Glucuronolactone or Glucurolactone (INN) is a naturally occurring substance that is an important structural component of nearly all connective tissues.

[2][3] Unfounded claims[4] that glucuronolactone can be used to reduce "brain fog"[5] are based on research conducted on energy drinks that contain other active ingredients that have been shown to improve cognitive function, such as caffeine.

[6] Furthermore research on isolated supplements of glucuronolactone is limited, no warnings appear on the Food and Drug Administration website regarding its potential to cause brain tumors or other maladies.

The Panel also concluded, based on the data available, that additive interactions between taurine and caffeine on diuretic effects are unlikely.

[10] Glucuronolactone is approved in China and Japan as an over-the-counter "hepatoprotectant",[11][12][13] though there is a conspicuous lack of systematic reviews on this use.