500 calorie diet is it safe?

HCG is a shot u take everyday , when u take the shot u can only eat 500 calories a day! the good thing about this diet is that u can looses about 1 to 2 pounds per day ... it sounds to good to be true but it actually works i want to try this cause i do need to loose weight but i don't know if i should try it what do you think ??/\?