Xylitol

Also called birch sugar, wood sugar, E967, xylit.

Best grade B across 23 graded outcomes Other Last checked Oct 21, 2026

The short answer

From 33 sources

Xylitol is a sugar alcohol that sweetens sugar-free gum, mints and toothpaste. In Finnish daycare trials, xylitol gum or syrup five times a day cut ear infections by about a quarter (grade B), but fewer daily doses did not work. Evidence for fewer cavities is mostly low quality, and large amounts cause loose stools. It is dangerous to dogs.

Every graded outcome on this page

23 rows · line = participants

Grade BAcute ear infections in healthy children at daycare (pooled)Ear infectionsn 1,826
Grade BAcute ear infections in daycare children: syrup, gum or lozengeEar infectionsn 857
Grade BAcute ear infections in daycare children (chewing gum)Ear infectionsn 306
Grade CPreterm and low-birthweight births (gum before and during pregnancy)Pregnancyn 10,069
Grade CTooth decay in permanent teeth of children and teens (pooled)Tooth decayn 6,325
Grade CTooth decay in children and adults (pooled)Tooth decayn 5,903
Grade CNew cavities in schoolchildren (candies and gum)Tooth decayn 740
Grade CTooth decay in schoolchildren: xylitol vs sorbitol candyTooth decayn 485
Grade CChronic sinusitis symptoms with xylitol versus saline rinses (pooled)Sinus symptomsn 263
Grade CGas and diarrhoea in toddlers on daily xylitol solutionGut tolerancen 120
Grade CNose and sinus symptoms after nasal surgery (rinse)Sinus symptomsn 100
Grade CGut symptoms after one large dose in a drinkGut tolerancen 64
Grade DHeart attack and stroke risk with higher blood xylitolHeart and plateletsn 2,149
Grade DEar infections in young children (xylitol syrup twice a day)Ear infectionsn 250
Grade DEarly childhood cavities with xylitol fluoride toothpasteTooth decayn 168
Grade DCavities between teeth in high-risk adolescents (lozenges)Tooth decayn 160
Grade DPassing cavity-causing bacteria from mother to childTooth decayn 107
Grade DGlucose, insulin and gut hormones after a large doseBlood sugarn 20
Grade DChronic sinus symptoms (rinse)Sinus symptomsn 15
Grade DBlood glucose and insulin rise compared with glucoseBlood sugarn 8
No effectNew cavities in adults at high caries riskTooth decayn 691
No effectAcute ear infections with xylitol three times a dayEar infectionsn 663
No effectEar infections in otitis-prone young children (xylitol solution)Ear infectionsn 326
20 more graded outcomes, in the evidence chapter

Key facts

What it is: A five-carbon sugar alcohol (C₅H₁₂O₅) found in many plants and used as a sugar substitute; the FDA lists it among the sweeteners that may carry the claim that they do not promote tooth decay^3,2
Where it comes from: Present in small amounts in fruits and vegetables such as plums, strawberries, cauliflower and pumpkin, and made by the body; commercial xylitol is made from xylose in agricultural or forestry material, and labels may call it birch sugar or wood sugar^32,24,4
Strongest human evidence: Ear infections in healthy daycare children (B): in three Finnish trials of 1,826 children, xylitol lowered the risk of acute otitis media from about 30% to 22% (RR 0.75)¹⁴
Schedule mattered: The positive ear trials gave about 8 to 10 g a day split over five doses; 9.6 g in three doses (663 children) and 5 g three times a day (326 children) did no better than control^16,17,18
Tooth decay: Cochrane (10 trials, 5,903 people) found low-quality evidence that a fluoride toothpaste with 10% xylitol cut cavities by 13% versus fluoride alone; evidence for other products was insufficient⁵
Adults: In the 691-person X-ACT trial, 5 g of xylitol lozenges a day for 33 months did not significantly reduce new cavities in adults at high risk⁶
Blood sugar: Glycaemic index 7 (glucose = 100) after 25 g in healthy men; a 50 g load had only minimal effects on glucose and insulin^21,22
Gut tolerance: Single doses of 35 g and 50 g in water caused watery stools and other gut symptoms in young adults; Cochrane lists mouth sores, cramps, bloating, constipation, flatulence and loose stools among side effects reported in trials^20,5
Platelet signal: A 2024 study linked higher fasting blood xylitol (not diet, which was not measured) to more heart attacks, strokes and deaths over 3 years, and a 30 g xylitol drink raised platelet reactivity in 10 volunteers; this is an association plus a small uncontrolled experiment, not proof of harm^23,24
Dogs: FDA warns that xylitol can cause a rapid, life-threatening drop in blood sugar in dogs within 10 to 60 minutes, and liver failure has been reported^4,28

What it is

Xylitol is a five-carbon sugar alcohol found in plants and used as a sugar substitute in gum, mints, toothpaste and tabletop sweeteners.

