Phellodendron (commonly derived from Phellodendron amurense, or Amur cork tree) is traditionally used in Chinese herbal medicine, where it is known as "Huang Bai." In Traditional Chinese Medicine (TCM), Huang Bai is recognized for its “clearing damp-heat” properties and is commonly prescribed as part of formulas intended to support healthy kidney and urinary function, especially in cases of what TCM describes as "damp-heat in the lower burner" (which includes the kidney and bladder region). It is often combined with other herbs such as Coptis (Huang Lian) and Gardenia (Zhi Zi) in classic prescriptions like "San Huang Xie Xin Tang."

The traditional rationale is not based on Western biomedical understanding of kidney physiology, but rather on TCM theory, which encompasses broader concepts of organ system balance and patterns of disharmony. There is limited direct scientific evidence linking Phellodendron or its constituents (such as berberine) to specific protective or restorative effects on the kidneys in humans. Some preclinical studies suggest that berberine may have anti-inflammatory and antioxidant properties, which could theoretically benefit kidney health, but these findings are preliminary and not specific to Phellodendron or to clinical kidney support.

In summary, while Phellodendron is widely used in TCM traditions to "support the kidney system," this use is primarily based on historical and traditional practices rather than robust scientific validation.