amphetimines such as ephedrine or its isomers have been used and known to dicrease appetite. Along with caffiene, ephedrine is known to releases fatty acids into the blood stream where they can readily be uptaked by working muscles to be burned. This can provide energy especially when dieting. The increase in fatty acids may allow for an energy source other than the bodys own proteins when glycogen stores are depleted providing a muscle sparing effect when in a catabolic state. Increasing magnesium blood levels may also slow the excretion of amphetimens and may be used to provide a longer lasting effect. Caffine and ephedrine have also been shown to significantly increase maximum cycling efforts in individuals and may allow one to train longer, in effect buring more calories speeding up the weight loss. So yea, there might be a pill to help you loose weight.