Phellodendron, known in traditional Chinese medicine as Huang Bai, has been used for centuries as an herbal remedy. Its bark is commonly included in formulas intended to support urinary tract health, including issues involving the bladder. In traditional systems, Phellodendron is believed to possess “damp heat” clearing properties—meaning it is thought to help alleviate symptoms such as urinary discomfort, frequency, or burning, which are attributed to excess heat or dampness in the bladder according to traditional diagnostic frameworks. Modern scientific validation of Phellodendron’s effects on the bladder specifically is limited. Some laboratory studies have identified berberine and other alkaloids within Phellodendron, which show antimicrobial and anti-inflammatory activities. These properties could, in theory, be beneficial for bladder health, especially in the context of infections or inflammation. However, there are few, if any, robust clinical trials directly evaluating Phellodendron’s efficacy for bladder conditions in humans. In summary, the use of Phellodendron to support bladder health is justified primarily by traditional use and historical precedent, rather than strong contemporary scientific evidence. While its phytochemical constituents have shown relevant biological activities in vitro or in animal studies, clinical evidence in human populations is sparse. Thus, its rating for evidence supporting bladder health is moderate to low, pending further research.