Fluoride
Also called sodium fluoride, NaF, fluoride drops, fluoride tablets, monofluorophosphate, fluorine.
Best grade B across 4 graded outcomes Mineral Last checked
The short answer
From 14 sourcesFluoride is a mineral that reduces tooth decay. In children without fluoridated water, drops or tablets cut decay in permanent teeth by about 24% in a Cochrane review but raise the risk of mild dental fluorosis. High-dose fluoride for osteoporosis raised bone density without reducing fractures. The FDA now advises against ingestible fluoride for children under 3.
Every graded outcome on this page
4 rows · line = participantsKey facts
- Tooth decay in children
- Fluoride supplements were linked to 24% less decay in permanent teeth versus no supplement in a Cochrane review of 11 trials (7,196 children); the effect on baby teeth was unclear2
- Fluorosis
- All five studies in a systematic review that looked at it found fluoride supplements raised the risk of mild-to-moderate dental fluorosis4
- Clinical guidance
- The USPSTF (2021, grade B) recommends that primary care clinicians prescribe oral fluoride from 6 months of age for children whose water supply is low in fluoride; the ADA (2010) limits supplements to children at high risk of decay whose main drinking water is low in fluoride1011
- FDA 2025
- In October 2025 the FDA concluded that unapproved ingestible fluoride drug products (prescription drops and tablets) should not be used in children under 3, or in older children who are not at high risk of tooth decay, and warned four companies of enforcement action; it does not cover toothpaste or community water8
- Bones
- Fluoride raised spine bone density by 8.1% at 2 years but did not reduce vertebral fractures, and non-vertebral fractures rose at 4 years (RR 1.85), mainly at high doses5
- Upper limit
- The tolerable upper intake level is 10 mg/day from age 9, and much lower for younger children (1.3 mg at 1-3 years, 2.2 mg at 4-8 years)1
- Newer trials
- A 2021 evidence review for the USPSTF found no new trials of dietary fluoride supplements since its 2014 review14
What it is
Fluoride is the ionic form of fluorine; it hardens tooth enamel and comes from fluoridated water, toothpaste, and drops or tablets.
How it works
EstablishedFluoride inhibits demineralization of tooth enamel, enhances remineralization and reduces the activity of acid-producing bacteria in dental plaque. Taken in, it is incorporated into developing teeth and bone and stimulates new bone formation, although bone made under high fluoride doses may be weaker.16
Compound weight to elemental fluoride
Arithmetic, not advice226mg elemental fluoride500 mg sodium fluoride (drops, chewable tablets, multivitamins) × 45.2%
Forms, side by side
2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Fluoride forms compared
2 forms| 2 forms | Sodium fluoride (drops, chewable tablets, multivitamins) | Sodium monofluorophosphate (toothpaste; older osteoporosis trials) |
|---|---|---|
| Elemental shareOf compound weight | 45.2%1NaF: F 19.00 / NaF 41.99 g/mol = 45.2% fluoride | VariesFluoride content depends on the salt; osteoporosis trials expressed doses as fluoride equivalents |
| Absorption in people | About 80% or more of ingested fluoride is absorbed; adults retain about half, young children up to 80%.1 | Fluoride from toothpaste, in any form, is well absorbed if swallowed.1 |
| GI tolerance | Raises the risk of mild-to-moderate dental fluorosis when given while teeth are forming.4 | High therapeutic doses raised gastrointestinal side effects and non-vertebral fractures.5 |
| Studied for | Tooth decay in children | Osteoporosis (historical) |
- Sodium fluoride (drops, chewable tablets, multivitamins)
- Elemental share
- 45.2%1NaF: F 19.00 / NaF 41.99 g/mol = 45.2% fluoride
- Absorption in people
- About 80% or more of ingested fluoride is absorbed; adults retain about half, young children up to 80%.1
- GI tolerance
- Raises the risk of mild-to-moderate dental fluorosis when given while teeth are forming.4
- Studied for
- Tooth decay in children
- Sodium monofluorophosphate (toothpaste; older osteoporosis trials)
- Elemental share
- VariesFluoride content depends on the salt; osteoporosis trials expressed doses as fluoride equivalents
- Absorption in people
- Fluoride from toothpaste, in any form, is well absorbed if swallowed.1
- GI tolerance
- High therapeutic doses raised gastrointestinal side effects and non-vertebral fractures.5
- Studied for
- Osteoporosis (historical)
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
4 graded outcomes, largest study first4 graded outcomes: 1 improved, 2 no effect, 1 worsened. The largest, a 2011 meta-analysis of 7,196 people on tooth decay in children's permanent teeth, found an improvement. One outcome found a worsening: fractures in postmenopausal osteoporosis (1,429 people).
