What is hoodia? According to dietary sources, it's a pill you take to lose weight. But where does it come from?

Hoodia is a member of the succulent family Apocynaceae or dogbane. According to Wkikpedia:

Several species are grown as garden plants, and one species, Hoodia gordonii, is being investigated for use as an appetite suppressant.

ExcellentWeigh Blogspot has this to say about Hoodia pills:

According to Phytopharm, the company that holds the patent on the process to extract 'P57' an active ingredient from hoodia, human subjects taking hoodia roots reduced their calorie intake by as much as 2k calories a day. So figures are impressive, and so far the overall results are satisfactory.

The big question - Is hoodia safe to use? An article I found in Ezine Articles entitled The Truth About Hoodia Safety
What we know about it is that the Sans Bushmen, a tribe that lives in the the Kahalari Desert of South Africa discovered hoodia and have been using it literally for thousands of years to suppress their appetite with no known negative side effects.

We also know that the active ingreident in the hoodia plant responsible for its ability to diminish the appetite -- called P57 -- was used in a study with morbidly obese participants by the pharmaceutical company Phytopharm and caused weight and fat loss in the participants using it with no discernible bad side effects.

However, the article goes on to list several cautions and suggests that more testing is required before a decision on the safety of hoodia is made.