NAC not only has significant anti-aging benefits but plays an often overlooked role in treating all kinds of addictions. Even if you are taking the life extension mix, the addition of NAC may prove beneficial.  NAC can heal lung tissue damage and, in specific cases, possibly treat COPD.  It has many other uses. The following link provides further details. https://www.lifeextension.com/Magazine/2010/5/N-Acetyl-Cysteine/Page-01