Journal

Functional mushrooms: lion’s mane, reishi, chaga, cordyceps and shiitake

“Functional mushrooms” is a retail term, not a scientific group. Five of the most talked about mushrooms: what they are, where they grow and how people use them.

October 27, 2026 6 min read

Close up of lion’s mane spines in an autumn forest

Shops increasingly use the label “functional mushrooms”. It is a retail term, not a scientific group: it covers mushrooms that are sold more often as powders, extracts or capsules than as ordinary food. EU law has no such category: these products are either foods or food supplements. Below is a short guide to the five mushrooms you will see most often: what they are, what they look like, where they grow and how people use them. They are very different: some are eaten like any other mushroom, some are brewed into drinks and some you will hardly ever see in the wild.

Lion’s mane (Hericium erinaceus)

Lion’s mane, ežinis trapiadyglis in Lithuanian botany, is a white mushroom with no cap, just soft hanging spines. It grows on old broadleaf trees, in Europe mostly beech and oak. Like shiitake, it can be cooked like any other mushroom: pan fried, it tastes a little like crab.

Wild lion’s mane is rare in Europe, and in some countries picking it is against the law. In Lithuania its relative, the coral tooth fungus, is in the Red Data Book and may not be picked. So do not pick wild Hericium. The lion’s mane on sale is farmed, and in Lithuania you can buy it fresh or dried from mushroom growers. More in What is lion’s mane and How to cook lion’s mane.

Reishi (Ganoderma)

Reishi (lingzhi in Chinese) is a tough bracket fungus. Its cap is reddish brown, kidney shaped and glossy, as if varnished, with the stem attached at the side. In the wild it grows at the base of broadleaf trees and on stumps. It is too hard and bitter to eat, so it is traditionally sliced thin and simmered in water for a long time.

Scientists are still debating which species is the true reishi. The mushroom farmed in Asia is often sold as Ganoderma lucidum, but it differs genetically from the European species, and newer work calls it Ganoderma sichuanense. The European Ganoderma lucidum is listed in the Lithuanian Red Data Book, so it must not be picked. Reishi on sale is grown on sawdust or logs, mostly in Asia, and sold as dried slices, powder, extracts or capsules.

Chaga (Inonotus obliquus)

Chaga, also known as cinder conk, is not actually a fruiting body. It is a hard, black, cracked mass of mycelium (a sclerotium) that grows on living birch trunks and less often on other broadleaf trees. Its black colour comes from the pigment melanin. The fungus forms its real fruiting bodies under the bark only after the tree dies, so they are seldom seen.

Chaga grows in birch forests across the northern hemisphere. It is traditionally grated into a fine powder and brewed into a drink that resembles coffee or tea. It is sold in chunks, cut for tea or as extract powder. The fungus can live in a tree for decades and chaga is cut from living trees, so it is worth choosing chaga from responsibly managed forests.

Cordyceps (Cordyceps militaris)

Cordyceps are fungi that grow on insects in the wild. The species sold most often, Cordyceps militaris, has bright orange, club shaped fruiting bodies 1 to 8 cm tall that grow out of insect pupae buried in the soil. It occurs across the northern hemisphere, and in Europe it fruits from August to November.

The cordyceps on sale is grown without wild insects, on rice or in a liquid nutrient medium, mostly in China and Vietnam. In Asia the fruiting bodies are cooked in chicken or pork broth and added to other hot dishes. It should not be confused with Ophiocordyceps sinensis, a wild fungus from the Tibetan Plateau and the Himalayas, collected by hand at 3,000 to 5,000 m and one of the most expensive fungi in the world.

Shiitake (Lentinula edodes)

Shiitake is an everyday edible mushroom with a brown cap, native to East Asia and now grown around the world on hardwood logs or sawdust blocks. It has a strong, savoury taste and works in stews, soups or a hot pan. Dried shiitake is soaked before cooking, and the soaking water makes a good stock. Several farms grow shiitake in Lithuania, so fresh ones turn up in shops too. Shiitake is mostly eaten as food, although it is also sold as powder or extract.

How to compare mushroom supplements

Whatever the mushroom, the questions are the same: which part of the fungus is used, whether it is an extract or ground powder, what was measured and whether the label is complete. We cover them in Fruiting body or mycelium and How to read a food supplement label. In blends that contain several mushrooms, the amount of each should be stated separately.

It is also worth knowing that the EU Register lists no authorised health claim that applies to these mushrooms. So when comparing products, the most useful things to look at are the ingredients, the origin and the label.

In short

“Functional mushrooms” is a retail term, not a scientific group or a legal category.
Lion’s mane and shiitake are eaten as food, reishi and chaga are traditionally brewed into drinks, and cordyceps goes into soups in Asia.
In Lithuania the coral tooth fungus and Ganoderma lucidum are Red Data Book species, so do not pick wild Hericium or reishi.
The lion’s mane, reishi and cordyceps on sale are mostly farmed.

Cerebro capsules contain lion’s mane extract. The ingredients and full label are on the product page. Choose your set