Here is an excerpt from a BBC media piece:

At about 1800hrs I ate about half a banana size (piece of hoodia gordonii)-and later so did my cameraman.  Soon after, we began the four hour drive back to Capetown.

The plant is said to have a feel-good almost aphrodisiac quality, and I have to say, we felt good.  But more significantly, we did not even think about food.  Our brains really were telling us we were full.  It was a magnificent deception.

Dinner time came and went.  We reached our hotel at about midnight and went to bed without food.  And the next day, neither of us wanted nor ate breakfast.
 

Tom Mangold, BBC News May 2003


HOW HOODIA WORKS IN THE BODY.

The component molecule P57 in the hoodia imitates the effect that glucose has on nerve cells in the brain.  Hoodia, in effect, fools the brain into thinking it’s full when it’s not.  This mitigates your desire to snack and eat unhealthy food.  

Here’s another piece that BBC News did regarding P57’s impact on the brain:

“There is a part of your brain, the hypothalamus.  Within that mid-brain there are nerve cells that sense glucose sugar. When you eat, blood sugar goes up because of the food, these cells start firing and now you’re full.  What the hoodia seems to contain is a molecule that is about 10,000 times as active as glucose.  It goes to the mid-brain and actually makes those nerve cells fire as if you were full.  But you have not eaten.  Nor do you want to. I ate lunch but without appetite and very little pleasure.  Partial then full appetite returned slowly after 24 hours.”

Tom Mangold, BBC News correspondent – May, 2003


There have been no reported side effects reported from consuming hoodia or from the P57 molecule.  For thousands of years the san bushmen have eaten hoodia gordonii plants with no negative health effects.

So with hoodia, we can just stop eating? Of course not.  We need to eat to survive. You can’t completely starve your body no matter how much hoodia you eat, and weight loss doesn't mean anything if you're dead.  Your brain will figure out that you do need food to function.  The key point here is to keep you from OVEReating.

Feeling hungry because your insulin levels are bouncing all over the place is
called hormonal hunger.  It is this hormonal hunger which causes havoc with most people’s dieting efforts.  When blood sugar levels spike up, we begin to crave more sugars and carbohydrates.  Your body goes into withdrawal. This is why people crave ice cream at midnight, and pregnant women crave crazy foods.

The concept behind hoodia gordonii is to use it as a tool to stop snacking and overeating because of hormonal hunger.  You want to continue to eat meals when you have real hunger, but eliminate the overeating because of hormonal hunger.  If you eliminate the cravings when you really don’t need any food, you can lose weight rapidly because your body has all the energy it needs to function with a much lower calorie count.