Question: I am interested in trying Swanson Ultra Dr. Stephen Langer's Glutathione Precursor Complex, but I have read that zinc should be taken in conjunction with N-Acetyl-L-Cysteine (NAC), and I see that the formula does not contain zinc.
Zinc isn’t really required for NAC to work properly, but they do help in similar aspects so they might be recommended together. It would be similar to how it could be recommended to add bananas to strawberries because the flavors compliment each other, but it’s not required for strawberries to taste good. If you wanted to add Zinc to this formula (either separately or in a multiple vitamin complex), that would be perfectly fine.
As far as Zinc products, they are all Zinc, but they differ in which nutrient Zinc gets bonded to in order to stabilize it and assist in the absorption. Between most of the different forms, they are absorbed quite well and there isn’t a very large difference between the absorption of each one of them, but different people have different preferences so we have a variety of different options to suit those requests.