In November 2024, President Donald Trump nominated Robert F. Kennedy Jr. to lead the US Department of Health and Human Services. He just had his confirmation hearing. Known for his anti-vaccine and anti-ultra-processed food views, RFK Jr. also stated that, under the Trump White House, he would work to remove fluoride from public water. 

“On January 20, the Trump White House will advise all US water systems to remove fluoride from public water,” RFK Jr. wrote on X. “Fluoride is an industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders and thyroid disease.”

Though January 20 has come and gone with no fluoride removal advisories from the Trump White House, RFK Jr.’s statement remains, leaving unanswered questions about fluoride and whether his claims are valid. 

What is fluoride, and why is it added to our water?

“Fluoride is the 13th most common element on earth,” the American Dental Association tells CNET in an email. “It occurs naturally in all water sources, such as springs, lakes, rivers, groundwater and seawater. The US Environmental Protection Agency labels anything that isn’t hydrogen or oxygen in water as a contaminant, such as magnesium, iron, calcium, fluoride and more. The EPA sets Maximum Contaminant Levels for all of these.”

The ADA also describes fluoride, a mineral, as “nature’s cavity fighter.” Aside from water sources, it can be found in rocks, soil and plants and, as a result, has made its way into our foods and beverages. You’ve likely also seen fluoride as an ingredient in dental products like toothpaste since it has been shown to strengthen tooth enamel (your tooth’s hard surface) and assist teeth in resisting decay (aka cavities). 

Cavities are caused by a disease called “caries,” which is five times more common than asthma and seven times more common than hayfever in people aged 5 to 17, per the ADA. Untreated cavities can cause pain that affects overall health and results in trouble sleeping, speaking, eating and paying attention at school or work. 

Since 1945, the US has added fluoride to its water supply as a cost-effective, equitable strategy to prevent cavities and improve oral health. The US Centers for Disease Control and Prevention named this fluoridation of drinking water one of the 10 great public health achievements of the 20th century. Now, three out of four Americans receive fluoride in their public drinking water, according to the American Cancer Society, which adds that the decision to incorporate fluoride into public water is made at the state or local level. 

On the financial side, the CDC states that communities of at least 1,000 people see an average estimated return on investment of $20 for every $1 spent on water fluoridation. On average, a person saves $32 each year by avoiding cavity treatment. Here, the organization cites a 2016 study, adding that the ROI for community water fluoridation will increase as the community size increases. 

The US Public Health Service currently recommends an optimal fluoride concentration in drinking water of 0.7 milligrams/liter. In a 55-gallon bucket, this is about three drops of water. However, this is not an enforceable standard. It is half of the World Health Organization’s 1.5 mg/L guideline. 

Also non-enforceable are the EPA’s National Secondary Drinking Water Regulations, which recommend that drinking water contain no more than 2.0 mg/L of fluoride. “EPA’s secondary maximum contaminant level (a non-enforceable standard) is set at 2.0 mg/L, which is recommended to protect children against tooth discoloration and/or pitting,” the EPA tells CNET in an email. What is enforceable is the EPA’s Primary Drinking Water Regulation, which is 4.0 mg/L for fluoride. “This level was set to prevent against increased risk of crippling skeletal fluorosis, a condition characterized by pain and tenderness of the major joints,” the EPA states.

Though community water systems are not required to comply with the secondary standard, the EPA does require that they notify customers within 12 months if fluoride levels are over 2.0 mg/L. If the fluoride level is above the primary standard, 4.0 mg/L, people must be notified within 30 days.

Which fluoride recommendation or regulation should be followed?

“The CDC recommendations are what should be followed for community water fluoridation and health benefits,” Dr. Susan Fisher-Owens, MD, MPH, an expert on oral health and American Academy of Pediatrics spokesperson, tells CNET in an email. “This level (0.7 mg/L, also sometimes referred to as parts per million) is the optimal level where there are the most benefits to people’s teeth with minimal risks.” She shares that other countries have similar community water fluoridation levels, like Canada (0.7 mg/L) and New Zealand (0.7-1 mg/L).

