Can N-Acetylcysteine prevent colds?

Yes, N-Acetylcysteine (NAC) may help in preventing colds and reducing the severity of symptoms. In a study referenced by Andrew Huberman, it was found that a significant reduction in the number of symptomatic influenza cases occurred among those taking NAC compared to those who did not. Specifically, only 25% of people taking NAC contracted influenza, compared to 79% in the placebo group, suggesting a strong preventive effect against cold and flu-like symptoms due to the increase of glutathione levels caused by NAC 1.

Andrew Huberman also mentioned the personal use of NAC, not only as a preventive measure but also as a treatment once symptoms developed, and noted its efficacy in reducing mucus and congestion 1. He suggests a dosage of about 1200 milligrams per day, split into two doses, and emphasizes that while more randomized control trials would be beneficial for solid confirmation, the existing data and anecdotal evidence point towards NAC's potential benefits in this context 1.