Salt fights viruses by working inside your cells while the virus is copying itself, not by directly killing the virus or stopping it from entering cells.

Salt's ability to fight viruses depends on how chloride moves inside cells, not sodium. When chloride movement is blocked, salt can't stop viruses, but blocking sodium movement doesn't change salt's virus-fighting power.

Salt might help fight viruses like coronaviruses in lab tests, and this could be why people feel better when they use salt-based treatments.

Adding more salt to the liquid that cells grow in makes it harder for many viruses to copy themselves inside those cells, and the more salt you add, the less the viruses copy themselves, without harming the cells.

Salty water might help your body's cells fight off viruses better by boosting natural defenses, which could explain why saline treatments work in some medical trials, but more research is needed to be sure.