Pro Keto RX Studies on Hoodia conducted by the global scientific community have revealed that Hoodia Gordonii is an effective weight loss supplement due to its ability to suppress appetite. Pharmaceutical companies have reduced the active ingredient in Hoodia that is responsible for weight loss. P57, as it is commonly known, is considered the key ingredient in Hoodia Gordonii that works by activating the part of your brain that is responsible for hunger and tricking the brain into thinking that it is full.