It's good at appetite suppression, but I do get acclimated to it. This is okay, you don't want to be dieting forever. I'd start at 2 1/2 tabs (20mg) 3x day with caffeine at 200mg per dose, then after a month- 2 months I will not get the same kick at all from it, feel demotivated, lack enthusiasm (basically normal when you're eating a deficit of kcals and doing plenty of cardio).
I just increase to 24 mg. When that fails, 28. Never rushed to up the dosages, and never exceeded 36mg per dose (I can't imagine having to, dieting is usually done long before that).
Then I cut out the E, leaving only the C at 200mg 3x day while removing the doses back down, only much quicker this time, for example 32mg for 3 days, 28 mg for 3 more days, etc etc, so you don't suddenly have raging hunger/ no energy when ending the diet. Works well