1Tooth decay in children's permanent teeth
Improved · Grade B · Meta-analysis, 7,196 people, 2011
Children under 16 in randomized or quasi-randomized trials, mostly without fluoridated water
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Tooth decay in children's permanent teeth | Improved | 7,196 | Grade B · Meta-analysis, 2011 | Children under 16 in randomized or quasi-randomized trials, mostly without fluoridated water |
| Fractures in postmenopausal osteoporosis | Worsened | 1,429 | Grade B · Meta-analysis, 2000 | Postmenopausal women in randomized trials of fluoride therapy |
| Tooth decay in children after fluoride in pregnancy | No effect | 938 | Grade C · Systematic review, 2017 | Children of women given fluoride or placebo in late pregnancy (one RCT) |
| Bone density with low-dose fluoride | No effect | 180 | Grade C · RCT, 2013 | Postmenopausal women with osteopenia (New Zealand) |
Every graded row
4 rowsShowing 4 of 4 outcomes. Human trials only.
BGrade BTooth decay in children's permanent teethTooth decay24% less decay (permanent teeth)Meta-analysis · 11 studies
n 7,196 · 2011
Improved Versus no supplement (3 studies), 24% fewer decayed, missing and filled permanent tooth surfaces (95% CI 16-33%). Effect on baby teeth unclear. No difference versus topical fluorides. 10 of 11 trials at unclear risk of bias.
- Design
- Meta-analysis, 11 studies, n = 7,196, 2011
- Population
- Children under 16 in randomized or quasi-randomized trials, mostly without fluoridated water
- Form
- Fluoride tablets, drops, lozenges or chewing gum
- Dose
- 0.25-1 mg/day fluoride (per the NIH ODS summary of this review)
- Duration
- At least 2 years
- Source
- Reference 2 · PubMed 22161414 (opens PubMed)
BGrade BFractures in postmenopausal osteoporosisBone fracturesMore non-vertebral fractures at 4 yearsMeta-analysis · 11 studies
n 1,429 · 2000
Worsened Spine bone density rose 8.1% at 2 years and 16.1% at 4 years, but vertebral fractures did not fall. Non-vertebral fractures rose at 4 years (RR 1.85) and gastrointestinal side effects rose (RR 2.18), especially at high doses.
- Design
- Meta-analysis, 11 studies, n = 1,429, 2000
- Population
- Postmenopausal women in randomized trials of fluoride therapy
- Form
- Sodium fluoride or monofluorophosphate (therapeutic doses)
- Dose
- Therapeutic doses; higher doses and non-slow-release forms carried more risk
- Duration
- 2-4 years
- Source
- Reference 5 · PubMed 11148800 (opens PubMed)
CGrade CTooth decay in children after fluoride in pregnancyPregnancyNo benefit to children's teethSystematic review
n 938 · 2017
No effect No difference in decayed or filled baby-tooth surfaces at age 3 (RR 1.46, 95% CI 0.75-2.85) or 5 (RR 0.84, 95% CI 0.53-1.33); fluorosis at 5 was similar. Very low-quality evidence.
- Design
- Systematic review, n = 938, 2017
- Population
- Children of women given fluoride or placebo in late pregnancy (one RCT)
- Form
- Fluoride tablets during the last 6 months of pregnancy
- Dose
- 1 mg/day (per the NIH ODS summary)
- Duration
- Last 6 months of pregnancy; children followed to age 5
- Source
- Reference 3 · PubMed 29059464 (opens PubMed)
CGrade CBone density with low-dose fluorideBone densityNo change in bone densityRCT
n 180 · 2013
No effect No dose changed bone density at any site versus placebo; a bone-formation marker (P1NP) rose at 5 and 10 mg.
- Design
- RCT, n = 180, 2013
- Population
- Postmenopausal women with osteopenia (New Zealand)
- Form
- Fluoride tablets
- Dose
- 2.5, 5 or 10 mg/day fluoride
- Duration
- 1 year
- Source
- Reference 7 · PubMed 23553866 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Benefit is in permanent teeth, risk is in forming teeth
More bone density did not mean fewer fractures
High-dose fluoride raised spine bone density by double digits yet did not reduce vertebral fractures and increased non-vertebral ones.5
Studied doses, daily needs and limits
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
NIH ODS updated Apr 11, 2025Doses studied in human trials ranged from 0.25-1 mg/day of fluoride in children for 2 to about 4.5 years to 2.5-10 mg/day for a year in postmenopausal women; older osteoporosis trials used higher doses; overall they did not reduce fractures, though a subgroup analysis linked 20 mg/day or less to fewer fractures. These are research doses, not recommendations.1276
Intake reference: Adequate Intake for adults: 4 mg/day for men and 3 mg/day for women (3 mg in pregnancy and breastfeeding). Upper limit from all sources: 10 mg/day from age 9; 0.7-2.2 mg/day for children under 9.1 The UL covers fluoride from all sources and is based on dental and skeletal fluorosis; it is much lower for young children. NIH ODS fact sheet (updated April 11, 2025).
