I just did this diet but not all the way through. First poster below sent you to a wiki site BUT it is not for the TRUE HCG diet. That is for the Dr. Kevin Trudeau book that he wrote and added soooo many things to it.
The orginally HCG was developed back in the 70s from Dr. Simmeons. There is the 23, 43 and 63 day diet. You follow the diet to a T. There are only certain veggies, fruit and meats allowed. I did the diet for 23 days and lost 20 pounds. I stopped because there was only 3 veggies i ate on the list of 15 and i couldnt take another cucumber!!! My mom just finished her 43 days and went from a size 14 to an 8. No muscle mass loss etc...
Our Dr even endorses it. To the 2nd poster. YES you are only Consuming 500 calories BUT with each shot it breaks off 2,000 calories for your body to burn off of the fat wall of your body. So your body is consuming 2500 calories.
Those that are generally against this diet are either A hearing bad negative feedback from the B people that are into other "weightloss" stuff that are bad mouthing it.
Simply put ask someone who has done the program and they will tell you it works. www.hcgdiet.com read up there. Cheapest place to order from and it is out of Arizona. (most places are out of country)