How it works

Proposed

Xylitol is a five-carbon polyol whose absorption from the gut is limited; the part that is not absorbed reaches the colon, where gut bacteria ferment it, which is linked to its laxative effect at high intakes. Habitual use lowers counts of mutans streptococci, the main cavity-causing mouth bacteria, in saliva and plaque. In the lab it reduces how well pneumococci and Haemophilus influenzae stick to nasal-lining cells, the proposed reason for fewer ear infections. In people it causes only a small rise in blood glucose and insulin.^{31,1,30,14,21}

Forms side by side: gum, candies, syrup, toothpaste and rinses

6 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Xylitol forms compared

6 forms

Xylitol forms compared: 6 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
6 forms	Chewing gum	Candies, mints and lozenges	Syrup or oral solution	Toothpaste with xylitol and fluoride	Granulated xylitol (tabletop sweetener, birch sugar)	Nasal rinse (xylitol dissolved in water)
Absorption in people	No head-to-head human data. Gum was the form in both positive Finnish ear trials, chewed five times a day.^15,16,17	No head-to-head human data. Lozenges lowered ear infections less than syrup or gum in the 857-child trial (20%, not significant).¹⁶	No head-to-head human data. Syrup at 10 g/day in five doses cut ear infections; 5 g three times a day did not.^16,18,17	No head-to-head human data.⁵	Raises blood glucose only slightly (glycaemic index 7 after 25 g).²¹	Used inside the nose; not studied for absorption.²⁵
GI tolerance	Two of 157 children on 8.4 g/day of xylitol gum had diarrhoea; no other side effects were noted.¹⁵	Five 1 g lozenges a day were used for 33 months in adults; trials list mouth sores, cramps, bloating, flatulence and loose stools among reported side effects of xylitol products.^6,5	In toddlers, 5 g three times a day or 7.5 g once a day for 3 months caused no more gas or diarrhoea than placebo.¹⁹	Cochrane found no adverse effects associated with xylitol toothpaste.⁵	35 g or more at once in a drink caused watery stools in young adults; the dose per sitting matters.²⁰	Three people (21%) disliked the sweet taste and one had transient stinging; no one stopped because of intolerance.²⁵
Studied for	Ear infections in daycare children (grade B); tooth decay in schoolchildren (C); mother-to-child spread of mouth bacteria (D)	Tooth decay in children (C) and adults (no effect)	Ear infections in young children (B with five doses a day; no effect with three)	Tooth decay in children (C): 13% fewer cavities than fluoride alone in one population	Blood sugar response (D); gut tolerance studies	Sinus symptoms after nasal surgery (C) and in chronic rhinosinusitis (D)

Chewing gum
Absorption in people
No head-to-head human data. Gum was the form in both positive Finnish ear trials, chewed five times a day.^15,16,17
GI tolerance
Two of 157 children on 8.4 g/day of xylitol gum had diarrhoea; no other side effects were noted.¹⁵
Studied for
Ear infections in daycare children (grade B); tooth decay in schoolchildren (C); mother-to-child spread of mouth bacteria (D)
Candies, mints and lozenges
Absorption in people
No head-to-head human data. Lozenges lowered ear infections less than syrup or gum in the 857-child trial (20%, not significant).¹⁶
GI tolerance
Five 1 g lozenges a day were used for 33 months in adults; trials list mouth sores, cramps, bloating, flatulence and loose stools among reported side effects of xylitol products.^6,5
Studied for
Tooth decay in children (C) and adults (no effect)
Syrup or oral solution
Absorption in people
No head-to-head human data. Syrup at 10 g/day in five doses cut ear infections; 5 g three times a day did not.^16,18,17
GI tolerance
In toddlers, 5 g three times a day or 7.5 g once a day for 3 months caused no more gas or diarrhoea than placebo.¹⁹
Studied for
Ear infections in young children (B with five doses a day; no effect with three)
Toothpaste with xylitol and fluoride
Absorption in people
No head-to-head human data.⁵
GI tolerance
Cochrane found no adverse effects associated with xylitol toothpaste.⁵
Studied for
Tooth decay in children (C): 13% fewer cavities than fluoride alone in one population
Granulated xylitol (tabletop sweetener, birch sugar)
Absorption in people
Raises blood glucose only slightly (glycaemic index 7 after 25 g).²¹
GI tolerance
35 g or more at once in a drink caused watery stools in young adults; the dose per sitting matters.²⁰
Studied for
Blood sugar response (D); gut tolerance studies
Nasal rinse (xylitol dissolved in water)
Absorption in people
Used inside the nose; not studied for absorption.²⁵
GI tolerance
Three people (21%) disliked the sweet taste and one had transient stinging; no one stopped because of intolerance.²⁵
Studied for
Sinus symptoms after nasal surgery (C) and in chronic rhinosinusitis (D)

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

23 graded outcomes, largest study first

23 graded outcomes: 13 improved, 8 no effect, 2 worsened. The largest, a 2025 randomized trial of 10,069 people on preterm and low-birthweight births (gum before and during pregnancy), found an improvement. 2 outcomes found a worsening: heart attack and stroke risk with higher blood xylitol (2,149 people) and gut symptoms after one large dose in a drink (64).

By sizeTable

1Preterm and low-birthweight births (gum before and during pregnancy)

Improved · Grade C · RCT, 10,069 people, 2025

Women at eight health centres in and around Lilongwe, Malawi (cluster-randomized, open-label)

