Is Fluoride Friend or Foe?

Fortifying public water systems with fluoride (fluoridation) was introduced in the US in the 1940s. Fluoridated water now accounts for public water for two-thirds of the US population.¹

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Public health scientists have described fluoridation as one of the most significant public health initiatives of the past 100 years; however, fluoridation has only been used for 80 years.² Over this period, debate on the benefit vs the risks of fluoride in public water systems has been on a low simmer. Benefit statements for fluoride largely center on oral health and substantial reductions in cavities, whereas risk statements tend to focus on the potential neurocognitive impact.^2-4

An August 2024 report from the National Toxicology Program (NTP) of the US Department of Health and Human Services has substantially increased the debate’s temperature.³ Among the key findings in the NTP report was “moderate confidence” that exposure to fluoride concentrations in water greater than 1.5 mg/L is associated with lower IQ in children. On the other hand, the recommended concentration for fluoride in water systems is 0.7 mg/L, which is less than 50% of the concentration identified in the NTP report and substantially less than the Environmental Protection Agency’s enforceable limit (4 mg/L). Data from the NTP report have been published in a US medical journal and describesimilar observations in other countries.⁴

These toxicology and epidemiological data and the skepticism of some US policy makers about fluoridation are resulting in dynamic changes to fluoridation practices at the state and federal levels. In March 2025, Utah became the first state to ban fluoridation completely.⁵ This law became effective on May 7, 2025. One notable element of this state law is the authorization of pharmacists to prescribe fluoride supplementation for patients, conducted under a statewide collaborative practice agreement that is currently being drafted.⁵

In May 2025, Florida became the second state to ban fluoridation completely. Although the law does not expressly use the word fluoride, it does prohibit mineral supplementation in public water systems, which encompasses a prohibition on fluoride.⁶

At least 8 other states have pending bills or are considering a partial or full ban on fluoride fortification of public water systems. These states include Arkansas, Kentucky, Massachusetts, Nebraska, New Hampshire, North Dakota, South Dakota, and Tennessee. In contrast, Connecticut is considering a bill to protect fluoride in public water systems.⁷

On May 13, 2025, the FDA issued a news release indicating it is taking action to remove concentrated fluoride prescription drug products from the market.⁸ Reasons cited for this policy action include risk of toxicity from accidental poisonings, products the FDA never approved, adverse effects on intestinal microflora, fluoride-enabled behaviors leading to unhealthy sugar consumption, and neurocognitive effects such as lower IQ in children. The agency has set a date of October 31, 2025, to discuss the safety review and public comments.⁸

It seems certain that key organizations and oral health professionals will advocate against these policy shifts. Regardless, this matter will continue to generate debate.

REFERENCES

1. 2022 water fluoridation statistics. CDC. June 6, 2024. Accessed May 15, 2025. https://www.cdc.gov/fluoridation/php/statistics/2022-water-fluoridation-statistics.html

2. Lennon MA. One in a million: the first community trial of water fluoridation. Bull World Health Organ. 2006;84(9)759-760. doi:10.2471/blt.05.028209

3. National Toxicology Program. NTP Monograph on the State of the Science Concerning Fluoride Exposure and Neurodevelopment and Cognition: A Systematic Review. NTP Monograph 08. National Toxicology Program; 2024. Accessed May 15, 2025. https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluoride_final_508.pdf

4. Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride exposure and children’s IQ scores: a systematic review and meta-analysis. JAMA Pediatr. 2025;179(3):282-292. doi:10.1001/jamapediatrics.2024.5542

5. Fluoride Amendments, HR 81 (Utah 2025). Accessed May 15, 2025. https://le.utah.gov/~2025/bills/static/HB0081.html

6. Payne K. Florida is poised to become 2nd state to ban fluoride from public water systems. Associated Press. Updated April 29, 2025. Accessed May 15, 2025. https://apnews.com/article/florida-fluoride-ban-public-water-systems-desantis-74821669626dc478db0aac6c22097f9b

7. Hutchinson D, Castronuovo C. States move to limit fluoride in water after RFK Jr’s scrutiny. Bloomberg Law. February 14, 2025. Accessed May 15, 2025. https://news.bloomberglaw.com/environment-and-energy/states-move-to-limit-fluoride-in-water-after-rfk-jr-s-scrutiny

8. FDA begins action to remove ingestible fluoride prescription drug products for children from the market. News release. FDA. May 13, 2025. Accessed May 15, 2025. https://www.fda.gov/news-events/press-announcements/fda-begins-action-remove-ingestible-fluoride-prescription-drug-products-children-market