Synopsis

Phellodendron amurense, commonly known as Amur cork tree, is a deciduous tree native to northeast Asia, especially China, Korea, and Japan. In traditional medicine, its thick, corky bark—known as Huang Bai in Traditional Chinese Medicine (TCM)—is highly valued for its anti-inflammatory, antibacterial, antiviral, and detoxifying properties. The bark contains potent alkaloids such as berberine, palmatine, and jatrorrhizine, which are responsible for its broad pharmacological actions.

Phellodendron bark is best known for its use in clearing heat and dampness—terms in TCM that often correspond to modern concepts like infection, inflammation, and fluid retention. It is used to treat conditions such as urinary tract infections, damp-heat diarrhea, dysentery, jaundice, and skin diseases like eczema, boils, and acne. It also supports liver health, lowers fevers, and may reduce symptoms of arthritis and joint inflammation.

Modern research confirms that berberine-rich Phellodendron bark has antimicrobial properties effective against a range of pathogens, as well as blood sugar-lowering, lipid-regulating, and insulin-sensitizing effects. It also shows promise in modulating the gut microbiota, supporting metabolic function, and even providing anti-cancer activity in early studies.

Phellodendron is often used in combination with Coptis chinensis (Huang Lian) and Scutellaria baicalensis (Huang Qin) in TCM formulas to address more intense or systemic “toxic heat” or inflammation. In Western integrative medicine, it is sometimes included in supplements for weight loss, stress reduction (as a cortisol modulator), and prostate health.

Historical Use in Medicine
In Traditional Chinese Medicine, Phellodendron bark has been used for over 2,000 years, documented in the Shennong Bencao Jing, one of China’s earliest pharmacopeias. It is one of the “Three Yellows”—a group of strongly bitter, yellow-colored herbs used to clear internal heat and dampness. Huang Bai is traditionally used to treat damp-heat in the lower jiao, making it a staple remedy for bladder infections, leukorrhea, burning urination, and lower body inflammation.

In Kampo medicine (traditional Japanese medicine), Obaku (Phellodendron bark) is used in similar ways to detoxify the system and treat skin eruptions, diarrhea, and liver heat. It was sometimes included in purgative or antipyretic formulas.

Despite its strong bitterness, Huang Bai has remained a mainstay herb in TCM due to its ability to cool excess fire, drain dampness, and relieve toxic conditions internally and externally.

Other names

Amur Cork Tree
Huang Bai
Yellow Bark