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Preterm and low-birthweight births (gum before and during pregnancy)	Improved	10,069	Grade C · RCT, 2025	Women at eight health centres in and around Lilongwe, Malawi (cluster-randomized, open-label)
Tooth decay in permanent teeth of children and teens (pooled)	Improved	6,325	Grade C · Meta-analysis, 2024	Children and adolescents aged 6 to 18 in 11 randomized and 4 controlled trials
Tooth decay in children and adults (pooled)	Improved	5,903	Grade C · Meta-analysis, 2015	Children and adults in 10 randomized trials (7 at high risk of bias)
Heart attack and stroke risk with higher blood xylitol	Worsened	2,149	Grade D · Observational, 2024	Adults with a high burden of heart risk factors having elective diagnostic heart evaluations (validation cohort; discovery cohort of 1,157), plus 10 healthy volunteers in a drink study
Acute ear infections in healthy children at daycare (pooled)	Improved	1,826	Grade B · Meta-analysis, 2016	Healthy Finnish children attending daycare in three randomized trials (five trials, 3,405 children, reviewed)
Acute ear infections in daycare children: syrup, gum or lozenge	Improved	857	Grade B · RCT, 1998	Healthy children recruited from day care centres, five randomized groups
New cavities in schoolchildren (candies and gum)	Improved	740	Grade C · RCT, 2000	10-year-old children in 12 Estonian schools, in three clusters
New cavities in adults at high caries risk	No effect	691	No-effect grade · RCT, 2013	Adults aged 21 to 80 at elevated caries risk at three sites (X-ACT)
Acute ear infections with xylitol three times a day	No effect	663	No-effect grade · RCT, 2007	Healthy day care children during the respiratory infection season
Tooth decay in schoolchildren: xylitol vs sorbitol candy	No effect	485	Grade C · RCT, 2014	First- and second-grade children in southeastern Estonia
Ear infections in otitis-prone young children (xylitol solution)	No effect	326	No-effect grade · RCT, 2014	Otitis-prone children aged 6 months to 5 years in US primary care practices
Acute ear infections in daycare children (chewing gum)	Improved	306	Grade B · RCT, 1996	Children aged about 5 in eleven Oulu day care nurseries, most with past recurrent ear infections
Chronic sinusitis symptoms with xylitol versus saline rinses (pooled)	Improved	263	Grade C · Meta-analysis, 2026	People with chronic rhinosinusitis, including after endoscopic sinus surgery (7 studies)
Ear infections in young children (xylitol syrup twice a day)	No effect	250	Grade D · RCT, 2024	Children aged 1 to 5 years in 11 Canadian primary care practices (250 randomised)
Early childhood cavities with xylitol fluoride toothpaste	No effect	168	Grade D · RCT, 2014	Four- to five-year-olds in four Head Start classrooms in the Marshall Islands (cluster-randomized)
Cavities between teeth in high-risk adolescents (lozenges)	No effect	160	Grade D · RCT, 2008	Children aged 10 to 12 at high caries risk, with a non-randomized no-tablet reference group of 70
Gas and diarrhoea in toddlers on daily xylitol solution	No effect	120	Grade C · RCT, 2007	Children 6 to 36 months old in a practice-based research network (SCOR)
Passing cavity-causing bacteria from mother to child	Improved	107	Grade D · RCT, 2010	Pregnant women with high salivary mutans streptococci in Japan, and their children to age 24 months
Nose and sinus symptoms after nasal surgery (rinse)	Improved	100	Grade C · Crossover RCT, 2019	Patients after endoscopic sinus surgery, septoplasty or both at a tertiary referral centre
Gut symptoms after one large dose in a drink	Worsened	64	Grade C · RCT, 2007	Healthy students aged 18 to 24 at the University of Salford (UK)
Glucose, insulin and gut hormones after a large dose	Improved	20	Grade D · Crossover RCT, 2022	Healthy volunteers
Chronic sinus symptoms (rinse)	Improved	15	Grade D · Crossover RCT, 2011	Adults with chronic rhinosinusitis (20 enrolled, 15 analysed)
Blood glucose and insulin rise compared with glucose	Improved	8	Grade D · Crossover RCT, 1997	Healthy, non-obese men

Every graded row

23 rows

Form tested

Showing 23 of 23 outcomes. Human trials only.

Grade BAcute ear infections in healthy children at daycare (pooled)Ear infectionsRR 0.75 (30% to 22%)Meta-analysis · 3 studies
n 1,826 · 2016

Improved Acute otitis media fell from about 30% to 22% (RR 0.75, 95% CI 0.65 to 0.88; moderate-quality evidence). Xylitol did not help when given only during a respiratory infection (RR 1.13) or in otitis-prone children (RR 0.90). Abdominal discomfort and rash were no more common than with control.

Design: Meta-analysis, 3 studies, n = 1,826, 2016
Population: Healthy Finnish children attending daycare in three randomized trials (five trials, 3,405 children, reviewed)
Form: Xylitol chewing gum, lozenges or syrup
Dose: About 8 to 10 g/day in the pooled trials
Duration: 2 to 3 months
Source: Reference 14 · PubMed 27486835 (opens PubMed)

Grade BAcute ear infections in daycare children: syrup, gum or lozengeEar infections41% vs 29% with syrupRCT
n 857 · 1998

Improved At least one ear infection occurred in 41% on control syrup vs 29% on xylitol syrup (a 30% decrease). Xylitol gum lowered the rate by 40% versus control gum; the 20% fall with lozenges was not significant. Children on xylitol syrup or gum needed antibiotics less often.

Design: RCT, n = 857, 1998
Population: Healthy children recruited from day care centres, five randomized groups
Form: Xylitol syrup, chewing gum or lozenge vs control syrup or control gum
Dose: 8.4 g/day (gum) to 10 g/day (syrup)
Duration: 3 months
Source: Reference 16 · PubMed 9755259 (opens PubMed)

Grade BAcute ear infections in daycare children (chewing gum)Ear infections20.8% vs 12.1%RCT
n 306 · 1996

Improved At least one ear infection occurred in 20.8% on sucrose gum vs 12.1% on xylitol gum (difference 8.7%, 95% CI 0.4% to 17.0%). Fewer children on xylitol received antibiotics (18.5% vs 28.9%). Two children on xylitol had diarrhoea.

Design: RCT, n = 306, 1996
Population: Children aged about 5 in eleven Oulu day care nurseries, most with past recurrent ear infections
Form: Xylitol chewing gum vs sucrose gum
Dose: 8.4 g/day xylitol
Duration: 2 months
Source: Reference 15 · PubMed 8916749 (opens PubMed)

Grade CPreterm and low-birthweight births (gum before and during pregnancy)PregnancyRR 0.76 for preterm birthRCT
n 10,069 · 2025

Improved Preterm birth was 12.6% with xylitol gum vs 16.5% with education alone (RR 0.76, 95% CI 0.57 to 0.99) and babies under 2,500 g 8.9% vs 12.9% (RR 0.70). Neonatal deaths were also fewer (0.2% vs 0.4%).

