Dentist shares real reason you should flush your mouthwash down the toilet: 'Double risk of high blood pressure...'

California-based dentist Dr Mark Burhenne advocates a shift towards oral‑care practices that protect the microbiome rather than eradicate it.

For decades, a stinging swish of minty mouthwash has been the gold standard of oral hygiene. But according to a California-based dental expert, that morning ritual might be doing more harm than good — specifically for your heart and metabolic health.

In a warning shared on December 28, 2025, San Francisco dentist Dr Mark Burhenne urged people to reconsider their use of antiseptic mouthwashes. His advice was blunt: “In your 30s, your cardiologist will tell you to pour your mouthwash down the toilet. It is very important that you take this advice seriously.”

The nitric oxide connection

The core of Dr Burhenne’s warning lay in the delicate ecosystem of the mouth. While we are taught to view all bacteria as 'germs' to be eradicated, our tongues host beneficial microbes that play a critical role in cardiovascular health.

These specific bacteria, Dr Burhenne explained, are responsible for producing roughly 50 percent of the body’s nitric oxide. He said, “No bacteria = no nitric oxide = your blood pressure skyrockets. If we neglect the mouth - it harms not only the heart but the rest of the body too…”

When powerful antiseptic mouthwashes 'nuke' the oral microbiome – they don't just kill the bacteria that cause bad breath, they eliminate the biological factories that help regulate blood flow and vascular health, Dr Burhenne shared.

Alarming risks: diabetes to hypertension

To back his claims, Dr Burhenne cited a three-year study that highlighted the systemic dangers of over-using mouthwash. The data suggests that the habit of swishing mouthwash twice a day was linked to: higher risk of diabetes, and nearly double the risk of high blood pressure.

He said: “I’m a dentist and I would never use mouthwash twice a day. Here’s what a 3-year study found: 49 percent higher diabetes risk. Nearly double the risk of high blood pressure. The reason is mouthwash kills the bacteria on your tongue that produce 50 percent of your body’s nitric oxide — the molecule that keeps blood vessels flexible.”

A holistic view of health

Dr Burhenne’s warning reflected a growing movement in 'functional dentistry', which views the mouth not as an isolated area, but as the gateway to the rest of the body. “If we neglect the mouth — or treat it with harsh chemicals — it harms not only the heart but the rest of the body too,” he said. Therefore, the takeaway is not necessarily to abandon oral hygiene, but to pivot toward methods that support the oral microbiome rather than destroying it.

Note to readers: This report is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.

This article is for informational purposes only and not a substitute for professional medical advice.