I just recently went back on MSM after a 2month break. My doctor recommended 1500 mgs 3 x's day. That along with Sun Chorella and L-glutathione that had NAC mixed in it, on top of Metagencis "Adva Clear- Liver detox supplement" were too much. Now am on 500 mgs 3 x s day and 1 l-glutathione pill per day. Had to ix-snay the sun chlorella,we just dont get along. Noticed an energy difference with the MSM though. Need to find small doses of L-glut and NAC though, too "ampy" feeling.