N-Acetyl-Cysteine is a form of the amino acid cysteine. The body uses its sulfur to make glutathione, a central antioxidant that supports detoxification and immune function.
NAC helps thin mucus in the airways. It also aids the liver's natural detox pathways and bolsters antioxidant defenses. Some evidence points to support for mood balance and cognitive function.
People take NAC as a capsule or powder, often splitting doses across the day. Food helps reduce stomach upset. Nausea, vomiting, and digestive discomfort can happen. NAC may interact with blood thinners. Those with asthma or bleeding disorders should use caution.