Antiseptic Mouthwash / Pre-Procedural Rinse on SARS-CoV-2 Load (COVID-19)


In this pilot trial, 120 confirmed COVID-19 individuals will be randomly assigned to 1 of 4 groups: distilled water, CloSYS (Rowpar Pharmaceutical Inc., USA), Oral-B Mouth Sore (Oral-B, USA), or Crest Pro-Health Multi-Protection (Crest, USA).

Study participants will be asked to rinse/gargle with 10ml (2 teaspoons) of the assigned solutions 4 times per day, for 15 seconds, for 4 weeks.

Full Title of Study: “Effect of Antiseptic Mouthwash/Gargling Solutions and Pre-procedural Rinse on SARS-CoV-2 Load (COVID-19)”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Supportive Care
    • Masking: Double (Participant, Outcomes Assessor)
  • Study Primary Completion Date: October 31, 2020

Detailed Description

SARS-CoV-2, the virus causing COVID-19, has affected vulnerable individuals, especially those with comorbidities, and high exposure health care workers (HCWs). Typically, the virus first colonizes in the upper respiratory tract (URT) causing clinical symptoms such as coughing, sore throat, and then is transferred to the lower respiratory tract (LRT) which can lead to severe pneumonia, acute respiratory distress syndrome (ARDS), sepsis, and death, if it is not managed.

The World Health Organization (WHO) has presented comprehensive guidelines underscoring personal hygiene measures including respiratory hygiene against SARS, MERS, influenza, and now SARS-CoV-2 / COVID-19. While personal protection equipment (PPE), personal hygiene measures, environmental infection control, and physical distancing are crucial in mitigating disease transmission, respiratory hygiene measures do not prevent SARS-CoV-2 colonization in URTs and LRTs of infected individuals (symptomatic and asymptomatic).

Experimental and clinical research studies on infections similar to COVID-19 such as SARS, MERS, and H5N1 have shown that using antiseptic mouthwash/gargling solutions, such as products containing chlorhexidine gluconate (CHG), polyvinylpyrrolidone iodine (PVP-I), chlorine dioxide (ClO2), cetylpyridinium chloride (CPC), and hydrogen peroxide (H2O2) can reduce viral load. A randomized controlled trial (N=387) showed efficacy and cost-effectiveness of gargling with water or a product containing PVP-I (3X/day, 20 seconds) on URTIs in healthy volunteers (18-65 years) over 60 days from a societal perspective; in vitro studies have shown that CloSYS, an over the counter mouthwash containing ClO2, was effective on inactivating SARS-CoV as well as disinfecting infected surfaces, dental unit waterlines, and biofilms in ultrasonic dental scaling units. Recently, the US Centers for Disease Control (CDC) and the American Dental Association (ADA) have recommended using a mouthwash containing 1.0-1.5% H2O2 as a pre-procedural rinse before dental treatment to potentially reduce SARS-CoV-2 load; however, no in vivo clinical studies have been conducted to support this claim.

The aim of this pilot trial is to evaluate the effect of three over the counter antiseptic mouthwash/gargling solutions compared to a control (distilled water) to reduce SARS-CoV-2 load. In addition, study participants will be assessed for the severity of their clinical symptoms during the study period. The 4-week protocol was selected as studies have shown that patients can continue to shed the virus and potentially transmit to the others for a 2 to 4 week period.


  • Drug: Oral-B Mouth Sore mouthwash
    • Rinse and gargle 4 times daily, for 15 seconds, for 4 weeks.
  • Drug: Crest Pro-Health Multi-Protection mouthwash
    • Rinse and gargle 4 times daily, for 15 seconds, for 4 weeks.
  • Drug: CloSYS mouthwash
    • Rinse and gargle 4 times daily, for 15 seconds, for 4 weeks.
  • Drug: Distilled water
    • Rinse and gargle 4 times daily, for 15 seconds, for 4 weeks.

Arms, Groups and Cohorts

  • Placebo Comparator: Control (Distilled Water)
    • Over the counter: Distilled water
  • Experimental: Oral-B Mouth Sore (H2O2) mouthwash
    • Over the counter: Oral-B Mouth Sore (Oral-B, USA) contains hydrogen peroxide (H2O2)
  • Experimental: Crest Pro-Health Multi-Protection (C21H38ClN) mouthwash
    • Over the counter: Crest Pro-Health Multi-Protection (Crest, USA) contains cetylpyridinium chloride (C21H38ClN)
  • Experimental: CloSYS (ClO2) mouthwash
    • Over the counter: CloSYS (Rowpar Pharmaceutical Inc., USA) contains stabilized chlorine dioxide (ClO2)

Clinical Trial Outcome Measures

Primary Measures

  • Change in SARS-Cov-2 viral load
    • Time Frame: Baseline to 4 weeks
    • Change in saliva wash RT-PCR SARS-Cov-2 viral load

Secondary Measures

  • Change in self-reported clinical symptom onset
    • Time Frame: Baseline to 4 weeks
    • Change in self-reported (questionnaire) clinical symptom onset. A symptom checklist will include: cough, runny nose, scratchy/sore throat, fever, chills, fatigue, muscle ache, shortness of breath, diarrhea/nausea/vomiting, loss of taste/smell, and red /painful eye.
  • Change in healthcare utilization and hospitalization
    • Time Frame: Baseline to 4 weeks
    • Change in healthcare utilization and hospitalization

Participating in This Clinical Trial

Inclusion Criteria

  • Ability to gargle
  • Not having any condition that might worsen with gargling solutions
  • Not having an allergy to a study mouthwash ingredient
  • Not using another mouthwash/gargling solution
  • Not taking antimicrobial medications (antibacterial, antiviral, antibiotics including off-label FDA-approved medications such as hydroxychloroquine)
  • Anticipated ability to participate in the study for 4 weeks
  • Have a cellphone and agree to receive text messages for reminders to use mouthwash during the day and for follow-up visits

Exclusion Criteria

  • People who because of their symptoms intend to receive antiviral medications that could potentially affect viral load in their saliva samples
  • Pregnant or lactating women due to potential aversions to mouthwash solution taste/smell.

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • University of California, San Francisco
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Stuart A Gansky, DrPH, Principal Investigator, Professor and Lee Hysan Chair of Oral Epidemiology
  • Overall Contact(s)
    • Stuart A Gansky, DrPH, 415-502-8094,


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