N-acetylcysteine (NAC), a sulfur-containing amino acid, is the precursor to the amino acid L-cysteine, one of the three amino acids that comprise glutathione. Animal and human studies of NAC have concluded it has potent antioxidant activity.* In addition to its antioxidant activity, NAC is effective in promoting normal liver detoxification and protecting the liver and the kidneys from toxic insults.* As a sulfur source, NAC stimulates the synthesis and activity of glutathione, an important antioxidant in its own right.* Research suggests NAC is capable of enhancing immune function.* NAC also helps maintain good pulmonary health due to its mucolytic activity.*

In a double-blind, placebo-controlled trial, NAC positively impacted lymphocyte cell numbers, white cells that are crucial to normal immune function.*

The sulfur in NAC is able to cleave the bonds in mucoproteins, which results in mucus being broken into smaller, less viscous pieces.* Hence, NAC's ability to decrease the viscoelasticity of nasal mucus and increase the clearance of mucus by the cilia by thinning secretions helps maintain good pulmonary health.*