Fisher-Owens adds that the EPA’s standards are based on risk, with the primary standard (4 mg/L) being higher than we want in water. “The secondary standard (2 mg/L) is also above the ideal level, as determined by risk versus benefit, in that there is a greater likelihood of issues like spotting on teeth, without an increased benefit.” 

Is fluoride in drinking water safe?

“Studies continue to show that widespread community water fluoridation prevents cavities and saves money, both for families and the health care system,” reports the CDC, citing a 2007 study and 2015 study and concluding that fluoride in water reduces cavities by about 25% in children and adults. 

The ADA echoes the sentiment that fluoride in drinking water is “safe, effective and healthy.” The association states that thousands of studies, 70 years of research and the experience of 210 million Americans have led it to conclude that water fluoridation is “effective in preventing cavities and is safe for children and adults.” The AAP agrees. 

Since tooth decay can affect anyone throughout their lifespan, water fluoridation benefits people of all ages, per the AAP. Older adults, for instance, benefit because fluoridation prevents decay on teeth with exposed root surfaces, which affects older adults especially. 

“As a doctor, I think it is important to remind people that teeth are important to the rest of the body because tooth problems are associated with worse and more expensive overall health, including affecting pregnancy, diabetes, stroke, kidney disease, dementia and more,” states Fisher-Owens.

Is there a link between fluoridation of water and cancer?

“Many population-based studies have looked at the potential link between water fluoride levels and cancer,” writes the American Cancer Society. “Most of these have not found a strong link to cancer.” The organization explains that many of these studies have relied on factors that are difficult to control. For instance, in studies that compare different groups of people, their fluoride exposure and cancer rates, it’s impossible to prove that fluoride (and not other lifestyle factors) was the sole influence on cancer rates. 

There is also the question of how the type of fluoride, level of fluoride, amount of time exposed and age range during exposure increases one’s risk. 

The ACS states that when it comes to fluoride, much of the cancer concern appears to be around osteosarcoma, a rare type of bone cancer that typically develops in bone growth plates. The popular theory is that since fluoride tends to collect in the bone’s growth plates, the fluoride might cause the growth plate cells to grow faster and cause cancer. 

Because only about 500 osteosarcomas are diagnosed in US children and teens each year, it can be challenging to conduct large studies that can pick up on smaller differences in cancer rates between groups. “Smaller studies can usually detect big differences in cancer rates between two groups, but they might not be able to detect small differences,” explains the American Cancer Society. “If fluoride increased the risk only slightly, it might not be picked up by these types of studies.”

A 2025 systematic review concluded, “No clear link between fluoride and primary bone cancers found in 12 of 14 studies … No consistent links were observed across age, sex or fluoride levels.” The review also states that most studies were of low quality, so results should be interpreted cautiously. More high-quality research is needed. 

Children’s IQ and neurodevelopment 

In an August 2024 systematic review of published scientific material on fluoride exposure from all sources (not just drinking water) and neurodevelopment and cognition, the National Toxicology Program “concluded, with moderate confidence, that higher levels of fluoride exposure, such as drinking water containing more than 1.5 milligrams of fluoride per liter, are associated with lower IQ in children.” However, this is almost double the amount of 0.7 mg/L, the optimal fluoride guideline for US community water. The review was also primarily based on studies in non-US countries.

“It is important to note that there were insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for US community water supplies has a negative effect on children’s IQ,” wrote the NTP. “The NTP found no evidence that fluoride exposure had adverse effects on adult cognition.”

Considering the current research and statements published by multiple health organizations, the United States recommended fluoride level of 0.7 mg/L is considered safe. However, the NTP stated that, as of April 2020, community water systems supplying water with 1.5 mg/L or more of naturally occurring fluoride affected 0.59% of the US population (about 1.9 million people), while systems supplying water with 2 mg/L or more of naturally occurring fluoride served 0.31% of the US population (about 1 million people). Collectively, that’s 2.9 million people or 0.9% of the US population.

“No water supply in the US fluoridates (or has ever fluoridated) at these levels,” the ADA tells CNET, referring to the EPA’s Primary and Secondly Maximum Contaminant Levels. “The MCLs are set for areas in the country that have high naturally occurring levels of fluoride, mostly seen in the western US. This impacts only 0.31% of the country.” The latter reiterates the NTP’s finding for systems supplying water with 2 mg/L or more of naturally occurring fluoride. 

