N-Acetyl Cysteine is an anti-oxidant that is helpful for the nutritional support of lung functioning. As with other nutrients that support lung function, one important function is that of reducing inflammation.

NAC has an added benefit that it also helps thin the mucus in the airway, making it easier for horses to cough and expel particles in the lungs. This is particularly helpful in horses that are in dusty environments, horses exposed to dust in their hay or in their barn, or horses exposed to the smoke from wild-fires.