Design: RCT, n = 10,069, 2025
Population: Women at eight health centres in and around Lilongwe, Malawi (cluster-randomized, open-label)
Form: Xylitol chewing gum plus oral health education vs education alone
Dose: Gum twice a day
Duration: Periconception through pregnancy
Source: Reference 27 · PubMed 39541971 (opens PubMed)

Grade CTooth decay in permanent teeth of children and teens (pooled)Tooth decaySMD −0.50Meta-analysis · 15 studies
n 6,325 · 2024

Improved Xylitol reduced caries compared with no treatment or placebo (SMD −0.50, 95% CI −0.85 to −0.16); sorbitol had a smaller effect (SMD −0.10). Twelve of 15 studies were at moderate or high risk of bias.

Design: Meta-analysis, 15 studies, n = 6,325, 2024
Population: Children and adolescents aged 6 to 18 in 11 randomized and 4 controlled trials
Form: Xylitol (11 studies), sorbitol and erythritol products
Dose: As given in each included study
Duration: Varied by study
Source: Reference 7 · PubMed 38762077 (opens PubMed)

Grade CTooth decay in children and adults (pooled)Tooth decay−13% with xylitol toothpasteMeta-analysis · 10 studies
n 5,903 · 2015

Improved Fluoride toothpaste with 10% xylitol may reduce cavities by 13% versus fluoride-only toothpaste (4,216 children, low-quality evidence). Evidence for lozenges, tablets, wipes and syrup was too uncertain to show a benefit; one infant study found 8 g/day syrup reduced caries by 58% versus 2.67 g/day.

Design: Meta-analysis, 10 studies, n = 5,903, 2015
Population: Children and adults in 10 randomized trials (7 at high risk of bias)
Form: Xylitol toothpaste, syrup, lozenges, sucking tablets or wipes
Dose: Varied; 10% xylitol fluoride toothpaste in the main finding
Duration: Up to 2.5 to 3 years
Source: Reference 5 · PubMed 25809586 (opens PubMed)

Grade CNew cavities in schoolchildren (candies and gum)Tooth decay35% to 60% fewer cavitiesRCT
n 740 · 2000

Improved After 3 years, all xylitol groups had 35% to 60% fewer new cavities than their control groups, with no consistent difference between candies and gum.

Design: RCT, n = 740, 2000
Population: 10-year-old children in 12 Estonian schools, in three clusters
Form: Xylitol candies or chewing gum under teacher supervision
Dose: 5 g/day on school days
Duration: 2 or 3 years
Source: Reference 9 · PubMed 10830649 (opens PubMed)

Grade CTooth decay in schoolchildren: xylitol vs sorbitol candyTooth decayNo better than sorbitolRCT
n 485 · 2014

No effect Children on xylitol candy did not have fewer dentin cavities than the sorbitol control group; the erythritol group had fewer dentin cavities and a longer time before lesions developed than both.

Design: RCT, n = 485, 2014
Population: First- and second-grade children in southeastern Estonia
Form: Xylitol, erythritol or sorbitol (control) candies
Dose: About 7.5 g/day of polyol on school days
Duration: 3 years
Source: Reference 10 · PubMed 24852946 (opens PubMed)

Grade CChronic sinusitis symptoms with xylitol versus saline rinses (pooled)Sinus symptomsSMD 0.63 (symptoms only)Meta-analysis · 7 studies
n 263 · 2026

Improved Xylitol rinses improved overall sinonasal well-being more than saline (SMD 0.63, 95% CI 0.01 to 1.24), with better NOSE and SNOT symptom scores; endoscopic scores, sense of smell and mucus clearance did not change. Side effects were minimal and transient.

Design: Meta-analysis, 7 studies, n = 263, 2026
Population: People with chronic rhinosinusitis, including after endoscopic sinus surgery (7 studies)
Form: Xylitol nasal irrigation vs saline irrigation
Dose: Nasal irrigation (as given in each study)
Duration: Varied by study
Source: Reference 34 · PubMed 41186273 (opens PubMed)

Grade CGas and diarrhoea in toddlers on daily xylitol solutionGut toleranceNo more gas or diarrhoea than placeboRCT
n 120 · 2007

No effect Excessive gas or diarrhoea affected 10% to 27% of children on xylitol in a given month, which did not differ from placebo; withdrawals and visits for stomach complaints did not differ either. By month 3, about 90% accepted the solution easily or with minor difficulty.

Design: RCT, n = 120, 2007
Population: Children 6 to 36 months old in a practice-based research network (SCOR)
Form: Oral xylitol solution vs placebo
Dose: 5 g three times a day or 7.5 g once a day
Duration: 3 months
Source: Reference 19 · PubMed 17097152 (opens PubMed)

Grade CNose and sinus symptoms after nasal surgery (rinse)Sinus symptomsBetter SNOT-20 after sinus surgeryCrossover RCT
n 100 · 2019

Improved After sinus surgery, the SNOT-20 nasal symptom score improved more with xylitol than saline (P = 0.022), as did sneezing, headache and facial pain; after septoplasty, stuffiness improved more. More than half of patients preferred the xylitol rinse.

