I've always developed tolerance to stimulants very rapidly. Of the stimulants I've tried, I'm very sensitive to my initial dose, then subsequent doses do nothing without abstaining for a significant amount of time. For example, yesterday I took a half dose of an EC stack; 12.5mg of ephedrine, and 100mg caffeine. That one half dose lasted all day and had me strongly stimulated. I had great focus, plenty of energy, and actually got something done at work. It was about as stimulated as I could be before side effects would be bothersome.
Today I took a full dose. That's 200mg caffeine and 25mg ephedrine. Then I took another full dose four hours later. I feel only slightly more stimulated than if I had taken the caffeine by itself. This kind of tolerance has happened my whole life.
Stimulants that have demonstrated tachyphylaxis in me:
Ephedrine with caffeine
Phentermine
Modafinil
Stimulants that haven't
Caffeine
Methamphetamine
I know the list is small, but I'm not really a stimulant user. I can't be, most of them poop out after only one day. I only used the methamphetamine fore about three days, because I really didn't like the idea of taking methamphetamine. I did notice a slight tolerance beginning to develop, but not the single dose tolerance like other stims.
Its seems the stims that cause this problem in me tend to be more adrenergic. Ephedrine is actually specifically mentioned by wikipedia as a supplement that can cause tachyphylaxis. Supposedly it drains the bodies noradrenaline and adrenaline stores quickly. What can I do about this? Will taking phenylalanine or tyrosine help? What about a COMT inhibitor? Could I be over methylated?