We've heard horrible things about it. It can be very dangerous and it's illegal since the FDA has banned it for weight loss.
Also, it's used with a 500 calorie diet, so you basically starve the weight off. A study done on it showed that following a 500 cal diet with HCG was no more effective than a 500 calorie without it. It's still just starvation. Also, the weight comes back very quickly when done. That's probably why you've had problems with other very low calorie diets.
A slower and more nutritionally balanced approach is healthy, safe, and long lasting
Please feel free to browse around our forums and check out some of the diets our other members are following with success. Hopefully you can find a good fit for you. Good luck