Recommended intake and upper limit by age and sex
mg per day| Age | Male | Female | Pregnancy | Lactation | Upper limit (UL) |
|---|---|---|---|---|---|
| 0–6 months (AI) | 0.01 mg | 0.01 mg | Not set | Not set | 0.7 mg |
| 7–12 months (AI) | 0.5 mg | 0.5 mg | Not set | Not set | 0.9 mg |
| 1–3 years (AI) | 0.7 mg | 0.7 mg | Not set | Not set | 1.3 mg |
| 4–8 years (AI) | 1 mg | 1 mg | Not set | Not set | 2.2 mg |
| 9–13 years (AI) | 2 mg | 2 mg | Not set | Not set | 10 mg |
| 14–18 years (AI) | 3 mg | 3 mg | 3 mg | 3 mg | 10 mg |
| 19+ years (AI) | 4 mg | 3 mg | 3 mg | 3 mg | 10 mg |
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
What Fluoride meets
1 cited rowMedicines 1
Supplements and foods 0
No supplement rows in our sources.
- Reference summary
Choose a medicine or supplement above to read its cited rows here.
Also cited:
Voriconazole (long-term)
NIH fact sheetReference summary
Voriconazole (long-term), for example VFEND: The antifungal contains fluoride; use for about 4 months or more can raise blood fluoride, and its label advises stopping it if skeletal fluorosis or periostitis develops. NIH ODS lists no other clinically relevant medication interactions.
Source 1, NIH Office of Dietary Supplements (2025)
Interactions
1 agent| Agent | What the source says | Evidence |
|---|---|---|
| Medicines1 | ||
| Voriconazole (long-term)e.g. VFEND | The antifungal contains fluoride; use for about 4 months or more can raise blood fluoride, and its label advises stopping it if skeletal fluorosis or periostitis develops. NIH ODS lists no other clinically relevant medication interactions.1 | NIH fact sheet |
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Fluoride and your picks, and between your picks.
- Loading names…
Add a supplement or medicine you take to check it against Fluoride.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
6 groups- Children under 3 and prescription drops
- In October 2025 the FDA concluded that unapproved ingestible fluoride drug products should not be used in children under 3 or in older children not at high risk of tooth decay, and sent enforcement notices to four companies marketing them for those groups. Earlier guidance differs: the USPSTF (2021) recommends oral fluoride from 6 months for children whose water is low in fluoride, and the ADA (2010) limits it to high-risk children with low-fluoride water. A dentist or pediatrician decides whether a child needs drops or tablets.81011
- Children with fluoridated water
- Extra fluoride while teeth are forming raises the risk of dental fluorosis; US dental guidance limits supplements to children whose water has less than 0.6 mg/L fluoride.41
- Pregnancy and breastfeeding
- Fluoride tablets in late pregnancy did not reduce tooth decay in children in the only completed randomized trial. A 2026 pilot trial of 3 mg/day started at 10–20 weeks of pregnancy was stopped early with 30 women completing, too few to show benefit or harm. The Adequate Intake in pregnancy and breastfeeding is 3 mg/day from all sources, the same as for other adult women.3131
- Accidental overdose
- Serious systemic toxicity is estimated at about 5 mg/kg of body weight; concentrated products should be kept away from children.1
- High intakes from water
- A 2024 US National Toxicology Program review linked drinking water above about 1.5 mg/L fluoride to lower IQ in children with moderate confidence, and a 2024 systematic review rated the IQ evidence strong but uncertain. A 2025 meta-analysis of 74 mostly cross-sectional studies found IQ about 1.6 points lower per 1 mg/L more fluoride in urine, but limited data and uncertainty for drinking water below 1.5 mg/L; a 2023 meta-analysis cited by NIH found no link at levels similar to US community water (0.7 mg/L).1912
- Long-term high intake (skeletal fluorosis)
- Chronic excess fluoride intake is linked to skeletal fluorosis, ranging from joint pain and stiffness to osteoporosis, muscle wasting and neurological problems. NIH ODS says it is extremely rare in the US and not caused by recommended tap-water levels; long-term voriconazole use is one recognised route to high fluoride levels.1
Food sources
How much one serving of each food supplies, each amount with its source.
