Chlorhexidine (CHX) vs COVID-19

April 1, 2020 7:16 pm Published by

This document was initially written on March 21 2020. It became the source of a final paper that may be found in the subsequent blog entitled An Antiviral Antiseptic Gargle & Nasal Spray May Help Healthy People Avoid Coronavirus Infection.

Centers For Disease Control (CDC) SUBMISSION: COVID-19 and Chlorhexidine Gluconate (CHX) – help “flatten the curve”

The author has no financial interest in the information presented and is not selling any associated product nor service. Dr. Dorfman retired and closed his private practice in 2019.

Dr. Jeffrey Dorfman
1dentist, LLC
New York


The intention of this literature review is to suggest the value of independent controlled studies of CHX vs COVID-19. Let’s help “flatten the curve.” COVID-19 vaccines can take months or years. And there is a desperate shortage of face masks. In contrast these CHX products already exist in stores. Controlled tests of this idea can be accomplished via public-private partnerships in weeks. The suggestion is simply an off-label use and method.

Please forward this to the decision-makers in the City, State & Federal government. We need clinical trials now to confirm CHX can help reduce COVID-19 infection in non-infected people.


  1. Prescription mouthwashes containing Chlorhexidine (CHX) have been readily available in the U.S. for over three decades to treat gum disease. CHX is also the active ingredient in Hibiclens, the highly-regarded skin cleanser, used by doctors around the world for decades.
  2. Chlorhexidine may help reduce new infection rates among healthy people (flatten the curve). It is not suggested to use CHX in those already infected to prevent contagion.
  3. Consider CHX oral rinse to gargle in the back of the throat & using Q-tips to coat the nostrils for prevention. In contrast, normal use is to rinse in the front of the mouth around the teeth.
  4. CHX exhibits unique substantivity (stickiness) even in the mouth so normal dosage is only twice a day. In contrast, the efficacy of “preprocedural” oxidative mouthrinses (e.g. 1% hydrogen peroxide or 0.2% Povidone-Iodine) that are used before a dental procedure do not make claims on how long they remain in the mouth after application. CHX remains in the mouth for 12 hours. Generally avoid using toothpaste for at least 30 minutes before using CHX bc some toothpaste ingredients interact and reduce the effectiveness of CHX.
  5. CHX use is low-risk, it’s cheap and readily available in stores.
  6. Current CHX manufacturers include: 3M (Peridex), Colgate (PerioGard) & GUM (Paroex).
  7. An ideal CHX concentration between the 0.12% oral rinse and 4% skin cleanser should be investigated. Many current articles confuse the CHX concentration used for disinfection on inanimate surfaces vs antiseptic use in the body. Statements regarding the efficacy of CHX vs COVID-19 must include the % concentration.
  8. The author is focused on the use of an antiviral antiseptic to preventively line the mouth, throat and nostrils to help prevent COVID-19 infection in healthy adults. He believes CHX currently offers the best choice however other antiseptics may also prove beneficial.

Chlorhexidine (CHX) Oral Rinse is readily available and should be considered by the CDC for preventive use by the general population to flatten the curve of COVID-19 infection. The oral rinse can be gargled in the back of the throat twice daily as typically indicated or the frequency could be increased. Q-tips moistened with Chlorhexidine could also be swabbed inside the nostrils. The chlorhexidine oral rinse exhibits significant substantivity so that it remains on surfaces longer than expected. Collectively this could create the first barriers to COVID-19 entering the body. Can chlorhexidine in the mouth, back of the throat and nostrils help prevent the virus, being transmitted from others, from entering the lungs of a healthy person? CHX has a quick kill rate.

Chlorhexidine likely kills COVID-19 because it kills other envelope viruses like H5N1 (bird flu), H1N1 (swine flu)  and H3N2 (influenza virus). It also appears Chlorhexidine is effective in reducing Ventilator-Associated Pneumonia (VAP). However some consideration on the efficacy of chlorhexidine NOT killing COVID is based upon the wrong concentration of 0.02% used to clean inanimate surfaces (disinfectant) vs 0.12% found in Rx oral rinses or 4% found in Hibiclens skin cleanser (antiseptic). This error appears to be common in the literature (see third reference below). An antiseptic is applied to the body whereas a disinfectant is applied to nonliving surfaces. CHX can be used as both an antiseptic or disinfectant depending upon concentration.

