I agree
Seriously had great results with Xen, started using it more and more though to feel and eventually I realized I was just wasting my money. Started buying all these different brands (thought it was the Xen, not me)--again realized I was just wasting money. Quit taking--like a year later was reading somewhere on the supp forum and everybody was talking about MD6--I bought some, never even seen the original version everybody raved about but still had great results. After two months, stopped working.
I did alot of research. They work by stimulating your adrenal system but over time, you will burn out the sensors that detect the ingredients. Plus your body adjusts to the stuff and reacts less and less the longer you stay on. You can either take more and more until you break the whole process or give them time off to resensitize. Similar to insulin resistance, just different parts.
Different people have different time frames though I'm sure--some people might get away with a longer cycle, some with less. As for me I'm sticking with the 6wk on/off plan, works pretty well.