When I worked 3rd shift I'd get drowsy on the drive home, if I was feeling tired at lunch time I'd drink a 5HE and it would get me home without falling asleep at the wheel. By then it was almost done and I'd go to bed as soon as I got home. Never made me jittery but I wouldn't drink them on a daily basis. Tastes AWFUL which is probably a good thing. I'd never use them when doing strenuous activity though.
__________________
".....distasteful and easily triggered."