The effect has me completely by surprise. On the first day I thought, without exaggerating, I would have taken a "doping agent". Not that I would have with this kind of experience but a burst of energy was there immediately. By now I've gotten used to this new state. The difference from before is no longer so extremely noticeable but I feel a whole lot better. I have more strength, feel more comfortable, am much more alert and concentration is also increased.
This is obviously a "single individual result" as the saying goes, but I can only recommend the health problems OPC has a try.