I have doubts. Currently, genuine hoodia gordonii (the type of hoodia that contains the molecule P57 responsible for appetite suppression) is illegal for export from Africa. There are tons of so-called real hoodia products on the market, but none have been found to contain genuine P57. I guess if they did, then they couldn't sell it because Phytopharm owns the patent to P57 and no one else can sell it as a weight loss product. Also, a major pharmaceutical company, Pfizter, in agreement with Phytopharm spent millions of dollars trying to put hoodia P57 into a pill format that would be effective, but failed and left the project. Unilever then joined with Phytopharm and may have a food product available later this year or next that may be useful but they are still testing it to make sure it's both effective and safe.
It's a long story, but there are a lot of reasons why so-called hoodia products should be avoided. In the meantime, the products that claim to contain hoodia don't actually contain p57. Instead, they contain various other ingredients such as cheap fiber.
When the real thing is finally available, we'll spread the word

Until then, the only way to get the benefit is to get your hands on a fresh chunk of hoodia gordonii plant and eat it. In fact, they say that's the only way it's been proven to really work - by eating it fresh - and you have to eat a chunk about 4 inches long.