All About NAC (N acetylcysteine): What it is and what benefits it has Zenement Supplementation with a combination of glycine and N acetylcysteine (precursors to glutathione) improved glutathione levels, oxidative stress, mitochondrial function, muscle strength, exercise capacity, cognition in older individuals. The supplement NAC Skin Care Benefits of NAC NAC (N acetyl cysteine) is a powerful compound that plays an important role in supporting the body's natural detoxification and antioxidant systems. One of its key functions is helping the body produce glutathione, NAC is one of those supplements that I always have on hand. It's impressive how broadly supportive NAC is. One time I was taking NAC 500 mg every day for about two NAC vs. Glutathione: Breaking Down the Benefits for Detox, Immunity, and More