There is no clear information on how much hoodia is necessary to reduce appetite. Anecdotal reports suggest that 2 ounces (60 grams) or more per day of the crude plant may be necessary.

Hoodia is a slow-growing plant that thrives in a relatively limited geographical area. Given the potential for becoming endangered due to high demand, there are strong regulations in place (based on the international treaty called the Convention on International Trade in Endangered Species) blocking its export. It is presently unclear if any supplements available in the US reliably contain Hoodia gordonii and how much would have to be taken of them to be useful. The Phytopharm company says they have a plantation to sustainably grow hoodia for the product they intend to release someday, but this product is not yet available.