Twice-a-Day Mouthwash and Blood Pressure: What One Study Found About Oral Bacteria
Breath & MouthArticleSome mouth bacteria help the body make nitric oxide, which relaxes blood vessels, and antibacterial mouthwash can knock them back. In a study of overweight adults aged 40 to 65, people who used over-the-counter mouthwash twice a day or more were about twice as likely to develop high blood pressure over three years. It's a link, not proof.
Some bacteria on your tongue and in your mouth turn nitrate from food into compounds your body uses to make nitric oxide, which matters for heart and metabolic health.12 Short-term trials show antibacterial mouthwash can reduce these bacteria and lower nitric oxide levels.1 So researchers asked whether routine mouthwash use affects blood pressure.
What the study found
In Puerto Rico, 540 overweight or obese adults aged 40 to 65 without high blood pressure were followed for about three years.1
- 12% developed high blood pressure.1
- People who used over-the-counter mouthwash twice a day or more had about 1.85 times the rate of less frequent users and 2.2 times the rate of non-users.1
- The link held after accounting for age, smoking, activity, waist size, alcohol, blood sugar and other factors, and among never-smokers.1
- A single blood pressure reading at one visit didn’t show the same link.1
A later review noted that long-term mouthwash use has been linked to higher blood pressure and higher risk of prediabetes and diabetes.2
What it can’t prove
This was an observational study in one group of overweight adults, using self-reported diagnoses.1 It can’t show mouthwash caused high blood pressure. People who use a lot of mouthwash may differ in other ways.
What this means for you
- Don’t rely on mouthwash for bad breath. Our guide to whether mouthwash fixes bad breath explains causes worth treating instead.
- Brushing, flossing and tongue cleaning may favor helpful bacteria, according to the review.2 See tongue scrapers.
- Use prescription rinses as directed. See chlorhexidine mistakes.
- If you have high blood pressure, mention how often you use mouthwash.
Our articles on blood pressure pill timing and gum disease and the heart cover related questions.
Try: “I use mouthwash twice a day out of habit. Is that necessary for my gums, or should I cut back given my blood pressure?”
Is It My Breath? includes a visit script. Use it to list the mouth products you use daily before your dental visit.
This article is for general educational purposes only and is not medical or dental advice. It isn't a substitute for diagnosis or treatment from a qualified healthcare professional who knows your health history. Please don't stop a prescription mouth rinse, such as one prescribed after gum surgery, without asking your dentist. A blood pressure reading of 180/120 or higher with chest pain, shortness of breath, weakness or trouble speaking needs emergency care. If you think you may be having a medical emergency, call 911 or your local emergency number right away. This article discusses observational research. Girl Playbook does not endorse any specific product, test, or provider.
Girl Playbook sells this book. It provides education and worksheets, not individualized medical care.
Sources
The research behind this article, in the order it’s cited. How we source our articles.
- Blood Pressure (full text via PubMed Central), 2020Over-the-counter mouthwash use, nitric oxide and hypertension risk (opens in a new tab)abcdefgh
- Journal of Dental Research (full text via PubMed Central), 2022Pathways Linking Oral Bacteria, Nitric Oxide Metabolism, and Health (opens in a new tab)abc
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