Skeletal fluorosis 

“Long-term exposure to excessively high levels of fluoride can cause skeletal fluorosis, which causes pain and damage to bones and joints,” wrote Webster-Cyriaque. “Skeletal fluorosis is extremely rare in the US and there is no evidence that it is caused by the recommended level of fluoride in public tap water.” 

The American Cancer Society confirms that if someone is exposed to fluoride levels higher than the EPA’s primary drinking water standard of 4.0 mg/L for a long period of time, it can cause skeletal fluorosis. 

How widespread is fluoridation in the US? Which states have it? 

The CDC notes that implementing water fluoridation is decided by state and local governments, and voters are often the ones who decide to adjust water fluoride levels. “Some states have laws that require water systems of a certain size to provide fluoridated water,” reports the CDC. “In some areas, the level of naturally occurring fluoride in water is already at a level proven to prevent cavities.”

Since community water systems regularly test public water to comply with regulations and industry standards, fluoride content can be adjusted to reach the optimal level of 0.7 milligrams/liter. The CDC recommends that these fluoride level measurements be conducted daily and verified monthly by an independent state-certified lab.

The fluoride level results are then uploaded into the Water Fluoridation Reporting System, which the public can access to see fluoride levels in their area. However, providing this information is voluntary, and not all states participate. To learn more about if there is fluoride in your drinking water (and at what levels), you should contact your community’s water provider. If you aren’t sure about your water source, ask your dentist, doctor or local health department about getting your water tested for its fluoride level. 

What if there is too much or too little fluoride in your water?

“Well water can be above the recommended level because fluoride is naturally in rock, and therefore naturally in water. It just isn’t controlled as well as community water fluoridation,” Fisher-Owens tells CNET. “If the fluoride level in the water is too high, people should look for another source of water if possible. If their water has too little fluoride, children can get prescribed fluoride tablets. Adults can get them, too, depending on health conditions that make them more at risk for problems with their teeth.”

To help with low fluoride levels, dentists and some pediatric doctors can also apply fluoride from visit to visit, according to Fisher-Owens. “And, of course, this is on top of brushing twice a day with a small amount of fluoridated toothpaste and trying to reduce/eliminate drinking sugar-sweetened beverages and frequent high carbohydrate snacks.”

Fisher-Owens adds that you can test your water with a commercial test kit or find out if any community programs in your area offer them. The ADA tells CNET that the EPA recommends checking your well water for all major contaminants (anything that isn’t hydrogen or oxygen in water) every three years.

If your drinking water contains less than 0.7 mg/L of fluoride, the CDC advises that you speak to your dentist and, if you have a child, their pediatrician. They can help you decide if your child could benefit from fluoride toothpaste, mouthwash or supplements. 

For water that exceeds 2.0 mg/L of fluoride, the EPA recommends that children age 8 and under be given alternative drinking water sources. “Pregnant people or parents of children who live in areas with higher fluoride concentrations can use low-fluoride bottled water, for instance, to mix infant formula,” it adds.

Contact your public health department if your water’s fluoride level is 4.0 mg/L or more. You should consider using a filter that removes fluoride from drinking and cooking water. Since fluoride is not absorbed through the skin, you don’t have to worry about water used for bathing and cleaning. 

For those with a private water source, the CDC states that less than 1% of the US population has water from private wells or drinking systems with a fluoride level over 2.0 mg/L. The only way the level of fluoride can be found is through laboratory analysis, which your local health department can help you find. 

Are there water filters that remove fluoride?

“If water fluoride levels are too high, consider using bottled water for drinking and cooking,” wrote Jennifer Webster-Cyriaque, DDS, PhD, deputy director of the National Institute of Dental and Craniofacial Research. “You can also remove fluoride using a reverse osmosis filter system.”

The CDC states that reverse osmosis water filters remove certain chemicals from water, such as sodium, lead, chloride, copper and chromium. They may also decrease the amount of fluoride, magnesium, calcium, arsenic, sulfate, radium, potassium, phosphorus and nitrate. Check the product’s label to see the specific chemicals a water filter removes. 

