Pooled evidence from nine included studies is inconclusive regarding whether antibacterial mouthwash use significantly increases blood pressure in humans, with five studies finding significant elevations and four finding no significant relationship.
Key Findings
Results
A scoping review of nine studies found mixed results on whether antibacterial mouthwash use increases blood pressure in humans.
51 studies were initially retrieved from PubMed and Scopus searches, and after independent screening by two reviewers, nine studies were included.
Five of the nine studies found significant blood pressure elevations after mouthwash usage.
Four of the nine studies found no significant relationship between antibacterial mouthwash use and blood pressure.
The authors concluded that 'no firm conclusions can be drawn regarding the effect of antibacterial mouthwash on blood pressure at this time.'
Methods
The nine included studies spanned multiple study designs, including randomized and nonrandomized crossover trials, an active-controlled trial, and an observational study.
Four studies were randomized crossover trials.
Three studies were nonrandomized crossover trials.
One study was an active-controlled trial.
One study was an observational study.
Inclusion criteria required primary research articles published since 2014 that analyzed blood pressure changes in human adults after using antibacterial mouthwash.
Results
The included studies were rated as being of good quality based on a modified Downs and Black assessment checklist.
Mean modified Downs and Black score was 21.9 ± 2.9 out of 28 points.
Two independent reviewers extracted data on study methodology, sample size, participant characteristics, type of mouthwash, mouthwash regimen, and study results.
Despite overall good quality ratings, methodological weaknesses were noted in some studies, including inadequate washout periods and lack of randomization.
Results
Heterogeneity across studies was identified as a key reason the pooled evidence is inconclusive.
Sources of heterogeneity included differences in intervention lengths, mouthwash composition, participant characteristics, and blood-pressure assessment schedules.
Methodological weaknesses such as inadequate washout periods and lack of randomization in some studies further limited the ability to draw conclusions.
The authors describe the overall evidence as 'inconclusive' due to these combined factors.
Background
Antibacterial mouthwashes have a plausible biological mechanism for raising blood pressure by killing oral nitrate-reducing bacteria and impairing nitric oxide production.
Nitric oxide is described as 'a key molecule in vasodilation and blood pressure regulation, often acting as a mediator.'
Search terms used in the review included 'mouthwash,' 'chlorhexidine,' 'antibacterial,' 'salivary nitrite,' 'nitrate,' and MeSH terms such as 'blood pressure' and 'hypertension,' reflecting this mechanistic focus.
Approximately 36% of United States adults use mouthwash daily, indicating a potentially large population exposure.
Conclusions
The authors recommend future research using larger randomized trials with standard washout periods and long-term monitoring to clarify the relationship.
Future research should 'utilize larger, randomized trials with standard washout periods and long-term monitoring.'
The call for standardization addresses the heterogeneity in intervention lengths, mouthwash composition, and blood-pressure assessment schedules identified across the nine included studies.
Studies with pediatric participants, animal studies, reviews, or studies that did not measure blood pressure changes were excluded from this review.
What This Means
This research suggests that there may be a connection between using antibacterial mouthwash and changes in blood pressure, but the current scientific evidence is too mixed to draw firm conclusions. The review looked at nine studies examining whether antibacterial mouthwashes — which kill bacteria in the mouth that help the body produce nitric oxide, a chemical that relaxes blood vessels — might raise blood pressure as a result. Five of the nine studies did find that antibacterial mouthwash use was associated with higher blood pressure, while four found no meaningful effect.
The difficulty in reaching a clear answer comes down to the wide variation in how these studies were conducted. They used different types of mouthwash, had participants use mouthwash for different lengths of time, measured blood pressure at different points, and studied different types of people. Some studies also had methodological limitations, such as not allowing enough time between treatment periods for the body to return to its normal state. These differences make it hard to compare studies or combine their results into a single definitive answer.
This research matters because roughly 36% of American adults use mouthwash daily, meaning a very large number of people could potentially be affected if there is a real relationship between antibacterial mouthwash and blood pressure. The authors call for larger, well-designed studies that use consistent methods and track participants over a longer period of time to settle this question. Until then, the impact of regular antibacterial mouthwash use on blood pressure remains an open scientific question.
Singh B, North P, Rushetsky Z, Brito R, Jenney F. (2026). The effect of antibacterial mouthwash on blood pressure in humans: a scoping review.. BMC cardiovascular disorders. https://doi.org/10.1186/s12872-026-06572-4