Design: Crossover RCT, n = 100, 2019
Population: Patients after endoscopic sinus surgery, septoplasty or both at a tertiary referral centre
Form: Xylitol nasal irrigation vs saline irrigation
Dose: Nasal irrigation (amount not stated in the abstract)
Duration: Postoperative crossover periods (length not stated in the abstract)
Source: Reference 26 · PubMed 30274540 (opens PubMed)

Grade CGut symptoms after one large dose in a drinkGut toleranceWatery stools from 35 gRCT
n 64 · 2007

Worsened 50 g of xylitol increased nausea, bloating, rumbling, colic, watery stools and bowel movements compared with sucrose; 35 g also increased watery stools. At every dose xylitol caused more watery stools than erythritol.

Design: RCT, n = 64, 2007
Population: Healthy students aged 18 to 24 at the University of Salford (UK)
Form: Xylitol or erythritol in water vs 45 g sucrose
Dose: Single doses of 20, 35 and 50 g
Duration: One test day per dose, 7-day washouts
Source: Reference 20 · PubMed 16988647 (opens PubMed)

Grade DHeart attack and stroke risk with higher blood xylitolHeart and plateletsHR 1.57 (top vs bottom third)Observational
n 2,149 · 2024

Worsened People in the top third of fasting blood xylitol had more major cardiovascular events (death, heart attack or stroke) over 3 years than those in the bottom third (adjusted hazard ratio 1.57, 95% CI 1.12 to 2.21). In the volunteers, a 30 g xylitol drink raised blood levels about 1,000-fold for a few hours and increased platelet responsiveness in every subject compared with their own pre-drink tests.

Design: Observational, n = 2,149, 2024
Population: Adults with a high burden of heart risk factors having elective diagnostic heart evaluations (validation cohort; discovery cohort of 1,157), plus 10 healthy volunteers in a drink study
Form: Fasting plasma xylitol (cohort); a xylitol-sweetened drink (volunteers)
Dose: Not applicable in the cohorts (one fasting blood level, no diet data); 30 g of xylitol in water in the volunteer study
Duration: 3-year follow-up
Source: Reference 23 · PubMed 38842092 (opens PubMed)

Grade DEar infections in young children (xylitol syrup twice a day)Ear infectionsOR 2.04 (n.s.)RCT
n 250 · 2024

No effect Clinician-diagnosed ear infections: 6 with xylitol versus 3 with placebo (OR 2.04, 95% CI 0.43 to 12.92); no difference in colds or caregiver-reported cavities. Diarrhoea was the most common adverse event (34% xylitol, 28% placebo).

Design: RCT, n = 250, 2024
Population: Children aged 1 to 5 years in 11 Canadian primary care practices (250 randomised)
Form: Xylitol syrup vs sorbitol placebo syrup
Dose: Syrup twice a day (amount not stated in the abstract)
Duration: 6 months
Source: Reference 33 · PubMed 37890960 (opens PubMed)

Grade DEarly childhood cavities with xylitol fluoride toothpasteTooth decay2.5 vs 1.4 surfaces (n.s.)RCT
n 168 · 2014

No effect The mean increase in decayed surfaces was 2.5 with xylitol toothpaste and 1.4 with the sorbitol toothpaste; the difference was not significant (P = 0.07). No adverse effects were reported.

Design: RCT, n = 168, 2014
Population: Four- to five-year-olds in four Head Start classrooms in the Marshall Islands (cluster-randomized)
Form: Toothpaste with 31% xylitol and fluoride vs fluoride-sorbitol toothpaste
Dose: Supervised toothbrushing
Duration: 6 months
Source: Reference 12 · PubMed 24709430 (opens PubMed)

Grade DCavities between teeth in high-risk adolescents (lozenges)Tooth decayNo differenceRCT
n 160 · 2008

No effect No significant difference in new cavities between groups or versus the no-tablet group. Only 41% followed the schedule well and 28% dropped out.

Design: RCT, n = 160, 2008
Population: Children aged 10 to 12 at high caries risk, with a non-randomized no-tablet reference group of 70
Form: Xylitol or xylitol-fluoride lozenges
Dose: 2.5 g/day xylitol in six lozenges
Duration: 2 years
Source: Reference 11 · PubMed 18341562 (opens PubMed)

Grade DPassing cavity-causing bacteria from mother to childTooth decayColonization 8.8 months laterRCT
n 107 · 2010

Improved Children of mothers who chewed xylitol gum were less likely to be colonized by mutans streptococci between 9 and 24 months and acquired them 8.8 months later than children in the control group.

Design: RCT, n = 107, 2010
Population: Pregnant women with high salivary mutans streptococci in Japan, and their children to age 24 months
Form: Xylitol chewing gum chewed by the mother vs no gum
Dose: Maternal gum from the sixth month of pregnancy
Duration: 13 months of chewing; children followed to 24 months
Source: Reference 13 · PubMed 19948944 (opens PubMed)

Grade DGlucose, insulin and gut hormones after a large doseBlood sugarMinimal glucose and insulin riseCrossover RCT
n 20 · 2022

Improved Xylitol had only minimal effects on glucose and insulin and raised the gut hormones CCK and PYY. It also increased blood flow in the hypothalamus on brain imaging, which glucose did not.

Design: Crossover RCT, n = 20, 2022
Population: Healthy volunteers
Form: 50 g xylitol, 75 g erythritol, 75 g glucose or water given into the stomach
Dose: 50 g single dose
Duration: Single test sessions
Source: Reference 22 · PubMed 34404339 (opens PubMed)

Grade DChronic sinus symptoms (rinse)Sinus symptoms−2.43 vs +3.93 SNOT-20Crossover RCT
n 15 · 2011

Improved SNOT-20 scores fell by 2.43 points during xylitol rinses and rose by 3.93 during saline (P = 0.0437); visual analogue scores did not differ. Three people (21%) disliked the sweet taste and one had brief stinging.

