Fluoride is a naturally occurring mineral in water. Decades of scientific research have repeatedly demonstrated that measured levels of fluoride in water are safe and prevent tooth decay. Fluoride has recently been in the news as several states are considering banning it based on common misrepresentations. Much like anything, an overabundance of fluoride can be harmful; however, the fluoride levels in our water supply are safe and provide a positive benefit to society. For low-income communities, fluoridated drinking water may be the only preventive care available for their oral health. Fluoride is a simple and effective public health measure that has shown great value to children’s health. It promotes healthy teeth, which promotes healthy individuals, which increases community well-being, and saves everyone money.

Herein we outline the benefits of fluoride, recommended safe levels, and then address common misconceptions.

Fluoride occurs naturally in drinking water, as it is absorbed as water runs over fluoride-rich rocks. The amount of fluoride varies based on geographic location. The recommendation to add fluoride in drinking water was made because studies showed a significant decrease in the number of children with tooth decay after they drank naturally occurring water that was rich in fluoride.

Based on these scientific studies showing, in 1945, Michigan was the first state to begin water fluoridation. This public health effort has been supported by scientific research and health organizations like the U.S. Surgeon General and the National Institute of Dental and Craniofacial Research. The United States Public Health Service (USPHS) has recommended fluoride in drinking water since 1962 to prevent tooth decay. Water fluoridation benefits over 200 million Americans and prevents about 25% of tooth decay in children and adults.

Cities that had fluoride in their water supply and removed it have witnessed an increase in tooth decay among children. For example, in Alberta, Canada and Juneau, Alaska, researchers found that ceasing the use of fluoride in their water supply consequently resulted in an uptick of tooth decay among children. Removing fluoride from drinking water exacerbates health disparities. An Australian study examined a decision made in 2012 to stop the use of fluoridated water. Using an index to measure socioeconomic advantages and disadvantages, the researchers found that lower-income areas were more prone to having less access to fluoridated water–thus, increasing the likelihood of developing dental disease.

The USPHS has set the recommended level of fluoride for drinking water at 0.7 milligrams per liter (mg/L). According to the Centers for Disease Control and Prevention (CDC), this equates to three drops in a fifty-five-gallon barrel. Since fluoride in water is naturally occurring, it is impossible for water suppliers and people who drink well-water to keep to an exact number. Thus, the Environmental Protection Agency (EPA), has set the acceptable range for fluoride to 0.7 mg/L to 2.0 mg/L.

In 1996, Congress amended the Safe Drinking Water Act to require an annual report about water quality in each US county. If you wish to know the concentration in your local supply, please contact your water supplier and ask how much fluoride is in your water.

What about Toothpaste?

Toothpaste contains higher levels of fluoride than drinking water. This is because people should not swallow and instead should spit-out their toothpaste after brushing. Toothpaste for children often contains no, or reduced amounts, of fluoride, because they are more apt to swallow it.

Everything in moderation. Fluoride, like any other element exceeding the recommended amount, poses an adverse effect on human health. Several studies have demonstrated what can happen when people far exceed the recommended amounts. Science is clear that fluoride, when used at the recommended levels, is safe.

A 1990 study by the National Toxicology Program sparked a debate on whether fluoride causes cancer. This study on rats found greater bone tumor growth in rats given water with high levels of fluoride. In response, the USPHS reviewed over fifty epidemiologic studies spanning over forty years and concluded that fluoridated water did not serve as a cancer risk to people. Further comprehensive studies, including ones in 1993, 1999, and 2011 also found no link between fluoridization and cancer.

The pineal gland, also called the sleep gland, sits outside of the blood-brain barrier, and is exposed to systemic concentrations of fluoride. Some people believe fluoride calcifies the pineal gland and detriments sleep and thyroid function. It is true that fluoride easily converts to calcium. Thus far, studies have been inconclusive about the impact of fluoride on pineal gland calcification. Currently, the possible negative impact on sleep is far outweighed by the positive benefits on oral health.

