Chlorhexidine Mouthwash: How to Use & Adverse Effects

Written & Reviewed by Dr David Chen

This is a guide for the prescription only chlorhexidine mouthwash (CHX) with all of it’s technical specifications and things to know about it.

Below is a summary overview of this drug but click each one for more information.

Summary overview:

  • Description: Antiseptic oral rinse available by prescription only.
  • Ingredients: 1,1′-hexamethylene bis [5-(p-chlorophenyl) biguanide]di-D-gluconate, Water, Alcohol (11.6%), Glycerin, PEG-40, Sorbitan diisostearate, Flavor, Sodium saccharin, FD&C Blue No. 1
  • How to use: After breakfast and before bed, rinse with 15 ml undiluted for 30 seconds and then spit out.
  • Indications: Broadly used for various oral conditions (gum disease, etc).
  • Contraindications: Sensitivity, allergy, and those under 18 years old.
  • Pharmacology: Disrupts cell membranes and coagulates cytoplasmic proteins.
  • Warnings: Subgingival calculus increase and allergic reactions.
  • Precautions: Stains and taste alteration.
  • Adverse effects: Stains (teeth, tongue, restorations), taste alteration, allergies, ulcers, mucocele, stomatitis, glossitis, dry mouth, salivary gland swelling, etc.
  • Cost: Inexpensive (covered by insurance).
Chlorhexidine mouthwash


Chlorhexidine mouthwash (chlorhexidine gluconate 0.12% oral rinse) is an antiseptic rinse that is commonly prescribed by dentists. It is a simple and effective medication that can be used for a variety of oral conditions.

Drug facts:

  • Brand names – Peridex, Periogard, PerioRx, Perisol, Paroex, Oro Clense
  • Drug class – antiseptic & antibacterial
  • Availability – prescription only (not a controlled substance)
  • Dosage form – liquid solution
  • Cost – low cost

It works by reducing the number of bacteria in your mouth by killing them, preventing their grow, and reducing gum inflammation.


Chlorhexidine gluconate is a salt of chlorhexidine and gluconic acid. It is also a near neutral solution with a pH range of 5-7.

Chlorhexidine gluconate chemical structure
Chemical structure

Full list of ingredients:

  • 1,1′-hexamethylene bis [5-(p-chlorophenyl) biguanide]di-D-gluconate
  • Water
  • Alcohol (11.6%)
  • Glycerin
  • PEG-40
  • Sorbitan diisostearate
  • Flavor
  • Sodium saccharin
  • FD&C Blue No. 1
Chlorhexidine gluconate oral rinse description and ingredients
Description & Ingredients

This medicated oral rinse is technically colorless but it is often dyed with FD&C blue #1 which gives it its distinct blue color.

chlorhexidine rinse - blue colored liquid poured into cap
Chlorhexidine – Blue colored liquid

How to use

Ideally before you use the chlorhexidine oral rinse you should brush and floss your teeth. That way you have a clean mouth, tooth surfaces, and gums for the for the medicated rinse to work on.

Directions for use:

  1. Fill the cap to the “fill line” which is 15 mL or 1/2 oz.
  2. Swish around in mouth for 30 seconds undiluted.
  3. Spit out and do NOT rinse with water immediately afterwards to minimize medicinal taste.
  4. Do not eat or drink until lunch time if using in the morning.
  5. Use twice a day (after breakfast and before bed).
Chlorhexidine mouthwash - fill line on bottle cap
Fill line on cap

Who can use it

Chlorhexidine in mouthwash form is only recommended for adults age 18 and over. Children under the age of 18 should NOT use it because clinical effectiveness and safety has not yet been established.

How long to use it

You should use it for as long as you were directed by your dentist. Everyone’s condition is different and thus every treatment plan will differ. However, as a rule of thumb most dentists do not recommend using chlorhexidine rinse for longer than 2 weeks at a time.

If you miss a dose, please use it as soon as possible but if it is close to your next dose, just use it once. Do not double the amount or use it twice.


  • Do not refrigerate or freeze.
  • Throw away any unused CHX mouthwash after expiry date.
  • Keep out of reach from children.


Chlorhexidine mouthwash is broadly used in dentistry to treat a variety of dental conditions. Although most commonly you’ll be using it if you have a gum issue or after a deep cleaning.

Soft tissue uses:

Hard tissue uses:

  • Dry socket – may help reduce symptoms and help prevent it after extractions. This is especially important if you’ve had this condition before.
  • Root canal disinfectant.
  • Bacterial aerosolisation – reduces aerosolisation by 70-90%.