To find out exactly what a water filter removes, the CDC specifically recommends looking out for an NSF certification on the label. The National Science Foundation is an independent federal agency that supports science and engineering in US states and territories. It has a database where you can look up reverse osmosis drinking water treatment systems that claim to reduce fluoride. In an email, the EPA also tells CNET that the Water Quality Association provides additional information on certified home water treatment units.

Notably, fluoride may be included under the total dissolved solids. TDS includes all organic and inorganic materials dissolved in water that are not H2O molecules. For the same reason, fluoride may also be called a contaminant along with magnesium, calcium, iron and more. 

According to Fisher-Owens, it’s also important to know that “RO filters reduce fluoride by up to 94%, depending on maintenance, including cleanliness of the filters and water pressure in the supply line.”

The EPA defines reverse osmosis as “the process by which pressure forces water through a semi-permeable membrane, creating a stream of treated water.” This type of filter can be costly to install and maintain, generate a large quantity of wastewater, remove beneficial minerals and may not remove all contaminants. 

The EPA recommends selecting a WaterSense-labeled filter to ensure you are wasting less water. Yet, no point-of-use reverse osmosis water treatment systems are listed with a WaterSense label. “In November 2024, EPA’s WaterSense Program released a specification to label point-of-use reverse osmosis systems,” the EPA tells CNET. “Manufacturers can apply to have their products certified to earn the WaterSense label.” In other words, the final specification was only recently published, so no point-of-use reverse osmosis systems have received the WaterSense label yet. 

Can you get rid of fluoride by boiling water?

“No. Boiled water does not remove fluoride from drinking water,” the EPA tells CNET.

Dr. Fisher-Owens agrees, adding, “In fact, boiling slightly increases the fluoride content by boiling off some water (in essence, concentrating the fluoride).” Reverse osmosis filters, on the other hand, can reduce fluoride by up to 94%. 

As for the American Dental Association, it tells CNET that boiling can remove viruses or bacteria, but not fluoride. It advises that fluoride can be filtered out with reverse osmosis filtration.

Is water fluoridation still necessary today?

The American Academy of Pediatrics states that water fluoridation remains critically important in its Campaign for Dental Health. Tooth decay affects over 90% of Americans by the time they become adults, which is especially significant considering that more than 100 million Americans lack dental insurance. 

The AAP adds that fluoridated water is the most inexpensive method of providing fluoride, considering that the per-person annual cost of fluoride rinse programs, fluoride supplements and fluoride varnishes is higher than that of providing fluoridated water. The per-person annual cost of fluoride supplements, in particular, is 70 times higher than fluoridated water. 

At what amount is fluoride considered toxic?

According to the ADA, the single dose of fluoride that could cause acute fluoride toxicity is 5 mg/kg of body weight (11mg/kg of body weight of sodium fluoride). However, it is impossible to get this dose of fluoride from water with fluoride at the optimal level. For a 155-pound adult man to experience acute fluoride toxicity, it would require him to drink almost 120 gallons (more than 1,900 eight-ounce glasses) at one time of water with a fluoride level of 0.7 mg/L. 

Should you be concerned about your child developing dental fluorosis? 

The American Dental Association describes dental fluorosis as “a change in the appearance of the tooth enamel that only occurs when younger children consume too much fluoride, from any source, over long periods when teeth are developing under the gums.” The CDC states that dental fluorosis can cause white flecks, spots or lines on the outer enamel layer. Often, a trained professional is needed to detect these changes (which occur until age 8, when the enamel is fully formed), and even so, the type of fluorosis in the US has no effect on tooth function and may make the teeth more resistant to decay.

The ADA also addresses whether it’s safe to use fluoridated water to reconstitute infant formula, stating that it is safe. “If your baby is primarily fed infant formula, using fluoridated water might increase the chance for mild enamel fluorosis, but enamel fluorosis does not affect the health of your child or the health of your child’s teeth,” states the ADA. The American Academy of Pediatrics also states that using fluoridated water to mix formula is safe, but there is a small risk of fluorosis. Most cases are mild, not painful and do not affect the health or function of the teeth. 

