 [ Symptoms ] why does birth control cause you to gain weight  i started birth control just 1 week ago and i have already gained 4 pounds my eating is the same and so is my exercise so why am i gaining all this weight is it water weight if i stop taking the pill can i easily lose the weight [ Disease ] hi your find that the odd women get one my wife has one to its just something that you will have to live with its there for the rest of your life good luck