Design: Crossover RCT, n = 15, 2011
Population: Adults with chronic rhinosinusitis (20 enrolled, 15 analysed)
Form: Xylitol mixed with water vs saline as a nasal rinse
Dose: Daily irrigation
Duration: Two 10-day periods
Source: Reference 25 · PubMed 21994147 (opens PubMed)

Grade DBlood glucose and insulin rise compared with glucoseBlood sugarGlycaemic index 7Crossover RCT
n 8 · 1997

Improved Glucose, insulin and C-peptide rose less after xylitol than after glucose. With glucose set at 100, the glycaemic index of xylitol was 7. No reactive low blood sugar followed xylitol, unlike glucose.

Design: Crossover RCT, n = 8, 1997
Population: Healthy, non-obese men
Form: Xylitol, lactitol or glucose drink
Dose: 25 g single dose
Duration: Single test sessions
Source: Reference 21 · PubMed 9094877 (opens PubMed)

No effectNew cavities in adults at high caries riskTooth decay−10% (n.s.)RCT
n 691 · 2013

No effect Xylitol reduced the caries increment by 10%, less than one-third of a tooth surface a year, which was not statistically significant. There was no dose-response effect.

Design: RCT, n = 691, 2013
Population: Adults aged 21 to 80 at elevated caries risk at three sites (X-ACT)
Form: Xylitol lozenges vs placebo lozenges
Dose: Five 1.0 g lozenges a day (5 g/day)
Duration: 33 months
Source: Reference 6 · PubMed 23283923 (opens PubMed)

No effectAcute ear infections with xylitol three times a dayEar infections30% vs 28% (n.s.)RCT
n 663 · 2007

No effect At least one ear infection was diagnosed in 30% on control and 28% on xylitol; 142 vs 156 episodes in total. The differences were not significant.

Design: RCT, n = 663, 2007
Population: Healthy day care children during the respiratory infection season
Form: Xylitol chewing gum or mixture vs control product
Dose: 9.6 g/day in three doses (control 0.5 g/day)
Duration: 3 months
Source: Reference 17 · PubMed 17468653 (opens PubMed)

No effectEar infections in otitis-prone young children (xylitol solution)Ear infectionsHR 0.88 (n.s.)RCT
n 326 · 2014

No effect Time to the first diagnosed ear infection did not differ (hazard ratio 0.88, 95% CI 0.61 to 1.3); episodes were 0.53 vs 0.59 per 90 days and antibiotic days 6.8 vs 6.4. Children who took nearly all their doses did no better.

Design: RCT, n = 326, 2014
Population: Otitis-prone children aged 6 months to 5 years in US primary care practices
Form: Viscous xylitol solution vs placebo
Dose: 5 g three times a day (15 g/day)
Duration: 3 months
Source: Reference 18 · PubMed 24394686 (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.

Doses per day mattered more than grams per day

About 8.4 to 10 g a day in five doses cut ear infections, while 9.6 g a day in three doses did nothing. The total was similar; the number of doses was not.^15,16,17,18

What 25% fewer ear infections means in absolute terms

Cochrane's risk fell from about 30% to 22%, so roughly 8 fewer children in every 100 had an ear infection over the study period.¹⁴

Five 1 g lozenges is the adult trial dose

X-ACT adults took 5 g a day for 33 months and got a 10% reduction that was not significant, less than one-third of a tooth surface a year.⁶

Studied doses

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

Doses studied in human trials ranged from 2.5 g a day in lozenges to 15 g a day of solution in toddlers. The positive ear-infection trials used about 8.4 to 10 g a day split into five doses for 2 to 3 months; cavity trials used about 5 to 7.5 g a day for 2 to 3 years; the adult X-ACT trial used 5 g a day for 33 months. Single test doses of 20 to 50 g were used to study blood sugar and gut tolerance. These are research amounts, not product directions.^{11,18,15,16,9,10,6,20,21}

When trials measured an effect

3 outcomes

How long trials ran before effects were measured
Outcome	Measured at	Basis
Ear infections in daycare children	Measured over 2 to 3 months of daily use	Finnish randomized trials (306 and 857 children)^15,16
Fewer new cavities	Measured after 2 to 3 years	School trials and the Cochrane review^9,5
Loose stools from a large dose	The same day (single 35 to 50 g dose)	Tolerance trial in 64 young adults²⁰

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.

Interactions

0 agents

None found in our sources.

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Xylitol and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Xylitol.

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

5 groups

Homes with dogs: FDA warns that xylitol can trigger a rapid drop in blood sugar in dogs within 10 to 60 minutes, and that signs may be delayed 12 to 24 hours; liver failure has also been reported. It appears less dangerous to cats, but ferrets have had seizures. Keep gum, mints, toothpaste, some nut butters and chewable vitamins with xylitol out of reach.^4,28
Sensitive digestion: Large single amounts in a drink (35 g or more) caused watery stools and gut symptoms in young adults. Cochrane lists bloating, flatulence, cramps and loose stools among side effects reported in trials.^20,5
Young children: Trials in toddlers used up to 15 g a day of xylitol solution without more gas or diarrhoea than placebo; the gum trials enrolled children around age 5.^19,15
People at high risk of blood clots: A 2024 study linked higher fasting blood xylitol to more heart attacks and strokes and found a 30 g xylitol drink raised platelet reactivity. It did not measure diet and does not prove harm, but people with heart disease or clotting risk may wish to discuss large daily amounts with their clinician.^23,24
Pregnancy: A large cluster-randomized trial in Malawi gave xylitol gum twice daily from before conception through pregnancy and found fewer preterm births and newborn deaths; it was open-label, and other pregnancy data are limited.²⁷

Xylitol and dogs

5 notes

Safe amounts for people can poison a dog. This is the most important safety point on this page.

