I need something to help me lose some weight.....?

Let me rephrase that I need something to get me started. I have started dieting and exercise but I have horrible pain in my legs and lower back so I would like to take something ( I know there's no miracle drug) just to kinda get me started to maybe take a little bit of weight off to help make it less pain full. anything either over the counter or prescribed. Thanks. This is not something I want to do for long but like I said just a jump start to go along with my diet and exercise. Thanks