Key takeaways
- Reishi is a glossy, woody bracket fungus traditionally prepared as teas and extracts.
- “Reishi” covers several Ganoderma species; naming in the trade is often imprecise.
- Its best-known compounds are triterpenes (alcohol-soluble) and polysaccharides (water-soluble).
- That chemistry makes Reishi a clear case for dual extraction.
- Its long history is cultural context, not evidence of effect.
Few mushrooms carry as much history as Reishi. With its kidney-shaped cap and deep red, lacquered sheen, it has appeared in Chinese art and literature for around two thousand years. Too tough and bitter to cook with, it has always been prepared as teas and extracts. This guide covers what Reishi is, how to recognise it, how it grows and is cultivated, the confusion around its name, what it contains, what the research does and doesn’t show, and how to choose a Reishi product.
At a glance
- Scientific name: usually given as Ganoderma lucidum (see the note on naming below)
- Other names: lingzhi (China), reishi (Japan), varnished conk
- Grows on: hardwood trees and stumps
- Texture and taste: hard, woody and strongly bitter
- Part used: the fruiting body, or in some products the mycelium or spores
What it looks like
Reishi is a bracket fungus. Its fan- or kidney-shaped cap has a glossy, varnished surface that ranges from deep red to orange-brown, often with a paler growing edge. It is hard and woody rather than soft, with fine pores rather than gills on the underside. The stem, when present, is often set to one side and shares the same lacquered shine.
Unlike soft mushrooms that last a few days, a Reishi fruiting body can persist for months, slowly growing and hardening.
Similar species
Ganoderma is a large genus, and several species grow in Britain. The artist’s bracket (Ganoderma applanatum) is common on beech but has a dull, crusty upper surface rather than a glossy one; its white underside darkens when scratched, which is how it earned its name. Other glossy species can be hard to tell apart without expert help. See Artist’s Bracket: The Fungus You Can Draw On.
A note on names
“Reishi” and “lingzhi” have been applied to several closely related Ganoderma species. Research has shown that much of the cultivated Asian material long sold as Ganoderma lucidum is a distinct species, often now called Ganoderma lingzhi. Our article Ganoderma Species Explained untangles this.
This matters when reading research, because studies labelled with the same name may not have used the same fungus.
Two thousand years of history
This history explains why Reishi is so widely known. It isn’t, however, evidence of what Reishi does. Read Reishi Through History and Traditional Culture for the full story.
How it is cultivated
Reishi grows slowly. Commercially, it is cultivated on hardwood logs or on sawdust-based substrates, and the fruiting bodies are harvested once mature, then dried. Because they are so woody, they are almost always sliced or ground before extraction.
Growing conditions shape the fruiting body. With plenty of fresh air, Reishi forms its familiar kidney-shaped cap; in still air with high carbon dioxide, it grows long, branching “antler” forms instead. Both are the same fungus.
Why Reishi isn’t cooked
Reishi is too hard to chew and intensely bitter, largely because of its triterpenes. That’s why, for centuries, it has been sliced thin and simmered for a long time into a dark, bitter tea, and why today it is mostly used in extracts. See How Reishi Is Extracted.
What’s inside Reishi?
Two groups of compounds receive most attention:
- Triterpenes, including the ganoderic acids, which give Reishi much of its bitterness. See Triterpenes in Mushrooms Explained.
- Polysaccharides, including beta-glucans, found in the cell wall.
These two groups behave very differently during extraction. Polysaccharides dissolve in hot water, while triterpenes dissolve much better in alcohol, which is why Reishi is one of the clearest cases for dual extraction. Read Reishi Compounds Explained for more.
Spores and spore oil
You may also see products made from Reishi spores, sometimes described as “cracked” or “broken-wall” spores, or from oil pressed from them. These are a different material from the fruiting body, with a different make-up, and they are made in a different way. If you come across them, check the label carefully for exactly what the product contains.
What does the research say?
Our article Reishi Research: How to Read the Evidence explains how to approach it.
Common myths
- “Reishi is one species.” The name has covered several closely related species, and much of what is sold as G. lucidum is G. lingzhi.
- “The more bitter, the better.” Bitterness reflects triterpene content, but it isn’t a reliable guide to quality on its own.
- “Two thousand years of use proves it works.” Tradition tells us how people valued Reishi; it isn’t evidence of effect.
- “A hot water extract captures everything.” Water leaves most triterpenes behind; alcohol is needed to reach them.
How to choose a Reishi product
- Look for the species named on the label.
- Check the part used: fruiting body, mycelium or spores.
- Prefer a product that uses both hot water and alcohol extraction, given Reishi’s chemistry.
- Check the full ingredients for fillers or carriers.
- Be wary of claims about specific effects.
See How to Choose a Reishi Extract and Reishi Tincture vs Powder.
Questions people ask
Why is Reishi so bitter?
Mostly because of its triterpenes, including the ganoderic acids. Bitterness is simply part of Reishi’s character, and many people take a tincture in a drink to soften it.
Is Reishi the same as lingzhi?
Yes. Lingzhi is the Chinese name and reishi the Japanese name for the same group of glossy Ganoderma fungi.
Can I cook with Reishi?
Not in the usual sense. It is far too hard and bitter to eat, which is why it is traditionally simmered as a tea or extracted.
Can I find Reishi in Britain?
Glossy Ganoderma species do grow here, but they are easily confused with one another, and wild bracket fungi play an important role in woodland. There’s no need to collect them: cultivated Reishi is widely available.
Is Reishi safe?
Follow the label and don’t exceed the stated amount. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak to a healthcare professional before use.
How we make our Reishi tincture
Our Reishi tincture is made from UK-grown Reishi fruiting bodies, extracted in hot water using ultrasonic extraction and in plant-derived ethanol, then combined and prepared in small batches in Dorset, with nothing else added. Many people like to make it part of their evening routine.