You don't feel anything
That blows my mind. Back in the day I was a big crack smoker( 15 years ago).
No I ain't joking, I cry when I think about the rehab bill.
Xenadrine is some strong sh@#. I take 2pills when I wake( 7:30) and 2 pills 2 hours before workout ( 3:00). It been 2 weeks and I get extremly wired and tweaked out. I don't start to mellow out until 10:00 at night.
I have a pretty good tolerance to caffine its the ephedrine that has been kicking my ass. Like some other posters said ephedrine raises blood pressure among other things. If your are de-sensitized to the stimulus the product is still working to assist burning fat.
I would not reccomend increasing the dossage. High blood pressure combined with the blood thinning of asprin with intense workouts is a good recipe for a heart attack. ECA scare me and they should scare you too.
If you wan't to increase the stimlus increase the caffine dosage do not increase the ephedrine dosage.
Please keep in mind that increase usage of stimulants is not good for you either. If you have built up a hughe tolerance to stims maybe its time to lay off for awhile. Just my 2 cents.