Phellodendron (Phellodendron amurense), commonly known as Amur cork tree, has a long history of use in traditional Chinese medicine (TCM). In TCM, it is one of the key herbs in formulas designed to "clear heat" and "dry dampness," which are traditional concepts often applied to conditions involving the bladder and urinary tract, such as urinary tract infections, frequent urination, or inflammation. Specifically, the bark (known as Huang Bai) is used in formulas for what is described as "damp-heat" in the lower burner, which includes the bladder.

The active compounds in Phellodendron, such as berberine, have been shown in laboratory studies to possess antimicrobial and anti-inflammatory properties. These findings provide some plausibility to its traditional use for infections or inflammatory states. However, while there are some studies on berberine and its effects on bacteria commonly implicated in bladder infections, direct clinical evidence for the effectiveness of Phellodendron bark itself in supporting bladder health in humans is limited. Most of the support for its use remains rooted in traditional herbal practice, rather than robust human clinical trials.

In summary, Phellodendron's use for bladder support is primarily justified by traditional herbal medicine, with only preliminary pharmacological evidence and a lack of high-quality clinical trials to fully validate its efficacy for this specific body system.