NAC supplements have been used to improve COPD symptoms, exacerbations and lung decline ( 17 , 18 , 19). In a one-year study, 600 mg of NAC twice a day significantly improved lung function and symptoms in those with stable COPD ( 20 ). Those with chronic bronchitis can also benefit from NAC.

Is NAC safe to take daily?

There is no recommended daily allowance for NAC, because unlike vitamins, it's not an essential nutrient. The dosage used to prevent radio contrast dye damage is 600 mg to 1200 mg every 12 hours for 48 hours.

Does NAC really work?

There's evidence it can help prevent kidney or neurologic damage caused by some drugs. NAC might help prevent colon cancer in people with some types of colon polyps, but more research is needed to be sure. NAC does not seem to reduce the risk of lung cancer or head and neck cancer.