I've heard lately that Trimspa and Cortislim are effective "diet pills."
 Of course, I'm wary of any solution that promises weight loss with
the ingestion of a tablet.
 I know they're not FDA mandated, but have there been any independent
studies of the safety/efficacy of these two products?

Trimspa seems to work mainly by caffeine (and theobromine, which is
10x more powerful than caffeine), citric acid, and fillers. Cortislim
also works by these methods, but with less fillers, and supposedly a
natural herb that controls cortisol. In effect though, the three
things mentioned above are the main way that each causes weight loss.