What's the best mouthwash for bad breath? - How about toothpaste, gum, mints & lozenges?

- An overview of compounds proven to be effective in the treatment of halitosis. / Which mouth rinses contain them?

Page Graphics | Animations.
Link to types of oral rinses.
Link to how to use mouth rinse.
A note about effectiveness.

The chemical agents added to products like oral rinses, mints / lozenges, toothpaste and gum can be an important part of the treatment of bad breath. But only when they're used in conjunction with thorough mouth and tongue cleaning.

Despite whatever advertising you see, you can't expect any type of product to be an effective cure just on its own.

What's the best type of mouthwash to use for bad breath?

Before giving recommendations about specific types of mouthwash, it's important for you to understand what their different ingredients do. That way you can make an informed choice.

For the most part, the compounds added to oral rinses used to treat halitosis provide one of the following functions:

1) Antibacterial ingredients.

Since it's anaerobic bacteria living in your mouth that create the smelly compounds that cause bad breath, choosing an antibacterial mouthwash can reduce their numbers and therefore reduce oral malodor.

As we discuss below, look for rinses that contain these compounds: chlorhexidine, cetylpyridinium chloride.

2) Ingredients that affect volatile sulfur compound formation.

Selecting a mouthwash that degrades volatile sulfur compounds (VSC's), the smelly molecules that actually cause bad breath, can help to reduce breath odors.

As we discuss below, look for rinses that contain these compounds: chlorine dioxide (sodium chlorite), zinc.

The most effective mouthwash formulation.

Since each of the additives mentioned above functions via a different mechanism, the products that have performed best in research studies typically contain a combination of them (see "best to use" section below).

A bottle of mouthwash.

Remember- Mouthwash alone usually isn't a cure for halitosis.

Mouthwash additives proven to help to control bad breath -

1) Antibacterial compounds -

a) Chlorhexidine gluconate.

Properties: Antibacterial

Chlorhexidine gluconate is a broad-spectrum antibacterial compound. It's commonly used in dentistry in the treatment of gum disease. As a treatment for halitosis, it creates its effect by killing bacteria that produce smelly VSC's.

The most commonly used form of this compound is a 0.12% oral rinse (Peridex®, Perioguard®), available by prescription only.


In terms of effectiveness in treating bad breath, chlorhexidine is generally considered to be the gold standard of oral rinses. However, the side effects it creates complicates its use (see below).

Several studies have demonstrated that the use of a 0.2% chlorhexidine solution can produce a significant reduction in VSC levels for over 3 hours. The use of a 0.12% rinse tends to create a similar but more moderate effect, over the same time frame. (Cortelli 2008) [page references]

[See "best to use" section below for comparisons to other mouthwashes.]

Side effects.

Unfortunately, the use of chlorhexidine mouthwash creates noticeable side effects and for that reason should be used under the supervision of a dentist, especially when its long-term use is considered. Side effects include:

  • Temporary but noticeable staining of the user's tongue and teeth. A professional dental cleaning is typically needed to remove the discoloration from tooth surfaces.
  • The compound itself has a bad taste. It tends to alter the sense of taste of the user.
  • Beyond the above, extended use may result in tissue irritation.

(Fedorowicz 2008, Cortelli 2008)

b) Cetylpyridinium chloride.

Properties: Antibacterial

Cetylpyridinium chloride is an antibacterial compound that can help to reduce breath odors by way of helping to control the number of VSC-producing anaerobic bacteria found in a person's mouth.

Effectiveness as a mouthwash.

Studies suggest that the antibacterial affect of cetylpyridinium chloride isn't as robust as chlorhexidine's.

[Its effect on VSC levels was found to last for only 3 hours, as compared to 12 hours for chlorhexidine. However, simply rinsing with it more frequently throughout the day could help to overcome this deficiency.]

Possibly more importantly, research suggests that when combined with other compounds (specifically zinc alone, or in combination with chlorhexidine too) a synergistic (more effective) action is created.

(Fedorowicz 2008, Cortelli 2008)

[See "best to use" section below for comparisons to other mouthwashes.]

c) Essential oil preparations.

Properties: Antibacterial

Essential oil mouth rinses are typically composed of water/alcohol solutions of menthol, eucalyptol, thymol and/or methyl salicylate.

These products have a history in dentistry of being used in the treatment of gum disease. When used for that purpose or the treatment of halitosis, the basis of their effect is due to their antibacterial properties.

The most common form of this type of preparation is "antiseptic" mouthwash (i.e. Listerine® and its generic equivalents).

Effectiveness as a mouthwash.

Studies suggest that:

  • The initial effect (first 60 minutes) of using this type of preparation is simply re-odorization, meaning the essential oils act as masking agents that just cover over the person's bad breath.
  • At post treatment times of 2 to 3 hours, the anti-ordor activity of these products is more likely due to their antibacterial action.
  • Long term use of an essential oil rinse can help to maintain reduced levels of VSC producing bacteria, both in dental plaque and in the coating that builds up on the tongue.

