MDMA has 100% changed, not the compound persay but certainly something like generating different impurities or something on a level we can't see.
I've had amazing MDMA 10 years ago, 100mg would have you rolling hard for hours on end and little redose to keep it going.
But when you give multiple first timers 100mg now, they aren't rolling anywhere near as hard not to mention want to re-dose constantly because it's just not enough.
There is good batches however, I had one 2 years ago and was perfect, not as euphoric as the first times but not expecting to be but certainly rolling hard and for many hours no re-dose required.
It's interesting that all these other drugs you can abuse them, stop for 12 months and it will be super potent again but MDMA these days, not a chance. - something weird going on for sure.