How to read the label
What to check on the Supplement Facts panel.
How to read the label
3 checksFrequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
6 answersDo children need fluoride supplements?
Only some. In children without fluoridated water, supplements cut decay in permanent teeth by about 24%. The USPSTF (2021) supports them from 6 months when water is low in fluoride and the ADA (2010) only for high-risk children, but in 2025 the FDA advised against ingestible fluoride under age 3 and for older children not at high risk. A dentist or pediatrician decides.210118
Is fluoride good for bones?
Does fluoride affect IQ?
How much fluoride is too much?
The upper limit from all sources is 10 mg/day from age 9, and 0.7-2.2 mg/day for younger children. Serious acute toxicity starts around 5 mg per kg of body weight.1
Does fluoride in pregnancy help the baby's teeth?
The only randomized trial found fluoride tablets in late pregnancy did not reduce tooth decay in children.3
Sources
14 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
14 sources- 1Fluoride: Fact Sheet for Health ProfessionalsFact sheet NIH Office of Dietary Supplements, 2025 · ods.od.nih.gov
- 2Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children.Meta-analysis Cochrane Database Syst Rev, 2011 · PMID 22161414
- 3Fluoride supplementation (with tablets, drops, lozenges or chewing gum) in pregnant women for preventing dental caries in the primary teeth of their children.Systematic review Cochrane Database Syst Rev, 2017 · PMID 29059464
- 4Fluoride supplements, dental caries and fluorosis: a systematic review.Systematic review J Am Dent Assoc, 2008 · PMID 18978383
- 5Fluoride for the treatment of postmenopausal osteoporotic fractures: a meta-analysis.Meta-analysis Osteoporos Int, 2000 · PMID 11148800
- 6Effects of treatment with fluoride on bone mineral density and fracture risk--a meta-analysis.Meta-analysis Osteoporos Int, 2008 · PMID 17701094
- 7Low-dose fluoride in postmenopausal women: a randomized controlled trial.RCT J Clin Endocrinol Metab, 2013 · PMID 23553866
- 8FDA Acts to Protect Children from Unapproved Fluoride Drug ProductsSafety communication U.S. Food and Drug Administration, 2025 · fda.gov
- 9Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water.Systematic review Crit Rev Toxicol, 2024 · PMID 38318766
- 10Screening and Interventions to Prevent Dental Caries in Children Younger Than 5 Years: US Preventive Services Task Force Recommendation Statement.Guideline JAMA, 2021 · PMID 34874412
- 11Evidence-based clinical recommendations on the prescription of dietary fluoride supplements for caries prevention: a report of the American Dental Association Council on Scientific Affairs.Guideline J Am Dent Assoc, 2010 · PMID 21158195
- 12Fluoride Exposure and Children's IQ Scores: A Systematic Review and Meta-Analysis.Meta-analysis JAMA Pediatr, 2025 · PMID 39761023
- 13Impact of Short-Term Fluoride Supplementation in Pregnancy on the Maternal Microbiome, Pregnancy, and Neonatal Outcomes: A Pilot Randomized Controlled Trial.Pilot RCT Cureus, 2026 · PMID 42894768
- 14Screening and Interventions to Prevent Dental Caries in Children Younger Than 5 Years: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.Systematic review JAMA, 2021 · PMID 34874413
What changed
Every dated change to this page: what changed, who made it and why.
Change log
2 entries| Date | Change | Who and why |
|---|---|---|
| key facts, who should avoid, FAQ, questions, related | Re-ran the PubMed search for fluoride-supplement trials and reviews (through October 2026): the 2021 USPSTF evidence review found no new supplement trials since 2014, so the Cochrane rows stand. Added the clinical guidance on prescription drops and tablets for children from the primary documents (USPSTF 2021 recommendation statement; ADA 2010 recommendations) beside the FDA 2025 action, a 2025 JAMA Pediatrics meta-analysis on fluoride exposure and IQ, and a 2026 pilot trial of fluoride in pregnancy (stopped early, 30 completers). Added a breastfeeding line from the existing ODS intake table (LactMed has no entry for dietary fluoride, only fluorine-18 imaging), page questions and a goal-hub link. ODS figures unchanged; interactions unchanged (ODS lists only voriconazole). | Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md |
| all | Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record, none retracted) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice. | Writer: Kymata Health EditorialTrigger: new page |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.