N-acetylcysteine (NAC) thins mucus as a mucolytic because of its its free sulfhydryl group which reduces disulfide bonds in mucus glycoproteins. Additionally, it is a strong antioxidant. NAC may be beneficial in treating or preventing SARS-CoV-2 infections in the following ways:

• NAC may be able to cleave SARS-CoV-2 E protein which would decrease its infectivity
• NAC has been shown to decrease angiotensin II bonds to angiotensin II type 1 receptors in vitro
• NAC has been shown to block ACE activity and limit the amount of Ang II both in vitro and clinically
• NAC may be able to counteract the reactive oxygen species (ROS) produced by cytokine storm syndrome
• NAC has been shown to restore platelet GSH reserves and prevent protein glycosylation, a pathological mechanism of COVID-19 in diabetic patients
• NAC has been shown to inhibit NF-κB activation in an in vitro influenza (A and B) model which mediates COVID-19 pathology in the lungs by initiating the production of pro-inflammatory cytokines