My previous company, a pharmaceutical company specializing in hormones, has been seeking an obesity (bad word when they're really working to develop products for weight loss) franchise for almost 20 years.
Because of my knowledge of many of the factors that go into weight loss and losing weight, I generally caution against diets unless you're working with a dietician.
I couldn't find any good, reputable websites who endorse the HCG diet which makes me pause. People had much success with low-carb plans, but the diets are hard to maintain in the long term.
Not knowing much about it, I'd recommend finding something different that is medically advised. Even a treatment for dissolving fat which has been on the market for several years and administered through physicians received a warning from the FDA last week because of no compelling data to support its effectiveness.
Good luck! Depending on your goals, I hope you find the right plan to get you there.