This medicated rinse is usually not the primary treatment for most conditions but is rather used as an adjunct. In other words, if you’re having a toothache it may help but probably won’t get rid of it completely.


Chlorhexidine rinse should not be used by any persons who is hypersensitive to CHX or allergic to it. If you’ve had a bad reaction to it in the past, please do not use. Those under the age of 18 also should not use this rinse unless explicitly directed by their doctor/dentist.

Drug interactions

There are no known drug to drug interactions with chlorhexidine rinse.

It is generally known as relatively safe to use due to its poor absorption across membranes.

  • Even if a large volume is accidentally ingested, it is poorly absorbed from the gastrointestinal tract.
  • Plasma levels of it are undetectable with normal use.


Chlorhexidine gluconate oral rinse is a cationic surfactant made of a synthetic biguanide. It has broad spectrum antibacterial, antifungal, and is even effective for COVID-19.

Mechanism of action:

  • It reduces bacterial load by disrupting cell membranes and coagulating cytoplasmic proteins. This kills them and prevents further growth.
  • Approximately 30% of CHX is retained in the mouth after rinsing.
  • It remains active in the mouth for up to 12 hours after use.
chlorhexidine gluconate oral rinse pharmacology

CHX mouthwash has very poor absorption across membranes so levels of it are typically undetectable in the plasma. Most of it is eliminated through feces (~90%) and less than 1% is excreted through urine.


The effect of chlorhexidine mouthwash on periodontitis has not yet been determined.

  • Increase of subgingival calculus was noted during clinical trials. This should be removed by a dentist or hygienist every 6 months.
  • Allergic reactions have been reported with overall chlorhexidine usage that is not exclusive to the oral rinse formulation.

The increase in tartar formation can be reduced and minimized with diligent oral hygiene. That means brushing twice a day with tartar control toothpaste and flossing your teeth before bed.


The three main precautions with using chlorhexidine rinse is the potential alteration of taste, potential oral staining and tartar build up.

  • Taste alteration. While using CHX, it may alter your taste perception for up to four hours after use. This side effect is temporary and it should go away if you discontinue use.
  • Staining. CHX is not a whitening mouthwash because it can cause brown discoloration on teeth, dental restorations (fillings), and even tongue staining.
  • Tartar formation. Studies have shown that when plaque is exposed to CHX, there is an increase in tartar formation due to increased uptake of calcium and phosphate.

Chlorhexidine rinse stains can be removed with professional dental cleanings but the appointment may require more time. Yes, the stains on teeth and on your tongue can be removed.

Pregnancy precautions

  • Pregnancy teratogenic effects – Pregnancy category B reproduction studies with rats demonstrated that doses up to 300 mg/kg/day and 40 mg/kg/day in rabbits showed no evidence of harm to the fetus. No human studies have been conducted.
  • Breastfeeding – it is unknown if CHX is excreted in milk but it is known that it is poorly absorbed through membranes.
  • Fertility – there is no evidence of impaired fertility in rats even with doses up to 100 mg/kg/day.

Adverse effects

Despite its wondrous benefits, use of chlorhexidine gluconate oral rinse does come with some adverse effects that may affect your mouth or well-being.

Side effects:

  • Teeth staining
  • Tartar formation
  • Tongue staining and geographic tongue
  • Dental restoration staining
  • Alteration of taste
  • Allergic reactions (itching, redness, analphylaxis)
  • Aphthous ulcers
  • Mucocele
  • Stomatitis and glossitis
  • Dry mouth
  • Salivary gland swelling

Please consult your dentist or physician about potential side effects. If you notice any, you may report side effects to the FDA at 1-800-FDA-1088.


Due to the poor gastrointestinal absorption of chlorhexidine, it is unlikely for harmful effects to occur even when swallowed accidentally.

However, the formulation does contain 11.6% alcohol so excessive swallowing may produce nausea, vomiting, and signs of drunkenness. These symptoms are no different than swallowing listerine mouthwash.

Inebriation is not pleasant but if a child ingests this accidentally, please seek medical help immediately. Children do not process nor tolerate ingesting alcohol the same way that adults do.


The cost for chlorhexidine mouthwash will vary depending on what insurance you have and the pharmacy that you go to. It is prescription only but it is relatively inexpensive and typically fully covered by most insurance plans.

However, if you shop for it online you can find pricings from $8-20 but you won’t be able to purchase it without a license or prescription.


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