The only way to be absolutely sure you are getting quality pure Hoodia, is for the manufacturer to provide an independent lab report verifying the origin and quality of the Hoodia Extract. While it is always possible to forge such document, most manufacturers won’t risk the legal implications and will just not supply one if their product is of low grade. Companies selling quality Pure Hoodia will present such document in a prominent place on their website.
Alkemist Pharmaceuticals are the leaders in the Hoodia testing field, and most suppliers provide a report of testing performed by them.