Cat's Whiskers (Java Tea) for Kidney Health

Research suggests that Cat's Whiskers (Orthosiphon aristatus, also known as Java Tea) has been investigated primarily in preclinical settings for its potential role in kidney health, with the bulk of available evidence coming from animal studies, in vitro experiments, and mechanistic investigations rather than human clinical trials. Studies indicate that plant extracts and isolated compounds, including total flavonoids and rosmarinic acid, may help prevent calcium oxalate crystal deposition, dissolve existing urinary stones, and exert diuretic and uricosuric effects that could be relevant to kidney stone prevention, with one 2025 study pointing to the EGFR/PI3K/AKT signaling pathway as a possible mechanism. A 2012 review and several individual studies consistently support renal protective and diuretic properties, and a 2008 study additionally noted hypouricemic effects potentially relevant to uric acid stone formation. Findings are largely supportive in direction, though one 2017 study produced mixed results regarding protection against drug-induced kidney damage depending on extract type, and the overall body of evidence remains limited by the absence of robust human clinical trials, meaning conclusions about efficacy in people cannot yet be firmly drawn.