Within your brain, you have several distinct parts. Each part of your brain has a job. The hypothalamus of your brain is the part which, as one of its jobs, sends signals telling you whether you are hungry or not, and in which there are nerve cell receptors that sense your blood sugar level. When you eat, your blood sugar level rises, signals are sent to the hypothalamus, the nerve cells fire, and your hypothalamus tells the rest of your brain and body that you are full. This is why it is best to eat slowly, if you eat too fast, your body does not send the signals in time, and you over eat.
Slow eating is also a good way to ensure you are only getting the amount of food you actually need to be full.

With Hoodia, the active molecule in it sends other chemicals to your hypothalamus which sets off the nerve receptors, convincing your brain and body that you are full when you may not have even eaten. This effect can last for some time, depending on how much Hoodia you have ingested.

Hoodia seems to work best in its natural form, but drug companies are trying to make synthetic versions, and have not yet been successful. Pills are available which contain some natural Hoodia, but you should check where the Hoodia is coming from. It should be South African Hoodia. The pills contain a lower dosage of the natural ingredient which suppresses appetite than eating straight Hoodia contains, but will still work to suppress appetite, just for a shorter period of time. In some people, appetite is not suppressed as well because while the brain may think you are full, the body will still need calories. As a weight loss method, Hoodia works best when combined with a proper diet and some light exercise. The exercise will help your body use up even more calories, causing it to need to burn fat into sugars in order to give your body the necessary energy.

Some people have had success when combining Hoodia with the Atkins diet. It seems that combining small portions of healthy food with an appetite suppressant may be the most effective use of Hoodia. Other people, however, have reported little or no effect from the Hoodia supplement they were taking, and that they did not lose any weight at all.