Fructus Schizandrae (wu wei zi), is commonly used as a tonic in traditional Chinese medicine. Recently, wu wei zi was found to significantly improve liver dysfunction in chronic hepatitis patients.

What is wu wei zi? Fructus Schizandrae is a deciduous woody vine and is dioecious, meaning individual plants are either male or female, thus both male and female plants must be grown. It is very tolerant to shade. Its Chinese name comes from the fact that its berries possess all five basic flavours: salty, sweet, sour, pungent (spicy), and bitter.

Its berries are used in traditional Chinese medicine, where it is considered one of the 50 fundamental herbs. They are most often used in dried form, and boiled to make a tea. Medicinally it is used as a tonic and restorative adaptogen with notable clinically documented liver protecting effects. The primary hepatoprotective (liver protecting) and immuno-modulating constituents are the lignans schizandrin, deoxyschizandrin, gomisins, and pregomisin, which are found in the seeds of the fruit. It should not be used by pregnant women.

During the early 1980's Chinese doctors began researching Schizandra as a treatment for hepatitis, based on its potential for liver-protective effects.

Lignans schizandrins have been found to prevent liver damage, stimulate liver repair, and stimulate normal liver functioning. Schizandrins are claimed to inhibit and even reverse the destruction of liver cells by stimulating the production of cytochrome p-450 which is a protein involved in extramitochondrial electron transport in the liver. In another study, schizandrins have scavenging effects on active oxygen radicals.