Halitosis Hysteria: Mouthwash Is Not Hygiene — How a 1920s Marketing Campaign Created a Modern Epidemic

What if the mouthwash you use to feel cleaner is changing far more than your breath? For nearly a century, we have been taught that a “clean” mouth is a chemically sanitized mouth. But the human mouth is not sterile — and it was never designed to be.

Halitosis Hysteria investigates the history, biology, and science behind one of the most routine products in the modern bathroom. The story begins in the 1920s, when an obscure medical term — halitosis — was transformed into a powerful consumer fear.

Your tongue hosts bacteria that take part in the enterosalivary nitrate–nitrite–nitric oxide pathway, helping convert dietary nitrate into molecules involved in vascular signaling. Throughout the book, Evidence Check sections separate strong human evidence from observational associations and mechanistic hypotheses.