ECA stack making me tired???

[ThaChunk]

Towards the end of my bottle of ThermogenXS I noticed shortly after i took it i got tired. This really confused me as it contains 200mg of caffine which should wake me up. I thought that maybe i had developed a resistance to caffine or something similar? Is anything like this known of or could it be something else?

[Speedfreak]

You could've been on it long enough to get addicted. And yes, the body does adapt to it.

http://www.atlantadentist.com/Caffiene.html