I think they are like zotrim! They swell in tummy and therefore give you that full feeling after eating less food. I think if you eat low cal ,because you are hungry, they may work. Would we be overweight to start with if this was the case? We either eathigh cal food, or eat for many other reasons other than because we are hungry, or both! In which case appetite suppresants don't really work.
I've tried the normal, green packet, adios tablets, a couple of years ago, and I think that they were a waste of money tbh, a placebo, but if they work then that's good enough for anyone!
In my experience, they didn't make a difference tbh.