Forever Young Radio Show


By Dr. Mark Stengler, NMD, MS.

I have been recommending N-acetyl-cysteine (NAC) for decades to my patients as a non-prescription supplement. NAC (sometimes called acetyl-cysteine) is a potent antioxidant in the body as it neutralizes harmful free radicals that damage cells. It also increases the body’s glutathione levels, which is possibly the most powerful antioxidant in the body. NAC is used to support liver and kidney detoxification and to support immunity.

Hospitals Use NAC

NAC has specific uses in the hospital setting. NAC is given to patients who have overdosed on acetaminophen to prevent liver toxicity. In addition, it is used orally and by nebulization to reduce mucus thickness and promote drainage in the respiratory system.

Holistic Medicine and NAC

I discuss several reasons why I recommend NAC to patients below.

Bronchitis and Sinusitis

NAC has the unique property of breaking up mucus and thus thinning the mucus to drain better. NAC also has an anti-inflammatory effect on the airway. I often recommend it when patients have bronchitis, pneumonia, chronic obstructive pulmonary disease (COPD), sinusitis, or any condition where mucus is problematic in the respiratory system. In a review of several studies, the supplementation of NAC at doses between 600 to 1,200 mg per day in over 4000 people with chronic bronchitis or COPD resulted in a significant reduction of these conditions. NAC has also been shown to be effective when used as an inhalation treatment (nebulized). I often prescribe breathing treatments to patients in both oral and nebulized forms at our clinic. Please note that nebulized NAC must be prescribed by a doctor from a pharmacy.

Immune Support

Research has shown that NAC improves immune function, including markers such as natural killer cells. Additionally, a study found that only 25 percent of older people injected with the flu virus experienced flu symptoms after taking NAC six months, versus 79 percent who took a placebo.

Liver Support

NAC supports healthy liver function due to its anti-inflammatory, antioxidant, and glutathione enhancing effects. Research shows that it reduces fat accumulation in the liver and liver enzyme levels in certain studies.

Kidney Protection

NAC is one of the few agents shown to protect against kidney injury from contract dyes used in imaging. The protective effects are thought to be due to NAC’s antioxidant and vasodilating actions. In addition, research shows that NAC prevents kidney cell death (apoptosis). Studies have been mixed on the benefit of NAC preventing kidney injury from contrast dye. However, a study published in the Journal of the American Heart Association reported that NAC supplementation was shown to be associated with a significant decrease in kidney injury from contrast dye. The dosages used in this meta-analysis varied greatly.

Mood Balancing

A review of studies examining the evidence for NAC in psychiatry and neurology was published in Neuroscience & Biobehavioral Reviews. The researchers summarized their findings: “…we find favorable evidence for the use of NAC in several psychiatric and neurological disorders, particularly autism, Alzheimer’s disease, cocaine and cannabis addiction, bipolar disorder, depression, trichotillomania[hair pulling], nail biting, skin pricking, obsessive-compulsive disorder, schizophrenia, drug induced neuropathy, and progressive myoclonic epilepsy…..Overall, NAC treatment appears to be safe and tolerable.”

NAC has a balancing effect on the excitatory neurotransmitter known as glutamate. In addition, it has a regulatory impact on the neurotransmitter dopamine, which can cause depression and motivation problems when low


I generally recommend 1200mg of NAC twice daily on an empty stomach. People on psychiatric medications should check with their doctor first before using.


Deepmala et al. Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review. Neurosci Biobehav Rev. 2015 Aug;55:294-321.

De Flora S, Grassi C, Carati L, “Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment,” Eur Respir J. 1997 Jul;10(7):1535-41.

Xu R, Tao A, Bai Y, Deng Y, Chen G. Effectiveness of N ‐Acetylcysteine for the Prevention of Contrast‐Induced Nephropathy: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials. J Am Heart Assoc. 2016;5(9). doi:10.1161/jaha.116.003968

Dr. Mark Stengler NMD, MS, is a bestselling author in private practice in Encinitas, California, at the Stengler Center for Integrative Medicine. His newsletter, Dr. Stengler’s Health Breakthroughs, is available at His clinic website is

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