Get a hobby is correct, most of the stuff you get at health food stores is crap. If you would like to try NAC and want to make sure you a getting what you paying for, ask your doctor to prescribe 20% mucomyst solution to get 1800 mg you would do 4.5 ml twice a day. If he's stubborn and won't go outside the box here is the link for the stuff they used in the Stanford study (<a target=_blank class=ftalternatingbarlinklarge href="http://www.bioadvantex.com/us/02_ghealth_pharmanac.asp">http://www.bioadvantex.com/us/02_ghealth_pharmanac.asp</a>).