(Cortelli 2008)

[See "best to use" section below for comparisons to other mouthwashes.]


This type of mouthwash may not make the best choice for treating bad breath because these preparations typically contain a high level of alcohol (on the order of 25%). Since alcohol acts as a desiccant, it creates a drying effect on oral tissues which may ultimately contribute to a person's breath problems. (Read here for more details.)

2) Compounds added to mouthwashes to affect VSC formation. -

a) Chlorine dioxide (or sodium chlorite).

Properties: Affects Volatile Sulfur Compound Formation

Chlorine dioxide (ClO2) is an oxidizing agent that's been shown to degrade sulfur-based amino acids. Since these are the building blocks of the volatile sulfur compounds that cause bad breath, when fewer of them are available, fewer VSC's will be formed.

There seems to be no shortage of these types of rinses, or advertising hype to go along with them. Some mouthwashes are formulated with sodium chlorite as the active ingredient, which then breaks down to release chlorine dioxide.


As we discuss below, combination mouthwashes (such as chlorine dioxide + zinc) are likely more effective than the use of either component alone.

[See "best to use" section below for comparisons to other mouthwashes.]

b) Zinc.

Properties: Affects Volatile Sulfur Compound Formation

Metal ions (such as zinc, sodium, tin, copper, and magnesium) have the ability to oxidize (react with) the thiol (sulfur based) molecule groups found on the precursor components of VSC's. (Cortelli 2008)

(FYI: Thiol's are the smelly compounds added to natural gas to give it its stinky smell.)

Effectiveness as a mouthwash.

Zinc is the metal of choice for rinses used to treat bad breath. Not because it's the most effective one (copper is) but because it provides a benefit yet has low toxicity and does not create tooth staining (like other metals can, especially tin and copper).

  • Studies have shown that 1% zinc acetate mouthwash has a significant effect on VSC levels, even 3 hours after use. (Cortelli 2008)
  • It's common for a rinse to include zinc as just one of its active ingredients (combination treatment).
Side effects.

The use of a mouthwash that contains zinc may result in a metallic taste or odor. Products that include it frequently contain masking agents to help overcome this difficulty.

Which is the best mouthwash to use?

If you're looking for hard scientific evidence about which mouthwash brand or product makes the best choice for treating bad breath, you'll be disappointed.

There's no shortage of low-quality information.

When creating this page, we leaned heavily on the findings of The Cochrane Collaboration's review of mouth rinses for treating halitosis conducted by Fedorowicz (2008).

That's because the papers published by this organization characteristically take the form of a literature review, where stringent standards have been set that the research papers selected for inclusion must meet. For their oral rinses report:

  • The authors identified 555 research publications to evaluate. But only 5 of them met the standards that were set.
  • The paper actually states: "... although there have been a large number of studies conducted over the last 30 years, it was somewhat surprising to find so few high quality randomised controlled trials ...".

Whether the design shortfalls of most studies is purposeful (so to create a bias for a manufacturer's product), or is due to other factors, is open to conjecture. But bottom line, and despite what advertising claims may be made, the findings of most studies on this subject are quite open to debate.

Which types of mouthwash did the Cochrane Collaboration consider the best?

Per the Cochrane review about treating halitosis with oral rinses (Fedorowicz 2008), we can state that:

  • Picking a product that takes a combination approach seems to make the best choice.
  • That means selecting a product that contains both ingredients that are antibacterial (chlorhexidine, cetylpyridinium chloride) and disrupt VSC formation (chlorine dioxide, zinc).

a) Which rinse had the most convincing evidence?

The Fedorowicz review stated that the most compelling evidence they found supported the use of a mouthwash that contained the ingredients (0.05%) chlorhexidine + (0.05%) cetylpyridinium chloride + (0.14%) zinc lactate.

[Blom (2012), another review paper that set strict standards for the studies it considered, concurred with this opinion.]

What product is this?

Our search of the web only identified one rinse that had that exact formulation (Halita®). It's manufactured by Dentaid, headquartered in Spain. On their website we could not identify a USA distributor.

It's important to note that the use of this product (like any containing the ingredient chlorhexidine) resulted in the formation of tooth staining and tongue discoloration. Even if available, this product should be used with your dentist's supervision.

b) What other rinses were found to be effective?

The following studies (that met the Cochrane Collaborations review's standards) provided the following information.

Borden (2002)

This study found that a rinse containing cetylpyridinium chloride + zinc (BreathRx®) was more effective in reducing breath malodor and VSC levels than an essential oils preparation (Listerine®) and a chlorine dioxide + zinc mouthwash (Oxygene®).

Codpilly 2004

In contrast to Borden, Codpilly found sodium chloride (chlorine dioxide) + zinc mouthwash (TriOral®) to be more effective than a cetylpyridinium chloride + zinc rinse (BreathRx®).

Kozlovsky (1996)

This older study confirmed that cetylpyridinium chloride mouthwashes are more effective than essential oils (Listerine®).

Our conclusions.

