Glucuronolactone is a popular ingredient in energy drinks because it has been shown to be effective at increasing energy levels and improving alertness. Glucuronolactone supplementation also significantly reduces "brain fog" cause by various medical conditions. Although levels of glucuronolactone in energy drinks can far exceed those found in the rest of the diet, glucuronolactone is extremely safe and well tolerated. The European Food Safety Authority (EFSA) has concluded that exposure to glucuronolactone from regular consumption of energy drinks is not a safety concern. The no-observed-adverse-effect level of glucuronolactone is 1000 mg/kg/day.