NAC 1200 or 2400/day?

Hello folks, can anyone clarify whether the recommended ramped up dose of NAC is 1200/day (i.e. 600 X 2 per day) or 2400/day (1200 x 2 per day) or other?  I have checked the formal list of supplements (chart) which shows the 600 X 2 per day but I read in many posts about ramping up to the full 2400 mg dose (presumably acceptable as 2 doses of 1200 each?). 

Any suggestions as to rationale for lower versus higher maximum dosage?

Thanks for your input!  Regards, Len.

2400 a day is what we take, and have for years.

Rica

3/9 Symptoms returning. Began 5 abx protocol 5/9 Rifampin 600, Amox 1000, Doxy 200, MWF Azith 250, flagyl 1000 daily. Began Sept 04 PPMS EDSS 6.7 Now good days EDSS 1 Mind, like parachute, work only when open. Charlie Chan  In for the duration.&am