To decrease the chances that your child’s teeth will develop fluorosis, the ADA states that you can breastfeed your child, as nursing or pregnant people who consume fluoridated water “do not pass on significant amounts of fluoride to their child.” You can also use ready-to-feed formula, which contains little fluoride, or mix powdered or liquid concentrate formula with water that is fluoride-free or contains low concentrations of fluoride. This is often found in bottled waters labeled as purified, de-ionized, demineralized or distilled unless fluoride is listed explicitly as an added ingredient.

The FDA’s quality standard for fluoride in domestically packaged and imported bottled water is 0.7 mg/L, the same as the CDC’s guideline for drinking water. 

“Caregivers can reach out to a health care professional and can also check that fluoride levels in their drinking water are at the recommended level: 0.7 mg/L,” wrote Webster-Cyriaque. “Levels higher than 1.5 mg/L can increase the risk of dental fluorosis in children younger than 8.”

Ultimately, the ADA recommends consulting with your child’s doctor and dentist to determine what’s best for them. 

What about fluoride toothpaste and mouthwash?

The ADA states that getting the right amount of fluoride is best to decrease the risk of your child developing fluorosis before age 8. Since toothpaste and mouthwash can contribute to a child under 8 developing fluorosis in both non-fluoridated and fluoridated communities, the ADA provides the following recommendations: 

For children under age 3: Start brushing their teeth once they begin to come into the mouth using an amount of fluoride toothpaste no bigger than the size of a grain of rice. 

For children aged 3 to 6: Use no more than a pea-sized amount of fluoride toothpaste. 

In a 2019 report published by the CDC, the organization found that “40% of children aged 3–6 years used too much toothpaste.” Ensure your child is supervised when brushing their teeth, which should be twice a day or as directed by their dentist or doctor. The CDC also advises that children be supervised to make sure they are spitting out — not swallowing — toothpaste after brushing. 

Note that all toothpastes with the ADA Seal of Acceptance contain fluoride. In 2021, the World Health Organization added fluoride toothpaste to its list of essential medicines.  

The CDC states that fluoridated water and toothpaste work better together than alone to prevent cavities, so using both is beneficial. Fluoride toothpaste also provides a higher fluoride concentration at important times of the day, such as bedtime. 

Fluoride mouthwash and children

The ADA recommends that no child under 6 years old use mouthwash unless directed by a dentist. For those over age 6, the ADA mentioned that a Cochrane systematic review found regular use of fluoride mouthwash decreased tooth decay in children even if they were exposed to other fluoride sources. Nonetheless, you should always consult your dentist before changing your child’s oral health care routine. 

In general, the ADA reports that manufacturers producing fluoride mouthwash must demonstrate fluoride concentration and other parameters to ensure they comply with current guidelines.

Pregnant people and fluoride

In areas where fluoridated water exceeds the EPA-recommended level of 2.0 mg/L, the EPA recommends that pregnant people use low-fluoride bottled water. The ADA states that nursing or pregnant people who drink fluoridated water “do not pass on significant amounts of fluoride to their child.”

A National Institutes of Health’s Office of Dietary Supplements fact sheet on fluoride for health professionals reports that the Food and Nutrition Board’s daily tolerable upper intake level for fluoride is 10 mg for pregnant and lactating people ages 14 to 51. This is the maximum daily intake unlikely to cause adverse health effects.

In May 2024, the Keck School of Medicine of USC published the first US study of fluoride exposure during pregnancy, with 220 mother-child pairs participating. It found that women exposed to higher levels of fluoride during pregnancy tended to rate their 3-year-olds high on overall neurobehavioral problems and internalizing symptoms such as emotional reactivity, anxiety and somatic complaints. 

Specifically, a 0.68 mg/L increase in fluoride exposure was examined to nearly double the chance of a child showing neurobehavioral problems close to or within a range that meets clinical diagnosis criteria.

“While this is the first US-based study of fluoride exposure during pregnancy, more studies are urgently needed to understand and mitigate the impacts in the entire US population,” said Ashley Malin, PhD, an assistant professor of epidemiology at the University of Florida and lead author of the study. 

When discussing evidence suggesting that higher fluoride intakes during early development may be connected to lower IQ and cognitive impairments in children, the National Institutes of Health states that many experts “consider this evidence to be weak and methodologically flawed” and that additional research is warranted. This assessment does not specifically address the Keck School of Medicine of USC study, but the fact sheet was last updated on June 26, 2024, which is after the study was published on May 20, 2024. 