Some studies have raised concerns that fluoride exposure can lead to reduced cognition (IQ levels). In a meta-analysis conducted in 2023, researchers found that “fluoride exposure at the concentration used in community water fluoridation is not associated with lower IQ scores.” In this study, the researchers divided the studies into those that tested impacts at high levels (well above USPHS, CDC, EPA recommended levels) of exposure versus low levels of exposure. The only studies that show a link between reduced IQ and fluoride were those that administered fluoride at levels above the recommended levels. Additionally, other variables, such as environmental exposures and socioeconomic status (SES), variables that can also have a negative impact on IQ, were not properly considered.

The U.S. EPA regulates what concentrations of fluoride are acceptable for drinking water and community water systems are required to monitor fluoride levels regularly to ensure compliance with EPA standards. This monitoring also enables cities to create annual reports on water quality in compliance with the Safe Drinking Water Act.  The CDC also provides tools like the Water Fluoridation Reporting System (WFRS) to help states manage and monitor fluoridation quality. If fluoride exceeds the maximum level, the water system must notify people within 30 days of discovering the violation.

Fluoride in water is a safe, effective, and simple public health measure. It increases oral health. Poor oral health can result in an inability to concentrate and missed school days, this causes poorer school outcomes, which, in turn, leads to a negative impact on society. In many lower-income communities, fluoride in water is the only dental care people receive. Water providers are required by law to monitor fluoride levels to ensure compliance with regulated safe levels.

