Key takeaways
- “Functional mushrooms” is a useful description, not a scientific or legal category.
- The most common species are Lion’s Mane, Reishi, Cordyceps, Chaga and Oyster.
- Much mushroom research is laboratory or animal work; human evidence is more limited.
- Whether a product uses fruiting body or grain-grown mycelium makes a real difference.
- Look for the Latin name, the part used, the extraction method and honest language.
Walk into any health shop and you’ll find mushrooms in capsules, powders, coffees and tinctures. The phrase used to describe many of them is functional mushrooms. It sounds precise, but it isn’t a scientific or legal category. It is a useful label for a group of mushrooms people choose for reasons beyond the kitchen.
This guide is a starting point. It covers what the term means, the species you’ll meet most often, what these mushrooms contain, how honestly to read the research, how they are prepared, what separates a well-made product from a poor one, and the common myths worth knowing about.
What are functional mushrooms?
“Functional mushrooms” describes mushrooms that are eaten, brewed or extracted for their naturally occurring compounds rather than purely as food. Some, such as Oyster and Lion’s Mane, are excellent culinary mushrooms too. Others, such as Reishi and Chaga, are too woody or bitter to cook with and have historically been prepared as teas and extracts.
Where the term comes from
The phrase borrows from “functional foods”, a broad and informal idea of foods valued for more than basic nutrition. Several of these mushrooms also have long histories in East Asian and Northern European traditions. Reishi appears throughout Chinese art and literature; Chaga has been brewed as a tea in Siberia and Finland for generations; Cordyceps was prized on the Tibetan Plateau for its rarity. In recent decades, interest from researchers and consumers has grown, and “functional” has become the everyday word for this group.
History tells us how people have valued these mushrooms. It doesn’t, on its own, tell us what they do, which is why we keep tradition and modern evidence clearly separate throughout the Library.
The mushrooms you’ll meet most often
Lion’s Mane (Hericium erinaceus) is recognisable by its cascading white spines. It is eaten in China, Japan and Korea and is one of the most studied functional mushrooms. Read more in The Complete Guide to Lion’s Mane.
Reishi (Ganoderma lucidum) has a kidney-shaped cap with a lacquered red sheen. Too tough to cook, it has been prepared as teas and extracts for over two thousand years. See The Complete Guide to Reishi.
Cordyceps usually refers today to Cordyceps militaris, a bright orange, club-shaped fungus that can be cultivated. It is a relative of the rare Himalayan caterpillar fungus. See The Complete Guide to Cordyceps.
Chaga (Inonotus obliquus) grows on birch as a hard, black, cracked mass rather than a typical mushroom. See The Complete Guide to Chaga.
Oyster (Pleurotus ostreatus) is one of the world’s most widely cultivated culinary mushrooms. See The Complete Guide to Oyster Mushrooms.
You may also come across Turkey Tail, Maitake and Shiitake, among others.
Functional or culinary?
The line is blurry. Oyster and Lion’s Mane are delicious cooked and are also used in extracts. Shiitake is a kitchen staple with a long research history. Reishi and Chaga, on the other hand, are almost never eaten: they are too hard and bitter, so they have always been simmered or extracted. What makes a mushroom “functional” is really how people choose to use it.
What’s inside a mushroom?
Mushrooms are chemically rich. The groups of compounds researchers most often study include:
- Polysaccharides, large carbohydrate molecules found in the fungal cell wall. The best known are beta-glucans.
- Triterpenes, a family of compounds especially associated with Reishi.
- Sterols, such as ergosterol, the fungal counterpart of cholesterol in animals.
- Ergothioneine, an unusual amino acid derivative for which mushrooms are among the richest dietary sources.
- Species-specific compounds, such as hericenones in Lion’s Mane fruiting bodies and cordycepin in Cordyceps militaris.
Which compounds are present, and in what amounts, depends on the species, the part of the fungus used, how it was grown and how it was processed.
What the research does and doesn’t show
There is a large and growing body of research on functional mushrooms, but it varies enormously in quality. Much of it is laboratory research on cells, or research in animals. Human studies exist for some species, but they are often small or short.
