Although hoodia gordoni products are freely available in the US

Although hoodia gordoni products are freely available in the US, Canada, England and Europe it is currently not as easy to purchase hoodia gordoni in Australia. 

There are two reasons for this: 
The Therapeutic Goods Administration (TGA) have not approved any Hoodia products to be sold from within Australia. The weight loss claims for Hoodia are a therapeutic claim, which mean that it needs to go through the TGA approval process which can be quite lengthy and expensive. Therefore anybody claiming to be legally selling a hoodia gordoni product from within Australia is making a false claim. There are currently no hoodia gordoni products listed with the TGA. 

The Department of the Environment, Heritage, Water & The Arts monitors the import of Hoodia products. Why would they do that? The reason is that the hoodia gordoni Cactus is a protected species due to it's popularity and they need to ensure that the Hoodia is sourced from a legal supplier. That supplier must have what is known as a valid CITES certificate (Convention on International Trade in Endangered Species). Additionally, the purchaser must have a valid CITES import certificate, obtained from the above Department. A purchaser only wishing to order a small amount of this product may find this requirement prohibitive. 
Hoodia in The Media

hoodia gordoni has become very widely known due to it's appearance in the media on such shows as Oprah, Barbara Walters and other mainstream American media. 

CBS News
"Each year, people spend more than $40 billion on products designed to help them slim down. None of them seem to be working very well. Now along comes Hoodia. Never heard of it? Soon it'll be tripping off your tongue, because Hoodia is a natural substance that literally takes your appetite away."(Read the whole story). 

NBC Today Show
"It's the look everyone wants — a body to diet for. They're on the beaches, in magazines and all over Hollywood. How far will we go to get one? How about thousands of miles and deep into a distant culture? South Africa’s Kalahari Desert is home to what could be the answer to an appetite.

It's a cactus called Hoodia. 'You strip off the skin, you strip off the spines, and then you consume it,' says weight loss expert Madelyn Fernstrom." (Read the whole story)

National Geographic
"Africa's Bushmen May Get Rich From Diet-Drug Secret... The drug named P57 is based on a substance scientists found in the desert plant Hoodia gordinii. The San call the cactus !khoba and have been chewing on it for thousands of years to stave off hunger and thirst during long hunting trips in their parched Kalahari desert home.. A deal has been signed between the South African San Council and the country's Scientific and Industrial Research Council (CSIR), which identified the appetite-suppressing ingredient in Hoodia during research into indigenous plants in 1996..."