An ideal CHX concentration between the 0.12% oral rinse and 4% skin cleanser should be investigated by the CDC. It appears that a minimum chlorhexidine concentration of 2% is needed to kill VAP in vivo. CHX may be considered toxic like bleach however it can be used on the skin and in the body whereas bleach cannot. CHX is not an antibiotic so therefore it can kill more organisms. CHX is a common contact allergen that can cause a rash, difficulty breathing or an anaphylactic reaction and death (rare). Allergy testing is available. It is not recommended for people under age 18 and during pregnancy. CHX can also reversibly stain teeth (common). It also affects how food tastes bc it remains in your mouth (substantivity) much longer than regular mouthwashes (common).


Penn Dental Dean Mark Wolff DDS, PhD, former Arizona School of Dentistry Dean Jack Dillenberg and NYU Dental Professor of Oral Pathology Ross Kerr agree the idea is worth sending to the CDC. MAJ Brandon Jones, DDS, MS, US Army Dental Corps believes this idea is “interesting” and “encouraging.” R. Ivan Lugo, DDS, former CEO, The Hispanic Dental Association, believes this idea is worthy of clinical trials. The NYS Dental Association has requested this literature review to disseminate information to members.

Current CHX manufacturers include: 3M (Peridex), Colgate (PerioGard) & GUM (Paroex). There is very little risk, it’s cheap and readily available in stores.

Note: Anyone considering use of Chlorhexidine should directly consult with their dentist or physician before use. This document is solely intended for professional discussion. It is not intended for personal advice.

The author has no commercial interest in this submission.


March 12, 2020

DermSafe has both an immediate kill as well as a long term kill for up to 4 hours on envelope viruses tested including H5N1 (bird flu), H1N1 (swine flu)  and H3N2 (influenza virus). Although we have not tested against the Coronavirus (COVID-19) it is also an envelope virus.

In vitro virucidal effectiveness of a 0.12%-chlorhexidine gluconate mouthrinse.

J Dent Res. 1990 Mar;69(3):874-6

The purpose of this work was to assess the in vitro antiviral effectiveness of a mouthrinse (Peridex) containing 0.12% chlorhexidine gluconate (CH) on several viruses that are associated with the oral cavity. These included herpes simplex virus (HSV), cytomegalovirus (CMV), influenza A, parainfluenza, polio, and hepatitis B (HBV). Virucidal assays in tissue cultures were performed on all viruses except HBV. The virucidal effect on HBV was assessed by inactivation of the DNA polymerase contained within the Dane particle of HBV. The CH mouthrinse had virucidal activity against all of the viruses, except polio, in as little as 30 s. The virucidal activity increased with time. However, there were differences in the responses of these viruses to the challenge of the CH mouthrinse, probably due to subtle differences in the physical/chemical structures of the virus envelopes. Results on DNA polymerase of the HBV virus were similar to those on the other viruses, except polio, suggesting a common mechanism. With respect to this mechanism, it was proposed that CH exerted its antiviral effect on the envelopes of these viruses, and that the absence of an envelope on polio precluded effectiveness against this virus. – CHX as a disinfectant vs antiseptic confusion

Thus, SARS-CoV-2 belongs to the betaCoVs category. It has round or elliptic and often pleomorphic form, and a diameter of approximately 60–140 nm. Like other CoVs, it is sensitive to ultraviolet rays and heat. Furthermore, these viruses can be effectively inactivated by lipid solvents including ether (75%), ethanol, chlorine-containing disinfectant, peroxyacetic acid and chloroform except for chlorhexidine. % concentration is not mentioned!


* Prevention Strategies for Periodontal Diseases

BECKY DeSPAIN EDEN, in Prevention in Clinical Oral Health Care, 2008

Chlorhexidine gluconate is the most effective antiplaque agent currently approved. Chlorhexidine is a broad-spectrum antiseptic that is bactericidal and effective against some yeasts and viruses.53 The efficacy of chlorhexidine stems from its ability to bind to oral tissues and slow release into the oral cavity. This characteristic, known as substantivity, provides a continued inhibitory effect on plaque formation for 12 to 14 hours. Some components of toothpastes, including sodium lauryl sulfate and calcium, interact with chlorhexidine to reduce its effectiveness; therefore, its use should be delayed for 30 minutes after toothbrushing.56,57

Use of antibiotics and antiseptics

Eva M. Sarkiala-Kessel, in Oral and Maxillofacial Surgery in Dogs and Cats, 2012

The cationic nature of chlorhexidine allows it to bind to negatively charged surfaces in the mouth, such as tooth and mucosa.78–80 It is then released over time and provides a continuing bacteriostatic effect.79 Chlorhexidine does not absorb through the oral tissues.80

Bactericidal and Virucidal Activity of Povidone-Iodine and Chlorhexidine Gluconate Cleansers in an In Vivo Hand Hygiene Clinical Simulation Study

Infect Dis Ther. 2018 Jun; 7(2): 235–247.

