Glucuronolactone (Glucurolactone) is a key ingredient included in many popular energy drinks.It promotes improvements in alertness as well as physical performance. Glucuronolactone is a naturally occurring metabolite of glucose. It is ‘ergogenic’ in that it is designed to enhance physical performance. Clinical studies on energy drinks, such as Red Bull®, have shown that they:Improve physical (aerobic and anaerobic) performance; Increase alertness, memory recall and focus;Improve reaction times. A Chinese study found that a herbal supplement containing glucuronolactone, resulted in a marked improvement in patients with hepatic fibrosis resulting from Hepatitis B.