Why dogs and not people: In people xylitol does not stimulate insulin release; in dogs it is absorbed quickly and can cause a strong insulin release and a profound fall in blood sugar.⁴
Signs: Vomiting, then weakness, staggering, collapse and seizures. FDA says signs can take 12 to 24 hours to appear, so a dog may need hospital monitoring.⁴
The liver: Veterinary reports describe acute liver failure and bleeding problems after xylitol ingestion in dogs.^28,29
Where it hides: FDA lists breath mints, baked goods, cough syrup, chewable vitamins, mouthwash, toothpaste, some peanut and nut butters, over-the-counter medicines, dietary supplements and sugar-free desserts. Labels may say birch sugar or wood sugar.⁴
What to do: FDA's advice is to call a vet, emergency clinic or animal poison control centre right away if a dog may have eaten xylitol, and to use pet toothpaste, never human toothpaste, for pets.⁴

The 2024 platelet findings in context

4 notes

What was found, and what it does not show.

What was found: In 2,149 adults having heart evaluations, the top third of fasting blood xylitol had a 1.57 times higher adjusted risk of heart attack, stroke or death over 3 years than the bottom third. Xylitol made platelets more reactive in lab tests.²³
The volunteer experiment: In 10 healthy volunteers, 30 g of xylitol in water raised blood xylitol about 1,000-fold within 30 minutes, back to near baseline within 6 hours, and increased platelet responsiveness in every subject compared with their own pre-drink tests. There was no control drink, and no clinical events were measured.²³
What the design cannot show: The heart cohorts measured one fasting blood level and collected no diet data. Because eaten xylitol clears within hours, the authors conclude those fasting levels mostly reflect the body's own production, not recent eating. The cohorts were people with many heart risk factors, so the results may not apply to everyone, and an association cannot prove that eating xylitol causes events.²³
The other side: A 2025 review notes that xylitol is also made by the body, that Mendelian randomisation studies and large intravenous doses in critically ill patients have not linked sugar alcohols to significant cardiovascular risk, and that the pilot platelet effects may be temporary.²⁴

How to read the label

What to check on the Supplement Facts panel.

How to read the label

4 checks

Grams per piece, not just the word xylitol

The ear and cavity trials used about 5 to 10 g a day. Check the grams of xylitol per piece and multiply by the pieces you use in a day.^16,9

Other names

Xylitol may appear as birch sugar or wood sugar on labels, which matters most if you have a dog.⁴

The tooth-decay claim

US labels may say a sugar alcohol such as xylitol does not promote tooth decay; the rule forbids attributing any degree of risk reduction to the food.²

Toothpaste

The Cochrane benefit came from a fluoride toothpaste that also contained 10% xylitol. Xylitol toothpaste without fluoride was not what was tested.⁵

Have the bottle? Photograph its Supplement Facts panel and see each line, xylitol included, beside the doses and forms the trials used in Label X-Ray.

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

8 answers

Does xylitol reduce cavities?

Possibly, in children. Cochrane found low-quality evidence that fluoride toothpaste with 10% xylitol reduced cavities by 13% versus fluoride alone, and a 2024 review of 15 studies favoured xylitol, though most were at risk of bias. In adults at high risk, 5 g of lozenges a day for 33 months did not help significantly.^5,7,6

Does xylitol raise blood sugar?

Only slightly. In healthy men, 25 g had a glycaemic index of 7 compared with 100 for glucose, and a 50 g load had minimal effects on glucose and insulin.^21,22

Is xylitol safe for dogs?

No. FDA warns that xylitol can cause a dangerous drop in blood sugar in dogs within 10 to 60 minutes, and liver failure has been reported. Keep xylitol gum, mints, toothpaste and nut butters away from dogs, and call a vet or animal poison centre right away if a dog eats some.^4,28

Why does xylitol cause diarrhoea?

A large dose is not fully absorbed, and the rest reaches the colon, where gut bacteria ferment it. In a trial of young adults, 35 g and 50 g in a drink caused watery stools; xylitol caused more than erythritol at every dose.^31,1,20

Does xylitol interact with medicines?

We found no published drug interactions, so interaction data are limited. That is not proof that every combination is safe; mention large daily amounts to your pharmacist.

Can xylitol lower ear infections in children?

In healthy daycare children, yes, in Finnish trials: xylitol gum or syrup five times a day lowered ear infections from about 30% to 22%. It did not help when given three times a day, only during colds, or in children prone to ear infections, and a 2024 Canadian trial of syrup twice a day in 250 young children found no benefit.^14,17,18,33

Can I use xylitol during pregnancy?

A large trial in Malawi gave xylitol gum twice a day before and during pregnancy and found fewer preterm and low-birthweight births and fewer newborn deaths. It was one open-label trial in one country, so ask your midwife or doctor before relying on it.²⁷

Is xylitol linked to heart attacks?