Povidone-iodine cleanser and chlorhexidine gluconate cleanser were both more effective than plain soap at removing bacteria from volunteers’ hands. Povidone-iodine cleanser was more effective than plain soap at removing viruses, except when using 3 mL product for 15 s. Chlorhexidine gluconate cleanser was less effective than plain soap at removing viruses in all tests. The adapted test method using murine norovirus (MNV) worked well, giving consistent results for each product, and may be suitable for future testing of antiseptic products against viruses.

The bicationic character of the CHG molecule, that is responsible for adhesion to surfaces and retention of other components as observed in oral use [4041], may retain viruses too. This retention phenomenon is not only seen with viruses [42] but also with some Gram-negative bacteria such as A. baumannii [31]. It should be noted that, due to the established cumulative effect of CHG [23], repeated use may result in greater activity than shown in single-use studies, although repeated use of CHG may also increase its known risk of development of resistance [22943]. In contrast, PVP-I demonstrates less persistent activity [23], but is not associated with development of resistance [44].

We have shown for the first time in this study that the bacterial testing from EN1499 can be adapted to MNV-based (murine norovirus) viral testing and may be a good basis for further virucidal CEN standards, pending further validation as interlaboratory tests. It may be hypothesized that antiseptic products which are effective against non-enveloped viruses such as MNV will be effective against enveloped viruses such as Ebola (EBOV), severe acute respiratory syndrome and Middle East respiratory syndrome coronaviruses (SARS- and MERS-CoV), influenza and other emerging viruses; this is supported by the results of in vitro suspension tests with the modified vaccinia virus Ankara [12, 13]. CHX appears to be more virucidal against envelope viruses like COVID-19 than non-enveloped viruses like MNV.

Coronavirus disease 2019 (COVID-19) – UpToDate › coronavirus-disease-2019-covid-19 › abstract

… Abstracts for References 57,58 of ‘Coronavirus disease 2019 (COVID-19)’ … benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective.

2020 Feb 24

J Hosp Infect. 2020 Mar;104(3):246-251. doi: 10.1016/j.jhin.2020.01.022. Epub 2020 Feb 6.

Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.

Kampf G1, Todt D2, Pfaender S2, Steinmann E2.

Author information


Currently, the emergence of a novel human coronavirus, SARS-CoV-2, has become a global health concern causing severe respiratory tract infections in humans. Human-to-human transmissions have been described with incubation times between 2-10 days, facilitating its spread via droplets, contaminated hands or surfaces. We therefore reviewed the literature on all available information about the persistence of human and veterinary coronaviruses on inanimate surfaces as well as inactivation strategies with biocidal agents used for chemical disinfection, e.g. in healthcare facilities. The analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days, but can be efficiently inactivated by surface disinfection procedures with 62-71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Other biocidal agents such as 0.05-0.2% benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective. As no specific therapies are available for SARS-CoV-2, early containment and prevention of further spread will be crucial to stop the ongoing outbreak and to control this novel infectious thread.

Here’s what Chinese doctors learned about prevention and detection of COVID-19

MARCH 15, 2020

Viruses generally can survive for several hours on smooth surfaces. If the temperature and humidity permit, they can survive for several days. The novel coronavirus is sensitive to ultraviolet rays and heat. Sustained heat at 132.8° F for 30 minutes, 75% alcohol, chlorine-containing disinfectants, peracetic acid, chloroform, and other lipid solvents can effectively inactivate the virus. Chlorhexidine (also known as chlorhexidine gluconate) also efectively inactivates the virus.

Kaiser Permanente

chlorhexidine gluconate 0.12 % mouthwash

Other uses

This drug may also be used by people with weakened immune systems to decrease mouth sores (mucositis). It may also be used to help hospitalized patients breathing through a ventilator not get pneumonia.

Questionable Benefit of Oral Chlorhexidine in Mechanically Ventilated Patients

The Hospitalist. 2014 August;2014(8)

Author(s): Nita Shrikant Kulkarni, MD

Oral care with chlorhexidine decreases the incidence of respiratory tract infections in mechanically ventilated cardiac surgery patients, but not in noncardiac surgery patients. Additionally, the use of chlorhexidine does not have a statistically significant effect on mortality, length of stay (LOS), or duration of mechanical ventilation in either population. Further research is needed to determine the benefit and safety of this common intervention in different patient populations.

