If you’re used to caffeine there seems to be some kind of rebound effect in some people - first it makes you hyperactive and increases alertness, but after some time the effect changes to the opposite, and some might even feel tired paradoxically. But this applies only to some people, as the caffeine sensitivity varies extremely between individuals.
Maybe it is also possible to get used to caffeine. I am just not sure whether everybody can decrease his/her sensitivity to caffeine. Is there something that one can do to decrease one’s caffeine sensitivity?
I love coffee. I can’t give it up in any way, even though I know it’s not very healthy. But now I only drink one cup a day, and I used to be able to drink three cups of coffee.
Research has credited regular consumption of coffee to reducing several risk factors in diseases such as degenerative brain disease and memory loss[8], central nervous system disorders[9], gallbladder disease[10] and Parkinson’s disease[11], as well as improving liver health[12), improving glucose balance and type 2 diabetes control[13], reducing mild depression[14] and improvements in body composition[15]. Correlation has also been made to coffee consumption and the reduction of some cancers such as colon, liver, endometrial and pancreatic cancers[16]. There is also a wealth of research to suggest that coffee consumption also reduces the risk of strokes and heart disease[17, 18].
Caffeine does seem to have some benefits with regard to some neurological diseases.
But it can cause anxiety in psychological conditions or sensitive individuals.
And it disturbs sleep if it is consumed too late - caffeine containing shakes or drinks seem to be bad as a dinner; not only for sensitive individuals.
That’s why I would suggest to keep all flavours caffeine free. If someone wants caffeine it is easy to add it - but it is impossible to subtract it.