1. American Cancer Society. (2022, November 18). Water Fluoridation and Cancer Risk. February 20, 2025. 
2. Archer NP, Napier TS, Villanacci JF. Fluoride exposure in public drinking water and childhood and adolescent osteosarcoma in Texas. Cancer Causes & Control2016; 27(7):863–868. [PubMed Abstract]
3. Blakey K, Feltbower RG, Parslow RC, et al. Is fluoride a risk factor for bone cancer? Small area analysis of osteosarcoma and Ewing sarcoma diagnosed among 0–49-year-olds in Great Britain, 1980–2005. International Journal of Epidemiology2014; 43(1):224–234. [PubMed Abstract]
4. Bucher JR, Hejtmancik MR, Toft JD, et al. Results and conclusions of the National Toxicology Program’s rodent carcinogenicity studies with sodium fluoride. International Journal of Cancer1991; 48(5):733–737 
5. Centers for Disease Control and Prevention. Achievements in public health, 1900–1999: fluoridation of drinking water to prevent dental caries. Morbidity and Mortality Weekly Report1999; 48(41):933–940.
6. Centers for Disease Control and Prevention. (2024a, May 24). About Community Water Fluoridation. Accessed March 3, 2025. 
7. Centers for Disease Control and Prevention. CDC Scientific Statement on Community Water Fluoridation. (2024b, May). February 20, 2025. 
8. Centers for Disease Control and Prevention. (2024c, May 15). Community Water Fluoridation Frequently Asked Questions. April 3, 2023. 
9. Centers for Disease Control and Prevention. (2024d, May 15). Water Fluoridation Data and Statistics. 
10. Chi, D. L., Guinn, S., Shands, M. E., Nemawarkar, D., Hill, C. M., Mayhle, M., Do, T. T., Li, S., & Panchal, S. (2024). Socioeconomic vulnerability and access to community water fluoridation in Washington. Journal of the American Dental Association (1939), 155(9), 747–754.e2.
11. Cohen, R., & Bendix, A. (2025, March 28). Utah becomes first state to ban fluoride in public water. NBC News. April 3, 2025.
12. Committee to Coordinate Environmental Health and Related Programs, Ad Hoc Subcommittee on Fluoride (February 1991).  Public Health Service, Department of Health and Human Services. 
13. Environmental Protection Agency. (2021). Questions and Answers on Fluoride. April 3, 2025. 
14. Esmaeilzadeh, F., Movahhed, T., Hasani Yaghooti, M. R., Hoseinzadeh, M., & Babazadeh, S. (2024). Content analysis of fluoride-related posts on Instagram. BMC oral health, 24(1), 1179. 
15. Gelberg KH, Fitzgerald EF, Hwang SA, Dubrow R. Fluoride exposure and childhood osteosarcoma: A case–control study. American Journal of Public Health1995; 85(12):1678–1683.[PubMed Abstract]
16. Green, R., Lanphear, B., Hornung, R., Flora, D., Martinez-Mier, E. A., Neufeld, R., Ayotte, P., Muckle, G., & Till, C. (2019). Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada. JAMA Pediatrics, 173(10), 940–948.
17. Guth, S., Hüser, S., Roth, A., Degen, G., Diel, P., Edlund, K., Eisenbrand, G., Engel, K.-H., Epe, B., Grune, T., Heinz, V., Henle, T., Humpf, H.-U., Jäger, H., Joost, -G., Kulling, S. E., Lampen, A., Mally, A., Marchan, R., & Marko, D. (2020). Toxicity of fluoride: critical evaluation of evidence for human developmental neurotoxicity in epidemiological studies, animal experiments and in vitro analyses. Archives of Toxicology, 94(5), 1375–1415. 
18. Grandjean, P. (2019). Developmental fluoride neurotoxicity: an updated review. Environmental Health, 18(1), 1–17.
19. Hayes C, Douglass CW, Kim FM,  et al. A case–control study of topical and supplemental fluoride use and osteosarcoma risk. Journal of the American Dental Association2021; 152(5):344–353.e10.[PubMed Abstract]
20. International Academy of Biological Dentistry & Medicine. (2025, March 10). Understanding the Benefits and Risks of Fluoride in Toothpaste. Accessed March 12, 2025 
21. Kim FM, Hayes C, Williams PL, et al. An assessment of bone fluoride and osteosarcoma. Journal of Dental Research2011; 90(10):1171–1176. 
22. Kim FM, Hayes C, Burgard SL, et al. A case–control study of fluoridation and osteosarcoma. Journal of Dental Research2020; 99(10):1157–1164. [PubMed Abstract]
23. Kumar, J. V., Moss, M. E., Liu, H., & Fisher-Owens, S. (2023). Association between low fluoride exposure and children’s intelligence: a meta-analysis relevant to community water fluoridation. Public health, 219, 73–84. 
24. Meyer, J., Margaritis, V. & Mendelsohn, A. Consequences of community water fluoridation cessation for Medicaid-eligible children and adolescents in Juneau, Alaska. BMC Oral Health 18, 215 (2018). 
25. National Cancer Institute. (n.d.) Fluoridated Water. February 20, 2025.
26. National Research Council, Subcommittee on Health Effects of Ingested Fluoride. Carcinogenicity of fluoride. In: Health Effects of Ingested Fluoride. Washington, DC: National Academy Press, 1993.National Institute of Dental and Craniofacial Research. (2024, December).
27. The Story of Fluoridation. February 20, 2025. 
28. National Institute of Dental and Craniofacial Research. (2025, February). Community Water Fluoridation. 
29. National Institutes of Health Office of Dietary Supplements. (2024, June 26). Fluoride – Health Professional Fact Sheet. Accessed April 11, 2025.
30. Sexton, C. T., Ha, D. H., Le, T., Lalloo, R., Ford, P., Do, L. G., & Stormon, N. (2024). Socio-economic status and access to fluoridated water in Queensland: an ecological data linkage study. The Medical journal of Australia, 220(2), 74–79. 
31. Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride Exposure and Children’s IQ Scores: A Systematic Review and Meta-Analysis. JAMA Pediatr. Published online January 06, 2025. 
32. Tharnpanich, T., Johns, J., Subongkot, S., Johns, N. P., Kitkhuandee, A., Toomsan, Y., & Luengpailin, S. (2016). Association between high pineal fluoride content and pineal calcification in a low fluoride area. Fluoride, 49(4 Part 2), 472–484. 
33. S. Department of Health and Human Services Federal Panel on Community Water Fluoridation (2015). U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries. Public health reports (Washington, D.C. : 1974), 130(4), 318–331.
34. United States Code. (1996). Subchapter xii—safety of public water systems. March 12, 2025. In Environmental Protection Agency. (2025, March 11) Title XIV of The Public Health Service Act: Safety of Public Water Systems (Safe Drinking Water Act).Accessed March 12, 2025, from
35. Yazdanbakhsh, E., Bohlouli, B., Patterson, S. et al. Community water fluoride cessation and rate of caries-related pediatric dental treatments under general anesthesia in Alberta, Canada. Can J Public Health 115, 305–314 (2024).