acid.

Another process is remineralization. If acid has already caused some damage to the teeth, fluoride accumulates in the demineralized areas and begins strengthening the enamel.

Who benefits the most?

Everyone can benefit from added dental protection, but those who can benefit particularly are people who:

enjoy snacking
have issues with dental hygiene
have little or no access to a dentist
follow diets that are high in sugars or carbohydrates
have had bridges, crowns, braces, and other restorative procedures
have a history of tooth decay or cavities

Most public health authorities and medical associations worldwide recommend that children and adults receive some fluoride to protect their teeth from decay.

Risks

Excessive exposure to fluoride may link to a number of health issues.

Dental fluorosis

Exposure to high concentrations of fluoride during childhood, when teeth are developing, can result in mild dental fluorosis. Tiny white streaks or specks will appear in the tooth’s enamel.

This does not affect the health of the teeth, but the discoloration may be noticeable.

Nursing infants or making up formula milk with fluoride-free water can help protect small children from fluorosis.

Children under the age of six should not use a mouthwash that contains fluoride unless directed by a dentist. An adult should also supervise children when brushing their teeth to ensure they do not swallow toothpaste.

Skeletal fluorosis

Excess exposure to fluoride can lead to a bone disease known as skeletal fluorosis. Over many years, this can result in pain and damage to bones and joints.

The bones may become hardened and less elastic, increasing the risk of fractures. If the bones thicken and bone tissue accumulates, this can contribute to impaired joint mobility.

Neurological problems

Exposure to fluoride could lead to issues with cognitive outcomes in the future.

A review by the National Toxicology Program (NTP) states findings of high levels of fluoride exposure linking to lower IQ in children, with children who consistently drank fluoridated water having a lower IQ score than those who did not.

The review considers all sources of fluoride however, not just from fluoridated drinking water. There is not enough data to determine whether the finding of lower IQs in children stems from the current level of fluoride in U.S. community water supplies.

More recent articles state that there is no negative association of fluoride with cognitive development, and previous studies do not take into account other factors such as socioeconomic status.

Overall, more research is necessary to prove cause and effect.

Fluoride poisoning

Acute, high level exposure to fluoride can lead to:

abdominal pain
excessive saliva
nausea and vomiting
seizures and muscle spasms

This will not result from drinking tap water. It is only likely to happen in cases of accidental contamination of drinking water, such as an industrial fire or explosion.

It is worth remembering that many substances are harmful in large quantities but helpful in small amounts.

Frequently asked questions

How much fluoride is recommended?

The Department of Health and Human Services (DHHS) sets the optimal level of fluoride for preventing tooth decay at 0.7 ppm, or 0.7 milligrams (mg) in every liter of water.The previous figure, in force from 1962 to 2015, was 0.7 to 1.2 ppm. In 2015, it was revised to the lower limit.The aim of this optimal level is to promote public health.

The Department of Health and Human Services (DHHS) sets the optimal level of fluoride for preventing tooth decay at 0.7 ppm, or 0.7 milligrams (mg) in every liter of water.

The previous figure, in force from 1962 to 2015, was 0.7 to 1.2 ppm. In 2015, it was revised to the lower limit.

The aim of this optimal level is to promote public health.

How much does the EPA allow?

The Environmental Protection Agency (EPA) aims to protect people from overexposure to toxic chemicals.It sets the maximum allowable level at 4 ppm and a secondary maximum level at 2 ppm. If levels are above 2 ppm, they are asked to inform the EPA. Levels above 4 ppm could be hazardous.In areas where water naturally contains higher levels of fluoride, community water systems must ensure that the maximum level is no higher than 4 ppm.

The Environmental Protection Agency (EPA) aims to protect people from overexposure to toxic chemicals.

It sets the maximum allowable level at 4 ppm and a secondary maximum level at 2 ppm. If levels are above 2 ppm, they are asked to inform the EPA. Levels above 4 ppm could be hazardous.

In areas where water naturally contains higher levels of fluoride, community water systems must ensure that the maximum level is no higher than 4 ppm.

Summary

Fluoride can prevent tooth issues such as decay and cavities. It is naturally present in water, but is also added synthetically for optimal community health.

As with any substance, excess intake or exposure can be harmful. It is important not to use any fluoride supplements without first speaking to a dentist.