A 2024 study found that people with the highest fasting blood xylitol had more heart attacks, strokes and deaths over 3 years, and a 30 g xylitol drink made platelets more reactive in 10 volunteers. It did not measure diet, the authors think the fasting levels mostly come from the body's own production, and the drink test had no control group, so it does not prove harm.^23,24

Sources

33 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

33 sources

1Xylitol's Health Benefits beyond Dental Health: A Comprehensive Review.Review Nutrients, 2019 · PMID 31390800
221 CFR 101.80 Health claims: dietary noncariogenic carbohydrate sweeteners and dental cariesGuideline Electronic Code of Federal Regulations, 2026 · ecfr.gov
3PubChem compound summary: Xylitol (CID 6912)Database National Library of Medicine, 2026 · pubchem.ncbi.nlm.nih.gov
4Paws Off Xylitol; It's Dangerous for Dogs (FDA consumer update)Safety communication U.S. Food and Drug Administration, 2025 · fda.gov
5Xylitol-containing products for preventing dental caries in children and adults.Meta-analysis Cochrane Database Syst Rev, 2015 · PMID 25809586
6Results from the Xylitol for Adult Caries Trial (X-ACT).RCT J Am Dent Assoc, 2013 · PMID 23283923
7Sugar substitutes on caries prevention in permanent teeth among children and adolescents: a systematic review and meta-analysis.Meta-analysis J Dent, 2024 · PMID 38762077
9Xylitol candies in caries prevention: results of a field study in Estonian children.RCT Community Dent Oral Epidemiol, 2000 · PMID 10830649
10Effect of erythritol and xylitol on dental caries prevention in children.RCT Caries Res, 2014 · PMID 24852946
11Effect of xylitol and xylitol-fluoride lozenges on approximal caries development in high-caries-risk children.RCT Int J Paediatr Dent, 2008 · PMID 18341562
12Cluster-randomized xylitol toothpaste trial for early childhood caries prevention.RCT J Dent Child (Chic), 2014 · PMID 24709430
13Xylitol gum and maternal transmission of mutans streptococci.RCT J Dent Res, 2010 · PMID 19948944
14Xylitol for preventing acute otitis media in children up to 12 years of age.Meta-analysis Cochrane Database Syst Rev, 2016 · PMID 27486835
15Xylitol chewing gum in prevention of acute otitis media: double blind randomised trial.RCT BMJ, 1996 · PMID 8916749
16A novel use of xylitol sugar in preventing acute otitis media.RCT Pediatrics, 1998 · PMID 9755259
17Failure of xylitol given three times a day for preventing acute otitis media.RCT Pediatr Infect Dis J, 2007 · PMID 17468653
18Xylitol syrup for the prevention of acute otitis media.RCT Pediatrics, 2014 · PMID 24394686
19Tolerability of oral xylitol solution in young children: implications for otitis media prophylaxis.RCT Int J Pediatr Otorhinolaryngol, 2007 · PMID 17097152
20Gastrointestinal tolerance of erythritol and xylitol ingested in a liquid.RCT Eur J Clin Nutr, 2007 · PMID 16988647
21Metabolic response to lactitol and xylitol in healthy men.Crossover RCT Am J Clin Nutr, 1997 · PMID 9094877
22Erythritol and xylitol differentially impact brain networks involved in appetite regulation in healthy volunteers.Crossover RCT Nutr Neurosci, 2022 · PMID 34404339
23Xylitol is prothrombotic and associated with cardiovascular risk.Observational Eur Heart J, 2024 · PMID 38842092
24Sweeteners: erythritol, xylitol and cardiovascular risk-friend or foe?Review Cardiovasc Res, 2025 · PMID 40444390
25Xylitol nasal irrigation in the management of chronic rhinosinusitis: a pilot study.Crossover RCT Laryngoscope, 2011 · PMID 21994147
26Effect of Postoperative Xylitol Nasal Irrigation on Patients with Sinonasal Diseases.Crossover RCT Otolaryngol Head Neck Surg, 2019 · PMID 30274540
27A cluster randomized trial of xylitol chewing gum for prevention of preterm birth: The PPaX trial.RCT Med (N Y), 2025 · PMID 39541971
28Xylitol Toxicosis in Dogs: An Update.Review Vet Clin North Am Small Anim Pract, 2018 · PMID 30064708
29Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs.Observational J Am Vet Med Assoc, 2006 · PMID 17014359
30Effects of xylitol and erythritol consumption on mutans streptococci and the oral microbiota: a systematic review.Systematic review Acta Odontol Scand, 2020 · PMID 32633595
31Oral and Systemic Effects of Xylitol Consumption.Review Caries Res, 2019 · PMID 31060040
32Xylitol: a review on bioproduction, application, health benefits, and related safety issues.Review Crit Rev Food Sci Nutr, 2015 · PMID 24915309
33Xylitol for the prevention of acute otitis media episodes in children aged 1-5 years: a randomised controlled trial.RCT Arch Dis Child, 2024 · PMID 37890960
34Role of Xylitol Nasal Irrigation in the Management of Chronic Sinusitis: A Systematic Review and Meta-Analysis.Meta-analysis Clin Otolaryngol, 2026 · PMID 41186273

What changed

Every dated change to this page: what changed, who made it and why.

Change log

2 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026evidence, key facts, heart findings, FAQ	Added the 2024 Canadian ear-infection trial of twice-daily syrup (PMID 37890960, no benefit) and a 2026 meta-analysis of xylitol nasal rinses (PMID 41186273). Reworded the 2024 cardiovascular study (PMID 38842092) to match its design: one fasting blood level with no diet data, which the authors attribute mainly to the body's own production, and a 30 g drink test with no control group. Trimmed the FAQ to eight questions; the dropped ones are answered in the evidence, forms and studied-doses chapters. Fact-checked against the sources; corrected: blood xylitol returned near baseline within 6 hours (the paper does not give 4 to 6 hours).	Writer: Kymata Health EditorialTrigger: A–Z page audit
Oct 19, 2026all	New page. Every PMID checked with NCBI E-utilities (esummary title, year and journal) and its abstract read with efetch. Regulatory facts read on eCFR (21 CFR 101.80 and 184.1835) and the FDA consumer update on xylitol and dogs on the date shown; chemical identity from PubChem. Grades follow the family rubric; the 2024 cardiovascular study is graded as observational evidence of possible harm.	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.