Chlorhexidine mouthwash reduces the salivary viral load of SARS-CoV-2: a randomized clinical trial

Objectives This study aimed to evaluate the effect of 0.12% chlorhexidine gluconate on the salivary load of SARS-CoV-2. Materials and methods A randomized, double-blind, placebo-controlled trial was performed on 100 participants positive for SARS-CoV-2. In the test group (n=50), volunteers gargled with a mouthwash containing 15 mL of 0.12% chlorhexidine gluconate for one minute, while the control group (n = 50) used a placebo. Saliva samples were obtained before (baseline) and 5 and 60 minutes after using the solutions. Real-time reverse transcription polymerase chain reaction assays (qRT-PCR) were carried out and the cycle threshold (Ct) was computed. The chi-square test and t-test were used for group comparison (p≤0.05). Results The differences in Ct values between the 5-minute evaluation and baseline (test group: 2.19±4.30; control: -0.40±3.87, p=0.002) and between 60 minutes and baseline (test group: 2.45±3.88; control: 0.76±4.41, p=0.05) were significantly greater in the test group, revealing a reduction of viral load. Furthermore, there was a reduction in the load of SARS-CoV-2 in 72% of the volunteers using chlorhexidine versus 30% in the control group (p=0.001). Conclusions Chlorhexidine gluconate (0.12%) was effective in reducing salivary SARS-CoV-2 load for at least 60 minutes.