When asked about this study, Fisher-Owens states, “I respect colleagues from USC, but in this study, they use spot measurements of fluoride instead of 24-hour urine samples; spot urines can vary a lot on the same person throughout the day, so it’s less reliable to use in a study. Also, they did not statistically ‘control’ for actual tap water consumption or other factors that could be associated with changes in neurobehavior.” 

Fisher-Owens explains that there is ongoing research on this topic, but in the meantime, “We know from other research that having healthy teeth and mouth during pregnancy can help decrease chances of premature and low birth weight babies.” She adds that pregnant people can be more at risk for certain oral health problems — due to increased snacking and vomiting along with hormonal changes — especially since some pregnant people may be afraid to get dental care during pregnancy. However, Fisher-Owens states that it is safe. 

According to the ADA, after reviewing the USC study, numerous medical experts found it lacking in scientific credibility. “The researchers examined only a small homogenous group of mothers (low-income, urban Hispanic women) and used only one measurement of mothers’ fluoride intake (urinary fluoride) during pregnancy,” the association tells CNET. “Other researchers have noted that this is not a reliable indicator of fluoride intake.”

The ADA goes on to state that the USC study did not examine children’s intake of fluoride, lead or arsenic and did not look at social measures that can influence a child’s IQ and behavior, including poverty, parents’ IQ and caretakers’ educational level. The association concluded by saying that medical experts from the American Academy of Pediatrics and the American College of Obstetrics and Gynecology did not think this was a credible study.

When asked about this study, the EPA states, “EPA has not reviewed this new study. However, the Safe Drinking Water Act requires the EPA to review each national primary drinking water regulation at least once every six years and revise them, if appropriate. The Agency will consider new peer-reviewed science in future assessments of fluoride in drinking water.”

Should pregnant people drink bottled water? 

According to the American Academy of Pediatrics, “Unless there are concerns about tap water contamination, bottled water is not preferred to tap water during pregnancy.” The academy adds that the fluoride amount is not required to be listed on bottled water labels unless the manufacturer makes a claim about the product’s fluoride content. 

Dr. Fisher-Owens explains that bottled water is not regulated as precisely as community drinking water fluoridation. There may also be contaminants in the bottled water that provide no benefits. 

“Pregnant people should do their best to eat healthy, brush their teeth and check with their perinatal providers on what is best for their circumstances,” advises Dr. Fisher-Owens. 

What foods is fluoride in?

“Most of the fluoride that people consume comes from fluoridated water, foods and beverages prepared with fluoridated water, and toothpaste and other dental products containing fluoride,” explains the National Institutes of Health’s Office of Dietary Supplements. 

Because tea plants intake fluoride from soil, brewed tea usually contains higher levels of fluoride than most foods. This depends on the tea type and source. In brewed tea made with distilled water, fluoride levels can range from 0.3 to 6.5 mg/L. 

The National Institutes of Health lists the following after brewed tea, in order of having the most milligrams per serving of fluoride to the least:

• Coffee, brewed
• Shrimp, canned
• Bottled water with added fluoride
• Raisins
• Oatmeal, cooked
• Grapefruit juice
• Potatoes, russet, baked
• Rice, cooked
• Cottage cheese
• Pork chop, baked
• Yogurt, plain, low-fat
• Lambchop, cooked

These are only a few examples, for which you can find the fluoride content amount here. The amount of fluoride present in food and beverages may vary based on the fluoride levels in the water used for preparation. 

The bottom line 

The US Centers for Disease Control and Prevention, American Dental Association and American Academy of Pediatrics consider the US Public Health Service’s recommended 0.7 mg/L of fluoride in drinking water safe. To see the fluoride level in your water system, check the Water Fluoridation Reporting System, call your water provider or have your water tested. If fluoride is above the recommended amount, consider using a reverse osmosis filter or bottled water that is purified, de-ionized, demineralized or distilled in which fluoride is not explicitly listed as an added ingredient. If it is below the recommended amount, consult your dentist or doctor for advice. 

If you have any additional questions specific to your or your child’s health, your best bet is to consult your doctor, dentist or pediatrician.