MPA gives you energy (until, of course, it runs out). This will boost what you are doing - if you are creative, you will do that for longer (singing, dancing, writing, painting, etc.). If you are not being creative but just doing the dishes, you will get the dishes done (or you will start many other kitchen related tasks).
Wikipedia says MPA is "very hydrophilic". A hydrophile is a molecule or other molecular entity that is attracted to, and tends to be dissolved by, water. This could be why you have a dry-mouth, but I'm just speculating. (Relatedly, MPA is apposite with alcohol.)
MPA makes you sweat & thirsty. It may change the odour of sweat & other fluids (due to the sulphur in it, perhaps?). As has been attested to many times above, the chemical has a strong stink.