N-Acetylcysteine (NAC) is a modified form of the amino acid cysteine. NAC is commonly used as a supplement due to its ability to increase the production of glutathione (GSH), a powerful antioxidant that helps protect cells from damage caused by harmful molecules called free radicals. GSH plays a critical role in the body's defense against oxidative stress, which is known to contribute to a wide range of diseases and health problems, including cancer, heart disease, and neurodegenerative disorders. NAC is considered a precursor to GSH because it helps increase the body's production of this important antioxidant. Several studies have shown that NAC supplementation can improve antioxidant status and reduce the risk of oxidative stress-related disorders. For example, NAC has been found to improve lung function in people with chronic obstructive pulmonary disease (COPD) and reduce the incidence of acute respiratory distress syndrome (ARDS) in critically ill patients. NAC has also been studied for its potential benefits in treating psychiatric disorders, such as obsessive-compulsive disorder (OCD), addiction, and depression. One study found that NAC supplementation reduced symptoms of OCD by 47% in just 12 weeks. Other studies have found that NAC may help reduce cravings for drugs and alcohol and improve mood in people with depression. In addition to its role in promoting GSH production and antioxidant activity, NAC has been found to have other health benefits as well. For example, it may help improve insulin sensitivity and lower blood sugar levels in people with type 2 diabetes. NAC has also been studied for its potential to improve liver function and reduce the risk of liver damage caused by alcohol consumption or medications. Overall, NAC is a promising supplement for promoting overall health and reducing the risk of a wide range of diseases and health problems. However, it is important to note that NAC should not be used as a substitute for a healthy diet and lifestyle. Consult with a healthcare professional before taking NAC or any other supplement, and be sure to follow dosage instructions carefully.