Phellodendron bark, derived from the Phellodendron amurense tree, has a long history of use in Traditional Chinese Medicine (TCM), where it is known as "Huang Bai." It is most commonly used for its purported anti-inflammatory, antimicrobial, and detoxifying properties, and is not a primary herb for stress or anxiety in the classical Chinese materia medica. However, some modern traditional formulations, particularly in combination with Magnolia bark (as in the proprietary blend Relora®), have been marketed for stress reduction and mood support. The traditional rationale for its inclusion in such blends is more supportive than central, often aiming to balance the body's internal environment ("clearing heat" and "draining dampness") rather than directly targeting psychological stress.

Scientific studies specifically investigating Phellodendron bark alone for stress reduction are extremely limited. Most available research on stress relief involves blended extracts (notably Relora®, which combines Phellodendron and Magnolia) and suggests possible reductions in stress and cortisol levels. However, it is unclear whether Phellodendron alone is responsible for these effects, since Magnolia bark is itself noted for its anxiolytic properties. Thus, while traditional use may support its inclusion in some stress-targeted formulas, scientific validation for Phellodendron bark as a stand-alone treatment for stress is lacking.