What is Glucuronolactone? Glucuronolactone is a key ingredient included in many popular energy drinks. Research has shown that it promotes improvements in alertness as well as physical performance. Glucuronolactone is perfect if you’re trying to increase your training intensity, or even if you’re just looking for a ‘pick me up’ during the day. Glucuronolactone is a naturally occurring metabolite of glucose. It is ‘ergogenic’ in that it is designed to enhance physical