The hCG diet sounds tempting, doesn't it? Lose 30 pounds (13.6 kilograms) in a month -- and all you have to do for those results is be injected with the hormone hCG (human chorionic gonadotropin), which is extracted from the urine of pregnant women. Oh, and in addition to that shot, you're only allowed to consume 500 calories -- and that's per day. Considering the average American adult male consumes more than 2,600 on an average day, that's going to hurt -- literally. You'll have stomach pains from near-starvation eating this way, and daily caloric intake this low qualifies as anorexia nervosa, which can cause damage to every organ system in your body.
The problem, though, aside from starvation, is that there is no evidence that injecting yourself with hCG is a viable long-term weight-loss solution -- and hCG is only approved as a way to treat infertility, not as a way to lose body fat. All hCG products are supposed to come with a warning that they aren't intended as a way to lose weight, as an appetite suppressant or as a way to melt hard-to-lose fat; but, frankly, whether the injection works or not, a diet with calories this restricted will cause weight loss regardless of the hCG.