I've heard nothing but bad things - it causes a lot of bowel problems which are both inconvenient and potentially dangerous. Every time one of these diet pills is pushed onto the market, a lot of people get sick and then eventually it is recalled. If a product isn't stimulating the central nervous system, it's causing intestinal issues.
There are other safe ways to lose weight but there's no magic in a pill form, that's for sure.
I use something for blood sugar management (I'm not diabetic but I do have metabolic syndrome), but it went through clinical trials and the company is not spending its money on an expensive celebrity spokesperson and a whole bunch of commercials.
A lot of supplements have been debunked in the press lately - most don't work, or they contain harmful ingredients, or both. It's best to look at a total program of exercise, portion control, increased fiber, and, if you use a supplement, use something patented and from a company that is part or, or recommended by, the Council for Responsible Nutrition. That rules out most companies.