I have been taking NAC (n-acetylcysteine) as a supplement for a while. You can (still) buy it on Amazon. From an Elsevier press release “The authors draw attention to several randomized clinical studies in humans that have found that over the counter supplements such as n-acetylcysteine (NAC), which is used to treat acetaminophen poisoning and is also used as a mucus thinner to help reduce bronchitis exacerbations, and elderberry extracts, have evidence for shortening the duration of influenza by about two to four days and reducing the severity of the infection”. Anecdotally, I stopped taking NAC for a few months and happened to catch a cold. The phlegm took longer to go away than normal and I happened to read that NAC, which I still had, helped with phlegm, so I started taking NAC again and my phlegm problem quickly went away, at a faster rate than it had been.
I have been taking NAC (n-acetylcysteine) as a supplement for a while. You can (still) buy it on Amazon. From an Elsevier press release “The authors draw attention to several randomized clinical studies in humans that have found that over the counter supplements such as n-acetylcysteine (NAC), which is used to treat acetaminophen poisoning and is also used as a mucus thinner to help reduce bronchitis exacerbations, and elderberry extracts, have evidence for shortening the duration of influenza by about two to four days and reducing the severity of the infection”. Anecdotally, I stopped taking NAC for a few months and happened to catch a cold. The phlegm took longer to go away than normal and I happened to read that NAC, which I still had, helped with phlegm, so I started taking NAC again and my phlegm problem quickly went away, at a faster rate than it had been.