You could call it the anti-Jolt, except that it does contain caffeine. It also has vitamins and minerals, including thiamine and potassium. It's a product of Tennessee, has been around for years, and apparently was touted for its medicinal properties back when the FDA didn't exist or would let you get away with it.
You can find it in Southern convenience stores. And, scarily enuf, they've got a website now (coming soon, anyway) at http://www.drenuf.com.
It's not a very good name, is it?