Dentistry
Bones / Orthopedics
Environment / Water / Pollution

How we reviewed this article:

SourcesMedical News Today has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

Children's teeth. (2022).https://www.nhs.uk/live-well/healthy-teeth-and-gums/taking-care-of-childrens-teeth/
Community water fluoridation recommendations. (2024).https://www.cdc.gov/fluoridation/about/community-water-fluoridation-recommendations.html
EPA will expeditiously review new science on fluoride in drinking water. (2025).https://www.epa.gov/newsreleases/epa-will-expeditiously-review-new-science-fluoride-drinking-water
Fluoride exposure: Neurodevelopment and cognition. (2025).https://ntp.niehs.nih.gov/research/assessments/noncancer/completed/fluoride
Fluoride exposure and human health risks: A fact sheet from the IAOMT. (n.d.).https://files.iaomt.org/wp-content/uploads/IAOMT-Fact-Sheet-on-Fluoride-and-Human-Health.pdf
Fluoride in water. (n.d.).https://www.ada.org/resources/community-initiatives/fluoride-in-water
Fluorosis. (n.d.).https://www.mouthhealthy.org/all-topics-a-z/fluorosis/
Health effects: Fluoride & secondary hyperparathyroidism. (n.d.).https://www.toxicteeth.org/health/bone/fluorosis/hyperparathyroidism.html
Inadequate or excess fluoride. (n.d.).https://www.who.int/teams/environment-climate-change-and-health/chemical-safety-and-health/health-impacts/chemicals/inadequate-or-excess-fluoride
Murchio J, et al. (2022). Maintaining good oral health with fluoridated water.https://pmc.ncbi.nlm.nih.gov/articles/PMC8971694/
Nassar Y, et al. (2023). The role of fluoride on caries prevention.https://www.ncbi.nlm.nih.gov/books/NBK587342/
Podgorski J, et al. (2022). Global analysis and prediction of fluoride in groundwater.https://www.nature.com/articles/s41467-022-31940-x
Roberts A, et al. (2024). What’s in the water? Long-run effects of fluoridation on health and economic self-sufficiency.https://www.sciencedirect.com/science/article/abs/pii/S0167629624000791
Samaranayake L, et al. (2025). Facts and fallacies of the fluoride controversy: A contemporary perspective.https://www.sciencedirect.com/science/article/pii/S0020653925001224
Study finds early-life exposure to fluoride does not affect children’s brain development. (n.d.).https://adanews.ada.org/ada-news/2024/december/study-finds-early-life-exposure-to-fluoride-does-not-affect-children-s-brain-development/

Share this article

Medically reviewed by Jennifer Archibald, DDS — Written by Yvette Brazier — Updated on July 14, 2025

Latest news

AI model identifies biomarkers to predict prediabetes risk
Time-restricted eating: Study reveals best eating window for metabolism
AI-enhanced stethoscopes help to spot silent heart valve disease
Alzheimer's: Reading, writing, learning new languages may lower risk
Can brain training games actually reduce dementia risk? New study offers evidence

Related Coverage

What to know about fluoride in toothpasteMedically reviewed by Jennifer Archibald, DDS
This article examines what fluoride is, why producers add it to toothpaste, the benefits and risks of fluoride, and how to choose the best toothpaste
READ MORE
What happens when you remove fluoride from tap water?
Twelve years ago, Juneau, AK, stopped adding fluoride to community water sources. A newly published study looks at how this has affected its…
READ MORE
Everything you need to know about fluoride treatmentMedically reviewed by Jennifer Archibald, DDS
Fluoride treatment may offer benefits to those at risk of tooth decay. Natural health advocates, however, question the safety of fluoride. We look at…
READ MORE
What are the benefits and uses of Xylitol gum?Medically reviewed by Jennie Olopaade, PharmD, RPH
Some early research suggests that xylitol gum may help prevent cavities, treat gum disease, and have other health benefits. Learn more here.
READ MORE
How to know if you have a cavityMedically reviewed by Christine Frank, DDS
A cavity may cause white spots on the teeth, visible holes or gaps, or pain. This article explores how to know if you have a cavity and how to prevent…
READ MORE

Tag » What Does Flouride Do For Teeth

Health Conditions

Health Products

News

Original Series

Podcasts

General Health

Health Tools

Quizzes

About Medical News Today

Find Community

Follow Us