Hi everyone!
If you're trying NAC, give it a month before making up your mind. If you see no improvement, either up the dosage to 1200 mg, divided, (if your taking 600 mg) or else quit it. After a month, I would not stay on 1200 mg of NAC if I was getting no response. None of these supplements have been studied long term. It's always best to error on the side of caution.
NAC is just an aid; but it does help some people. Like most supplements, however, it won't help everyone. And I'm not even sure if it's effects will lessen over time. Magnesium used to quiet me; now, it doesn't. Only time will tell if NAC will keep my tinnitus lower.