The HCG Diet is effective, but only with the injections or sublingual tabs, not the drops. The protocol is a strict 500 calorie (specific foods) diet. Of course 500 calories a day will cause weight loss, but there's something about the injections/tabs that "resets" the the hypothalamus or something which prevents regaining the weight back and retains muscle tissue. There's a minimum and maximum amount of time to be "on". I have a couple of friends who've done it and it's worked for them. They said the diet is not for wimps.