Why does ecstasy cause you to clench your jaw?

Answer 1

Ecstasy is a stimulant to begin with, and Ecstasy pills are often cut with some form of speed, or sometimes cocaine. Stimulants give you a lot of nervous energy, which can cause you to tense up and clench your jaw and/or grind your teeth.

Answer 2

Jaw chattering or clenching on E is due to stimulation of the trigeminal nerve. While it's really common while high, it does not last long.

Answer 3

It's a natural impulse for people to grind their teeth