Existing and potential therapeutic uses for N-acetylcysteine: the need for conversion to intracellular glutathione for antioxidant benefits

This 2017 review examined earlier human, animal, and laboratory studies rather than testing a new group of people. N-acetylcysteine, or NAC, is a medicine and supplement that can be converted into glutathione, a natural antioxidant that helps protect cells. The review found that NAC can help in specific medical situations, such as some poisonings, but evidence that it reliably raises cell glutathione or prevents age-related disease was limited and uneven. Results may depend on the dose, the person, and how well NAC enters cells.

What this means for you: This review does not show that NAC is a proven longevity supplement. It has established medical uses, but routine use for general antioxidant protection should not be based on this evidence alone.