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

  • days left to enroll
  • participants needed
  • sponsor
    University of California, San Francisco
Updated on 6 June 2022
antiviral drugs


In this pilot trial, 150 confirmed COVID-19 individuals will be randomly assigned to 1 of 5 groups: distilled water, CloSYS Ultra Sensitive Rinse (Rowpar Pharmaceutical Inc., USA), Oral-B Mouth Sore (Oral-B, USA), Crest Pro-Health Multi-Protection (Crest, USA), or Listerine Zero (Johnson and Johnson, USA).

Study participants will be asked to rinse/gargle with 10-20ml (according to the rinse instructions) of the assigned solutions 4 times per day, for 30-60 seconds, for 4 weeks.


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 dental unit waterlines, and biofilm control in ultrasonic dental scaling units. A recent study has shown that CloSYS Ultra Sensitive Oral Rinse reduced the viral load of SARS CoV 2, SARS CoV, and Influenza A H3N2 to a varying extent. The data show that the viral load reduction of SARS CoV 2 by Ultra Sensitive rinse was 10 fold more than the reduction of SARS CoV in 30s. 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 four 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 it to the others for a 2 to 4 week period. An interim analysis is planned when 10 participants per arm (50 total) complete the study using the alpha-spending function with O'Brien-Fleming boundary rule.

Condition COVID-19, SARS-CoV 2, Severe Acute Respiratory Syndrome Coronavirus 2, Virus Disease, Coronavirus Infections, Pharyngeal Diseases
Treatment Distilled water, Oral-B Mouth Sore mouthwash, Crest Pro-Health Multi-Protection mouthwash, CloSYS Ultra Sensitive Rinse mouthwash, Listerine Zero Mouthwash Product
Clinical Study IdentifierNCT04409873
SponsorUniversity of California, San Francisco
Last Modified on6 June 2022


Yes No Not Sure

Inclusion Criteria

Tested positive for COVID-19 with a sample collected in the prior 7 days
Ability to read and speak English or Spanish
Ability to participate in the study for 4 weeks
Being asymptomatic or having mild or moderate symptoms (for example, sore throat, coughing, fever, fatigue)
Ability to rinse/gargle
Not having any condition that might worsen with gargling solutions
Not having a history of mouthwash sensitivity
Not having an allergy to any mouthwash that has been used before
Not using another mouthwash/gargling solution since the most recent positive test
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, and can videoconference (like zoom) on a cellphone, tablet, or computer for sample collection instructions

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
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact



Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note