The lethal toxic dose is 30gms/day. I take 3-4 gms/day. The amount that you guys are taking does not give the same level of effect that a multigram daily gives. I was in full ketosis even on the days that I ate large amount of carbs. You will never see that with just taking 600mg/day. To me the proof is in the pudding. I used to take ALA at the dosage you did, and never managed to lose 17 lbs of fat in 1.5 months, just with moderate dieting and NO cardio.
Remember when creatine used to come in 500mg caps? And people took 2 or 3 caps and essentially nothing happened? Same thing. Until some one said let me try a damn teaspoon full of creatine, and the rest is history.
This has been my observation and experience on it. Your mileage may vary. I take enough ALA to get a moderate hypoglycemic state which when combined with weight training and moderate dieting is highly beneficial to fat loss.
Rangerx83 (AKA RockHard)