One of NAC's most important therapeutic uses is in treating respiratory conditions. It has been found to be effective in reducing symptoms and improving lung function in conditions such as chronic obstructive pulmonary disease (COPD), asthma, and bronchitis. NAC works by breaking down mucus in the respiratory system, making it easier to clear out, and also by reducing inflammation in the airways.
NAC is a member of the mucolytic drug class. One action of NAC is to break up the sulfide bonds in mucus so as to facilitate their easier expulsion from the respiratory tract. This treatment can dilute the viscosity of phlegm and sputum, soften them and allow looser coughing.