If its still puzzled you why some people loss weight easily while some other people also gain weight easily, the answer would really depends on the persons way of living. Will you blame it to the medicines you are taking if you won't get that weight you are aiming to burn in time? I think its too unfair if you are going to pass the blame, when in fact you are not also doing your part aside from taking the pills inside your body. In my own opinion, to achieve fast weight loss for your body, you must also do some sacrifices than just put your hope on that tablets you are taking, which promises the consumer , weight loss. We all know the basic rules ; exercise and discipline and diet. And if these factors are open to you, You'll see the rest will follow. Good luck!