I am still doing the NAC. For about 6 months I'd been taking it off and on with no trouble. However, Oct 8th I began to take 600mg every morning without food. I became miserable. Increased depression. Myalgia arms, back hitting strong... Arthralgia - Lt hip, Rt knee. Nausea at times. Stopped it Oct 25.Oct 28th decided to try smaller dose. Took about 150-200 each morning. Still symptoms above but decreased frequency and intensity. Keeping at that dose for now.At this rate it will take a long time to get to 1200mg/day which I think is the recommended dose before starting antibiotics.