HCG is a hormone that is found exclusively in pregnant women, and it turns out that it can also help you get pregnant. In the 1950s, Dr. A.T.W. Simeons discovered that hCG helps people lose weight by allowing them to eat less without feeling hungry. Based on this, he started the hCG diet, which involves a 500-calorie-a-day diet for a maximum of 43 days while being injected daily with hCG.

The Food and Drug Administration has not approved the use of hCG for dieting (or any reason other than fertility), but you can still get it with a prescription from your doctor. Since insurance doesn't cover the hCG diet, it can get pretty expensive. A visit for your initial consultation may cost you around $150, and then you'll probably have to have to pay about $10 for each injection on top of that. Some versions of the diet also encourage the use of appetite suppressants, including daily injections of stimulants, such as phentermine. If you're going to add these to your regimen, you'll have to factor in the price of them as well. Then, of course, you'll have to pay for any follow-up visits. And if you don't lose sufficient weight when you do the diet, after a six-week rest period your doctor might recommend you do it all over again.

While there have not been too many reports of health problems that have developed from the hCG diet, keep in mind that following this diet will give you an increased risk of headaches, blood clots, restlessness and depression. In addition, the hCG can give you pregnancy-like symptoms, such as water retention, breast tenderness and swelling. And finally, hCG can also cause a condition called OHSS, or ovarian hyperstimulation syndrome, which is potentially life-threatening. Keep all these things in mind when deciding whether or not you want to try to lose weight using the hCG diet.