Summary of COVID-19 cetylpyridinium chloride studies
1. Rengifo et al., A Mouthwash with Cetylpyridinium Chloride is reducing salivary SARS-CoV-2 viral load in +COVID-19
23 patient cetylpyridinium chloride late treatment RCT: 83% improved viral clearance (p=0.06).RCT 23 patients in Colombia, showing improved viral clearance with cetylpyridinium chloride plus chlorhexidine mouthwash.
May 2023, Revista Estomatologia, https://estomatologia.univalle.edu.co/index.php/revista_estomatologia/article/download/12669/15872, https://c19p.org/rengifo
2. Ponphaiboon et al., Efficacy of Nasal Spray, Mouth Spray, and Mouthwash Containing Limonene, Cetylpyridinium Chloride, and Monolaurin in COVID-19 Management: A Double-Blind, Randomized, Placebo-Controlled Trial
116 patient cetylpyridinium chloride early treatment RCT: 36% improved recovery (p=0.006).RCT 120 low-risk COVID-19 patients showing improved recovery with nasal and oral formulations containing cetylpyridinium chloride, D-limonene, and monolaurin (the nasal formulation contained D-limonene and cetylpyridinium chloride, while the oral formulation contained D-limonene, monolaurin, and cetylpyridinium chloride). No patients progressed to severe disease. No adverse events were reported in either group during the 7 day treatment period or 1 month followup. Placebo contents are not specified - authors note only "a homogenized liquid carrier", however any liquid rinse may have some efficacy via mechanical clearance.
Sep 2025, MDPI AG, https://www.preprints.org/manuscript/202509.1594/v1, https://c19p.org/ponphaiboon2
3. Bonn et al., Efficacy of a Mouthwash Containing CHX and CPC in SARS-CoV-2–Positive Patients: A Randomized Controlled Clinical Trial
61 patient cetylpyridinium chloride early treatment RCT: 85% improved viral clearance (p=0.2).RCT 61 COVID+ patients showing improved reduction in viral infectivity with a mouthwash containing 0.05% cetylpyridinium chloride (CPC) and 0.05% chlorhexidine digluconate (CHX), compared to 0.9% NaCl. The study only analyzes short-term changes in viral load 30 minutes after treatment.
Mar 2023, J. Dental Research, https://journals.sagepub.com/doi/10.1177/00220345231156415, https://c19p.org/bonncpc
4. Gansky et al., Antiseptic Mouthwash / Pre-Procedural Rinse on SARS-CoV-2 Load (COVID-19) (AMPoL)
54 patient cetylpyridinium chloride early treatment RCT: 60% improved recovery (p=1).Early terminated RCT with very limited information reported in the registry and only one patient showing symptoms. There is not enough information to assess the viral load results in the registry - the protocol indicates right-censoring for patients with undetectable viral load which may be the majority of patients at 4 weeks.
Nov 2023, NCT04409873, https://clinicaltrials.gov/study/NCT04409873, https://c19p.org/ganskycpc