Glucuronolactone is a naturally occurring chemical compound produced by the metabolization of glucose in the human liver. It has received some notoriety due to rumors that it was a Vietnam War-era drug manufactured by the American government. The rumors go on to say that it was banned due to several brain tumor deaths at the time. These rumors are not based on documented facts. Some of its positive benefits have been known to include acting as an antidepressant, stimulant, and helping in memory retention and concentration. It is present in some energy drinks such as Red Bull and Pollen Burst, as it is a precursor to taurine.

Glucuronolactone is a popular ingredient in energy drinks. Most of these drinks contain caffeine, but glucuronolactone is included because it is purported to fight fatigue and provide a sense of well-being. I was not able to find a human study that evaluated the effects of glucuronolactone on mood or energy when provided just by itself.

Basically, Glucuronolactone is a naturally occurring human metabolite formed from Glucose, so we can discount the bizarre Vietnam LSD Jacob's Ladder style connotations. It occurs in many other substances (including wine), but not in anything like the doses found in Red Bull. ("Based on this USA estimate, daily intake of glucuronolactone by regular consumers of two 250ml cans of energy drinks containing 2400 mg/l could exceed intake from other food sources by up to 500-fold")