Vivus' Qsymia uses a mixture of pnehtermine and topiramate. Phentermine is an anorectic, which is defined as something that suppresses appetite. More specifically it is a cousin of the amphetamines. It is this trait that has some investors worried about Qsymia due to the potential of a cardiovascular event for patients using amphetamine-like drugs. The other compound is topiramate, which acts as a mood stabilizer hence its use as an anticonvulsant, which targets the addiction part of obesity. It's no secret that Jonah Hill has been working hard to shed some weight, and the '21 Jump Street' star showed off a svelte new figure at the ESPY Awards Wednesday night.