N-Acetylcysteine: Over-The-Counter Supplement for Mental Health and viral Infections?

Could an over the counter supplement help us fight viruses and depression?

I regularly discuss the over-the-counter supplement N-acetylcysteine (NAC) with my psychiatric patients, mostly because of its potential benefits for depression, psychosis, and cognition. But it also may help fight viral infections. 

A 1997 Italian study gave NAC to about 250 people and tracked their flu symptoms over 6 months. The results were nothing short of remarkable. 
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Among those who were infected with influenza, 79% taking placebo experienced symptoms, versus only 25% of those taking NAC (Figure 1). That is a huge difference. If these results hold up, it could fundamentally change how we experience flu season. 

Now for the head-scratcher: This study is over 20 years old. Why hasn’t this been tested again? If it holds up, it should be aggressively pursued as a safe, inexpensive treatment for this serious disease, and tested for other viruses. And if not, we need to know so we can move on to other things. 

(hint hint hint hint if any research funders are reading this) 

Other studies done since (like this 2010 study) have shown that NAC probably does inhibit certain types of influenza virus and may help prevent lung damage during infection (like in this study). It also may help with chronic lung disease, and may inhibit other types of viruses, possibly even in the coronavirus family. 

And I previously mentioned how NAC may help with cognition. New research suggests that the flu may cause us cognition problems that last for months, long after we think we recovered from it. What if NAC helps prevent this impairment? That research needs to be done, and soon. 


THE TAKE HOME: 
What does this mean for you personally? It may be worth talking to your doctor more about NAC, especially if you have mental health concerns that might benefit from it.