From the above studies, it seems you could conclude that there's no overwhelming evidence that favors the use of chlorine dioxide + zinc mouthwashes vs. cetylpyridinium chloride + zinc ones. But both of these are more effective than the use of essential oils preparations (Listerine®).

Mouth rinses for bad breath and their active ingredients.

We've done our best to organize the following list. But we'll leave it to the reader to confirm this information when making their purchase. If you have information to share, please leave it as a comment below.

And, of course, in all cases the manufacturer's instructions and recommendations must be followed when using these products.

  • Peridex®, Perioguard®, Paroex® - chlorhexidine gluconate
  • Perio-Aid® - chlorhexidine + cetylpyridinium chloride
  • Halita® - chlorhexidine + cetylpyridinium chloride + zinc lactate
  • Listerine®, ("antiseptic" mouthwash) - essential oils
  • Breath Rx® - cetylpyridinium chloride + zinc + essential oils
  • Crest Pro-Health®, Scope®, Cepacol® - cetylpyridinium chloride
  • Oxygene® - chlorine dioxide + zinc
  • TriOral®, SmartMouth® - sodium chlorite + zinc chloride
  • CloSYS®, ProFresh®, TheraBreath®, DioxiCare® - chlorine dioxide

How to use mouthwash so you get the most benefit from it.

1) When should you rinse?

As a general rule, you'll get the most out of using an oral rinse if you use it after you have brushed and flossed your teeth and cleaned your tongue. Here's why.

  • It's difficult for rinses to penetrate oral films (plaque that has built up on and around a person's teeth, gums and tongue).
  • As a result, the bacteria (and their waste byproducts) situated in deep within it go largely unaffected.

By rinsing after you have cleaned your mouth, that plaque that still remains will at least have been disrupted and exposed. As a result, it will be more easily penetrated and therefore more vulnerable to the actions of the compounds found in the rinse you are using.

Halitosis is usually caused by plaque accumulation on the back part of the tongue.

Why you need to gargle as far back as possible.

2) Gargling.

When you use a rinse, it's best to gargle it.

When a person gargles, they should make an "aaahhh" sound. This extends their tongue outward and allows the mouthwash to contact a greater percentage of its posterior region (the area that usually harbors the greatest number of odor producing bacteria.

Note: All mouth rinses should be spit out after gargling. Children should not be given mouthwash because of the possibility that they may swallow it.

3) Swishing.

Besides just focusing on your tongue, you should also swish mouthwash around in your mouth (especially between your teeth) so it can have an affect on the bacterial components located there.

Products other than mouthwash that can be useful in the treatment of bad breath.

a) Breath mints / Lozenges.

Just like with mouth rinses, using breath mints, lozenges, drops or sprays on their own are usually not an effective cure for bad breath. But when used in conjunction with tongue cleaning and tooth brushing and flossing, they can be valuable adjuncts.

  • Look for products that contain the exact same agents we discuss above. Especially those that have the ability to neutralize volatile sulfur compounds such as chlorine dioxide, sodium chlorite, and zinc.
  • If you don't see those kinds of ingredients, it's quite likely that the product you're considering has no real effect toward curing the underlying fundamental causes of halitosis but instead just contains flavorings and perfumes used to temporarily mask over oral malodor.
Additional benefits.

When mints or lozenges are used they stimulate the flow of saliva. This action creates a cleansing and diluting effect, both on oral bacteria and the smelly VSC byproducts they create.

b) Toothpaste.

Triclosan, an antibacterial agent sometimes added to toothpaste, can reduce the level of smelly VSC's in a person's breath by way of helping to reduce the number of bacteria that produce them. (Vazquez 2005)


A study performed by Sharma (2007) compared the use of two toothpastes, one of which contained triclosan (Colgate Total).

  • At 12 hours following use, testing showed that the use of both pastes produced an effect that reduced VSC levels.
  • But at this point, the VSC levels of subjects that had used the non-triclosan dentrifice had edged above the threshold value of what's generally considered to be unpleasant breath odor, while the levels of the subjects that had used the triclosan paste still remained below.
  • Previous studies had found a similar type of benefit.
Issues and concerns.

The use of products that contain triclosan is controversial. The website of the US FDA discusses this issue.

c) Chewing gum.

As mentioned above, just the act of having something in your mouth, like chewing gum, can help to decrease halitosis. That's because as you chew your body tends to produce more saliva.

This increase in saliva helps to dilute and wash away the smelly volatile sulfur compounds that cause bad breath. That means this effect isn't a true cure for halitosis, it's just a temporary remedy.


Rosing (2009) evaluated VSC levels after test subjects chewed gum , both a regular one and a sugar-free one that also contained zinc.

  • The use of both gums produced a reduction in VSC levels, even out to 60 minutes after chewing (60 minutes was the point after no further testing was done).

The authors of the paper concluded that the lack of difference between the two suggested that the act of chewing, and the increase in saliva production it produced, was more important than the actual components of the gum.

Our next page talks about cures for denture breath. Or jump ahead to our halitosis FYI page, just to make sure you didn't miss anything we covered on our previous pages (see Topic Index below).



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