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Is Listerine Safe? The Truth About the Classic Mouthwash

📅 Updated February 2026⏱️ 4 min readNEW

TL;DR

Classic alcohol-based Listerine is a hard pass. Recent studies show it disrupts the oral microbiome, kills beneficial bacteria needed for healthy blood pressure, and actually increases bacteria linked to gum disease and certain cancers. Even their alcohol-free versions rely on harsh detergents and artificial dyes.

🔑 Key Findings

1

Daily use of Listerine Cool Mint was shown to increase bacteria linked to colorectal and esophageal cancers in a 2024 study.

2

Classic Listerine contains up to 26.9% alcohol, which severely dries out the mouth and destroys the oral microbiome.

3

Listerine decreases Actinobacteria, a beneficial bacteria necessary for producing nitric oxide to regulate blood pressure.

4

The formula relies on Poloxamer 407, a synthetic detergent, alongside artificial dyes and sweeteners.

The Short Answer

Classic alcohol-based Listerine is one of the worst things you can put in your mouth daily. At up to 26.9% alcohol, it acts like a nuclear bomb on your oral ecosystem, destroying both the germs that cause bad breath and the beneficial bacteria your body desperately needs. Does Mouthwash Kill Good Bacteria

Even worse, a 2024 study found that daily use actually increases bacteria linked to gum disease and cancer. If you want fresh breath, there are much safer ways to get it. Safest Mouthwash

Why This Matters

Your mouth is a delicate ecosystem of bacteria that protects your teeth and overall health. When you use harsh antiseptics, you destroy the good bugs that keep pathogens in check. Is Mouthwash Safe

One crucial job of these good bacteria is producing nitric oxide, which helps keep your blood vessels dilated. Studies show that killing off these oral bacteria can actually increase your blood pressure. Is Mouthwash Bad For Blood Pressure

The cancer connection is also impossible to ignore. A 2024 peer-reviewed study revealed that daily Listerine use increased the abundance of Fusobacterium nucleatum—a bacteria strongly associated with colorectal and esophageal cancers. Is Alcohol In Mouthwash Bad This exact finding sparked a massive 2024 class-action lawsuit against Listerine's parent companies.

What's Actually In Listerine

  • Alcohol (21.6% - 26.9%) — A massive dose of ethanol that severely dries out the mouth and disrupts the entire oral microbiome. Alcohol Vs Alcohol Free Mouthwash
  • Poloxamer 407 — A synthetic detergent used to mix essential oils with water. Animal studies link high doses of this emulsifier to severe cholesterol and lipid disruptions.
  • Sodium Saccharin — An artificial sweetener added to mask the harsh chemical taste that provides zero oral health benefits.
  • Green 3 & Yellow 10 — Synthetic petroleum-based dyes. These are added purely for marketing purposes so the liquid looks artificially "minty."
  • Essential Oils (Eucalyptol, Menthol, Thymol) — While naturally derived, these are heavily concentrated to act as strong antimicrobial agents that can be incredibly harsh on sensitive oral tissues.

What to Look For

Green Flags:

  • Dead Sea Salt — Naturally mineralizes teeth and gently neutralizes bad breath without destroying the microbiome.
  • Aloe Vera — Soothes the gums and helps maintain healthy moisture levels in the mouth.

Red Flags:

  • High Alcohol Content — Anything above 0% is unnecessarily drying and highly disruptive to oral flora.
  • Artificial Dyes — Blue 1, Green 3, and Yellow 5 serve no health purpose and are linked to behavioral and cellular concerns.

The Best Options

Skip the harsh antiseptics and choose formulas that balance your oral microbiome. Safest Mouthwash

BrandProductVerdictWhy
LumineuxOral Essentials MouthwashUses Dead Sea salt and essential oils without alcohol.
TheraBreathFresh Breath Oral Rinse⚠️Alcohol-free, but still uses some synthetic compounds.
ListerineCool Mint Antiseptic🚫Contains 21.6% alcohol and increases cancer-linked bacteria.

The Bottom Line

1. Ditch the alcohol. The 21%+ alcohol content in classic Listerine dries out your mouth and destroys beneficial bacteria.

2. Protect your microbiome. Your mouth needs good bacteria to produce nitric oxide, which is essential for healthy blood pressure.

3. Switch to gentle alternatives. Look for salt-based formulas or try traditional practices like coconut oil swishing. Is Oil Pulling Better Than Mouthwash

FAQ

Is Listerine Zero Alcohol safe?

It's better than the classic version, but it still contains synthetic dyes, artificial sweeteners, and harsh detergents like Poloxamer 407. You're better off with a truly clean formula. Safest Mouthwash

Does Listerine cause cancer?

A 2024 study found that daily use increases the abundance of specific oral bacteria linked to colorectal and esophageal cancers. While the mouthwash itself isn't a proven carcinogen, it creates a bacterial imbalance that raises serious red flags.

What should I use instead of Listerine?

Dentists increasingly recommend salt-based rinses or hydroxyapatite-infused mouthwashes that support the oral microbiome instead of destroying it. Another great natural option is a daily oil pulling routine. Does Oil Pulling Work


References (10)
  1. 1. milberg.com
  2. 2. newbeauty.com
  3. 3. hawthorneastdental.com.au
  4. 4. nih.gov
  5. 5. ericdavisdental.com
  6. 6. injuryclaims.com
  7. 7. medboundtimes.com
  8. 8. askthedentist.com
  9. 9. classaction.org
  10. 10. wikipedia.org

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