when i switched from one pill to another i gained quite a bit of weight, i mentioned this to the dr and she said that the pill doesnt make us put on weight, its due to how much we eat, BUT looking at side effects, some pills can increase your appetite so obviously, you are going to eat more! Its just a case of thinking if you are eating more than you used to! I actually lost the weight when me n my boyfriend were having a rough patch, i lost nearly a stone in a week (about as much as I'd put on) but found that i thought i looked a bit gaunt, probably due to the fact i lost it so quickly though! but have put it all back on again now, am trying to exercise more rather than eat less!