A survey of research on the inactivation of other coronaviruses using various biocidal agents suggests that disinfecting surfaces contaminated with SARS-CoV-2 may also be achieved using similar solutions (within one minute of exposure on a stainless steel surface), including 62–71% ethanol, 50–100% isopropanol, 0.1% sodium hypochlorite, 0.5% hydrogen peroxide, and 0.2–7.5% povidone-iodinebenzalkonium chloride and chlorhexidine gluconate are less effective.[242] % concentration is not mentioned!

Chlorhexidine (CHG) Bathing to Prevent Healthcare-Linked Infections

Daily CHG bathing generally lowers your risk of getting an infection in the hospital. You are less likely to get sick from a germ that is very hard to treat. One example is methicillin-resistant Staphylococcus aureus (MRSA). CHG bathing can also help prevent other types of infections such as:

Vancomycin-resistant Enterococcus (VRE)

Infections from central venous catheters

Infections at surgical sites

Infections from ventilator use

Role of chlorhexidine gluconate in ventilator-associated pneumonia prevention strategies in ICU patients: where are we headed?

Tanmay S PanchabhaiNeha S Dangayach

Critical Care

volume 13, Article number: 427 (2009) Cite this article

We read with interest the recent study by Scannapieco and colleagues [1], which concluded that twice-daily oral rinse with 12% chlorhexidine failed to reduce the number of potential respiratory pathogens in dental plaque, mortality, the incidence of ventilator-associated pneumonia (VAP), the length of intensive care unit (ICU) stay and the duration of mechanical ventilation in trauma ICU patients.

Trauma ICU patients are similar to mixed ICU patients with respect to risk factors for developing VAP, unlike patients undergoing elective cardiac surgery. Use of 0.12% chlorhexidine decreases the incidence of VAP in patients undergoing elective cardiac surgery. In mixed ICU patients, chlorhexidine at concentrations less than 0.2% has consistently been shown to have no benefit [2]. A randomized trial using 2% chlorhexidine has, however, demonstrated a reduction in VAP rates in these patients [3]. A previous study showed that 12-hourly application of chlorhexidine has a sustained preventive effect on biofilm formation [4]. The lack of benefit from twice-daily oral cleansing with chlorhexidine in the present study may be due to the lower concentration of chlorhexidine.

The authors’ recommendation for investigation into mechanical plaque removal with chlorhexidine would conceptually have some added benefit. Mechanical plaque removal with chlorhexidine, however, has not affected outcomes in ICU patients in two studies [56].

We therefore suggest that further studies using oral chlorhexidine in ICU patients should be conducted using higher concentrations (2%) to test the most appropriate frequency of use, since oral cleansing is a nursing-driven intervention and clinical trials with chlorhexidine are yet to demonstrate a mortality benefit.

Respiratory Care Journal

Effect of Oral Hygiene and 0.12% Chlorhexidine Gluconate Oral Rinse in Preventing Ventilator-Associated Pneumonia After Cardiovascular Surgery

Liliana Noemí Nicolosi, Maria del Carmen Rubio, Carlos Daniel Martinez, Nidia Noemí González and Marisa Edith Cruz

Respiratory Care April 2014, 59 (4) 504-509; DOI:


BACKGROUND: Ventilator-associated pneumonia (VAP) is a nosocomial infection of multifactorial etiology and has a negative influence on cardiovascular surgery (CVS) outcomes.

OBJECTIVES: Determine the effect of toothbrushing plus 0.12% chlorhexidine gluconate oral rinse in preventing VAP after CVS.

METHODS: In a quasi-experimental study, patients undergoing heart surgery were enrolled in a protocol for controlling dental biofilm by proper oral hygiene (toothbrushing) and oral rinses with 0.12% chlorhexidine gluconate (Group 1), and they were compared with a historical control group (Group 2), which included patients who underwent cardiac surgery between 2009 and 2010 and who received regular oral hygiene care. Seventy-two hours before surgery, a dentist provided instruction and supervised oral hygiene with toothbrushing and chlorhexidine oral rinses to patients in Group 1.

RESULTS: Each group comprised 150 patients. A lower incidence of VAP (2.7% [95% CI 0.7–7.8] vs 8.7% [95% CI 4.9–14.7], P = .04) and a shorter hospital stay (9 ± 3 d [95% CI 8.5–9.5] vs 10 ± 4 d [95% CI 9.4–10.7], P = .01) were observed in Group 1. No significant differences in all-cause in-hospital death were observed between groups (5.3% vs 4.7%, P > .99). The risk for developing pneumonia after surgery was 3-fold higher in Group 2 (3.9, 95% CI 1.1–14.2).

CONCLUSIONS: Oral hygiene and mouth rinses with chlorhexidine under supervision of a dentist proved effective in reducing the incidence of VAP.

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This post was written by Dr. Jeffrey Dorfman