Health claims on foods and food supplements are strictly regulated in the UK. That is why responsible brands, including Spore & Bloom, describe what their products are and how they are made rather than what they will do for you. See also In Vitro, Animal and Human Studies: What’s the Difference?
Fruiting body or mycelium?
A mushroom has two main parts: the fruiting body, the visible mushroom, and the mycelium, the network of fine threads it grows from. Many products on the market are made from mycelium grown on grain, which can contain a significant proportion of that grain. It is one of the most important things to understand when choosing a product. Our article Fruiting Body vs Mycelium explains the difference in full.
How functional mushrooms are prepared
The same mushroom can reach you in very different forms:
- Whole dried powder: dried and ground mushroom, unextracted.
- Extract powder: mushroom that has been extracted and then dried, often by spray drying.
- Tinctures: liquid extracts, usually in water and alcohol. See What Is a Mushroom Tincture?
- Capsules: a measured powder, which may be an extract, whole mushroom or mycelium.
- Teas and decoctions: the traditional way of preparing tough mushrooms such as Reishi and Chaga.
Because much of a mushroom’s chemistry is locked inside a tough cell wall, extraction matters. Many producers use both hot water and alcohol, known as dual extraction. For a side-by-side comparison, see Mushroom Tincture vs Capsules vs Powder, and for the process in depth, The Complete Guide to Mushroom Extraction.
How to choose a mushroom product
A few questions will tell you most of what you need to know:
- Does it name the species? Look for the Latin name, not just “mushroom complex”.
- Which part of the mushroom is used? Fruiting body, mycelium, or both?
- How was it extracted? Hot water, alcohol, both, or not at all?
- Where does the mushroom come from? Good brands are open about origin.
- What else is in it? Check for fillers, carriers and flavourings.
- Is the language honest? Be wary of products promising specific health outcomes.
Our guide to choosing a mushroom extract goes into each of these in more detail.
Common myths
- “Natural means it can’t do any harm.” Natural products can still interact with medication or disagree with some people. Follow the label and seek advice if unsure.
- “More is better.” There’s no reason to exceed the amount on the label.
- “Mycelium and fruiting body are the same thing.” They are different parts of the fungus, and mycelium products may contain a lot of grain.
- “‘Full spectrum’ means better.” It isn’t a defined term. Ask what it actually means for that product.
- “Centuries of use prove it works.” Tradition and evidence are different things, and both are worth understanding on their own terms.
- “Functional mushrooms are psychedelic.” The species in this guide contain no psychoactive compounds.
A short glossary
- Fruiting body: the visible mushroom, which releases spores.
- Mycelium: the network of fine threads a fungus grows as; each thread is a hypha.
- Substrate: the material a fungus grows on, such as wood, sawdust or grain.
- Beta-glucans: glucose-based polysaccharides in the fungal cell wall.
- Triterpenes: a family of compounds, often bitter, that dissolve better in alcohol than water.
- Dual extract: an extract made with both hot water and alcohol.
- Extract ratio: how much mushroom went in compared with how much extract came out. See Understanding Mushroom Extract Ratios.
Getting started
If you decide to try a mushroom product, follow the directions on the label and don’t exceed the suggested amount. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak to a healthcare professional first. Our tinctures are intended for adults.
Questions people ask
Are functional mushrooms the same as magic mushrooms?
No. The mushrooms in this guide, such as Lion’s Mane, Reishi, Cordyceps, Chaga and Oyster, contain no psychoactive compounds.
Which functional mushroom should I start with?
There’s no single answer. Many people start with whichever species interests them most, whether for its history, its character or simple curiosity. Our species guides above are a good place to begin.
Can I take more than one?
Many people do. Follow the suggested amount for each product.
Are functional mushrooms regulated?
In the UK, most are sold as food supplements and must meet food law, including strict rules on health claims. No health claims are currently authorised for these mushrooms.
How we approach functional mushrooms
At Spore & Bloom we make small-batch tinctures in Dorset from UK-grown fruiting bodies, and from wild chaga harvested from birch in Finland. Each is extracted in hot water, with the help of ultrasonic extraction, and in plant-derived ethanol. You can explore the range in our mushroom tinctures collection, or keep reading in the Library.