My husband takes 2 NAC 600 daily. I’ve been taking it for years to enhance my memory and when I read that it is also good for copd I had him start it immediately. He has had no issues with congestion.

My doctor wants me to take two capsules a day for my immune system.

Sorry I cannot help you have not heard of that. You can always google it. Wish you the best in getting informed on it. Breathe easy!

NAC is usually taken because it helps get mucous up and out. If you look at the publication sites even on a google search, you'll note that most sites talk about the effect of NAC on mucous production and how that improves lung health. There are very few that actually take the NAC to help the immune system idea very far, so I think that's incidental.

what exactly is NAC and where do you get it?