Ismene said:This number will depend on the individual's body, but also the frequency with which they use.
I disagree. I think the by far the most important thing is the quality of the drug and how you are feeling at that moment.
That will affect the quality of your roll, and it's entirely condusive the good, bad, and mixed experiences we've all had on MDMA (I told a beautiful girl friend of mine that the bad roll she had the other night will teach her many things - she txted me back this morning to say I'm right

But in terms of tolerance it still makes a difference. It's still your brain (and psyche) becoming adjusted to MDMA that little bit more. Talking from a physical/medical stance it still rings true.