I have not and would not go to therapy under the influence of a party-drug and do not advise doing so. Considering ecstasy is a stimulative, I don't see how you would benefit from going to therapy while high on it. Maybe if your session took place in a rave, but I somehow doubt that is your situation.

I definitely would not recommend going to therapy on any empathogenic that you have never taken before. That is bad, bad, bad news bears. Always have a babysitter. Preferably one that knows you're on ecstasy.

I sometimes take opiates before appointments. It makes me more authentic, but I would not recommend that either. How your body reacts to different drugs is unique to you and someone else's experiences have no relevance to what your experience might be.