NAC does not cause rash or flushing as Niacin. Men on high doses of testosterone have low HDL.
Pharmacol Res. 1993 Oct-Nov;28(3):213-8.
Dose-related increase of HDL-cholesterol levels after N-acetylcysteine in man.
Franceschini G, Werba JP, Safa O, Gikalov I, Sirtori CR.
Centre E. Grossi Paoletti, University of Milano, Italy.
Changes in plasma lipid-lipoprotein levels were evaluated in 10 hyperlipidemic patients during treatment with progressive doses (from 1200 mg day-1 to 3600 mg day-1) of N-acetylcysteine (NAC). Plasma total cholesterol and triglyceride levels, as well as those of lipoprotein (a) did not change to an appreciable extent, even with the highest dosage. However, the HDL-cholesterol levels showed a significant, dose-related rise, the mean absolute increase, with the highest NAC dose, being of approximately 10 mg dl-1 (16.2%). The rise of HDL-cholesterol was independent of changes in other lipid-lipoprotein parameters, suggesting a possible direct effect of NAC on the HDL system.