What is Reishi?

Common names

Reishi mushrooms have many common names. In addition to reishi, two of their most popular names are the scientific name, Ganoderma lucidum, and the more accurate name for red reishi, Ganoderma lingzhi or simply ling zhi. Reishi mushrooms are also known as “red reishi” or “red mushroom” in Asian countries, although there is a black variety called Ganoderma sinese that is often used as reishi.

Anatomy of a mushroom

When mushrooms are discussed, the words “fruiting body” and “mycelium” often come up, so it’s important to understand what parts of the mushroom these refer to. The fruiting body is the part of the mushroom that’s above ground. It’s what most people think of when picturing a mushroom. In the case of reishi there is a stem (like the trunk) and a cap (the top). Mycelium is the thread-like structure underground, like the roots of the mushroom.


Reishi has been used as a medicinal mushroom in China, Japan, and other Asian countries for over 2000 years. It is a polypore fungus that grows on the trunks of living or dead trees and logs. The fruiting body is kidney-shaped with a wavy undersurface. The button-stage (young) fruiting bodies are deep red to orangish red. In mature fruiting bodies, the colour changes to brownish orange or golden yellow.

Reishi grows throughout the world in temperate forests and mountainous regions and can live for many years. When the mushroom reaches maturity, it exudes a varnish-like substance from its pores, which causes it to have a glossy appearance on its surface.

Reishi is the Japanese name most commonly used for the mushrooms Ganoderma lingzhi, Ganoderma lucidum, and Ganoderma sinense, though there are many species within the Ganoderma lineage. The word “Ganoderma” refers to the mushroom’s shiny skin. The most common types of Ganoderma are:

  • Ganoderma lingzhi (red reishi)
  • Ganoderma lucidum (often used interchangeably with lingzhi)
  • Ganoderma sinense (black reishi)
  • Ganoderma tsugae (Hemlock varnish shelf)
  • Ganoderma amboinense (deer antler)
  • Ganoderma applanatum (artist’s conk)

What’s the “real” reishi? Reishi as ling zhi

Traditional Chinese Medicine (TCM) and other traditional forms of medicine from Asia have used Ganoderma lingzhi (red reishi) for thousands of years.

In fact, ling zhi has been documented in Chinese medicine’s pharmacopoeia since about the 200 B.C. The origin of its name, ling zhi, can be translated as “herb of spiritual potency,” “mushroom of immortality,” or “holy herb,” symbolizing its high value it was assigned.

The species Ganoderma lingzhi grows wild in east Asia but is rare, so it is now largely cultivated. Because of taxonomic confusion, Ganoderma lucidum—the European version—is commonly named interchangeably with Ganoderma lingzhi, but they are not the same. Because much of modern research and the supplement industry calls reishi “G.lucidum” and that has become the most recognized name, there remains great confusion.

An example of how companies use the name G.lucidum more broadly, and sometimes inaccurately, is described in this phytochemical study that also identified that G.lingzhi contains more of the bioactive, medicinal triterpenes than G.lucidum.

* For the purpose of this website, most of the information provided here refers to “red reishi” or ling zhi, which is Ganoderma lingzhi.

Because of a growing interest in the medicinal value of red reishi, research on reishi mushroom is expanding and we are learning more about the health benefits as well as the specific compounds and their actions. In particular, reishi mushrooms contain a high concentration of polysaccharides and triterpenes (such as ganoderic acid).

Red reishi is most commonly recognized for its ability to support the immune system and to calm the nervous system, but it offers an array of other health benefits as well.

Main Bioactive Components of Reishi

Reishi mushrooms have been found to contain an array of bioactive compounds and new ones are added as they are discovered. Interestingly, while most mushrooms are made up of about 90% water, fresh reishi mushroom’s water content is much lower, at 75%, meaning it is denser in other compounds. The main bioactive ones currently under study fall under the headings of polysaccharides and triterpenes.

The main bioactive ones currently under study fall under the headings of polysaccharides and triterpenes.

Polysaccharides are carbohydrates made up of long chains of monosaccharides, which are a simple sugars like glucose, fructose, and ribose. While we often hear “sugar” and “carbohydrates” in a negative way, they are essential components of nature and nutrition. Polysaccharides store energy, provide structural support, and have medicinal benefits. While most foods contain polysaccharides, the type of polysaccharide determines its medicinal value. So, when a product includes the amount of polysaccharides, it may include polysaccharides from the medium in which it is grown (e.g. rice, especially for mycelium products) or added to the final product (e.g. starch or dextran).

One of the most researched polysaccharides in reishi mushroom is the beta-D-glucans, found to have immunomodulating, immune-stimulating, and anti-tumour effects.

Triterpenes are precursors to steroids in plants and animals. While more than 140 triterpenes have been found in reishi mushroom, ganoderic acids are unique to this amazing fungi. Triterpenes are very bitter in flavour and have been studied for their broad range of health benefits, including for liver, heart, kidneys, and immune system.

Ling Zhi-8 (LZ-8) protein is a protein from Ganoderma lucidum that has immunomodulatory function.

History of Reishi

Reserved for Royalty

Reishi’s reputation for treating a wide range of ailments caused Chinese emperors throughout the various dynasties to order their servants to search for wild red reishi mushrooms found atop distant mountains. They believed that the consumption of ling zhi would grant them eternal youth and enhanced health. Because of the mushroom’s remote habitat and the scarcity of high-quality specimens, the use of red reishi for medicinal purposes was reserved primarily for royalty and aristocrats.

It was not until the late 20th century, that this once-rare plant, through diligent cultivation by the Japanese, was it made widely available to the general public.

Part of Asian culture

Over the ages, red reishi has become ingrained in Oriental art and culture because of its prestigious status in Traditional Chinese Medicine (TCM). Since the first Chinese dynasty, paintings, embroideries, buildings, and sculptures of the gods and immortals have depicted reishi as a symbol of divinity, longevity, and good fortune.

Depictions of reishi are displayed throughout the Forbidden City and the Summer Palace in Beijing as a testimony to its value, and the mushroom’s distinctive shape was a favourite ornamental design feature used by royalty and the wealthy. Even the traditional scepter of the emperors of China was a stylized reishi, called a “Ru Yi.”

Reishi was further immortalized as the ultimate healing substance and spiritual herb of China in the classic Chinese fairytale “The White Snake.” In this story, a mystical snake who has taken the form of a human steals a magical reishi plant from the gods to save the life of her human lover. The celestial battle for the reishi rivals the battles portrayed in Homer’s Iliad and is one of China’s famous “Four Classic Folktales.”