8-Hydroxyguanosine (8-OHG) is an oxidized form of guanosine produced when reactive oxygen species attack RNA. It belongs to a class of modified nucleosides generated during nucleic acid oxidation and normal RNA turnover; these modified bases are released and excreted, making urinary 8-OHG a noninvasive biochemical readout. Oxidative nucleoside markers were developed to study molecular damage from environmental and metabolic stress. Measuring 8-OHG complements DNA oxidation and lipid peroxidation assays by specifically reflecting RNA-related oxidation processes that can affect protein translation, signaling, and cellular homeostasis.

Higher urinary 8-Hydroxyguanosine is associated with increased RNA oxidation and greater oxidative stress burden, which can reflect elevated free radical production, mitochondrial inefficiency, inflammatory signaling, or exposures to oxidants. Lower levels generally indicate lower measured RNA oxidative damage or more effective repair and clearance, but low readings can also result from reduced RNA turnover, hydration status, timing of collection, or analytical factors. Interpretation is most informative when reviewed alongside the Cellular Zoomer’s other markers—DNA oxidation, lipid peroxidation, glutathione turnover, mitochondrial metabolites, microbial byproducts, and antioxidant genetics—to distinguish redox imbalance from changes in nucleic acid turnover or excretion.

The Cellular Zoomer includes 8-Hydroxyguanosine to quantify RNA oxidation as part of a multi-layered redox profile. This marker links oxidative burden to mitochondrial performance, detox capacity, and antioxidant genetics, helping providers identify patterns of cellular stress and tailor further assessment and monitoring.