Fruiting body

In mushroom science, "mushroom" refers to fungi that produce large fruiting bodies visible to the naked eye, and the word covers both the mycelial network and the fruiting body itself [3]. Fruiting bodies of various mushrooms have been eaten as major food crops [3].

In shiitake, a fruiting body forms only after the mycelium has grown. During cultivation, mycelia first colonize a synthetic log of sawdust substrate, and after physiological and environmental triggers they change their metabolism [2]. After a period of growth and specific environmental cues, knots of hyphae form, then aggregate and differentiate, the stem elongates, spores are produced and the cap expands to form a mature fruiting body [2]. The fruiting body usually grows exposed outside the medium, while the vegetative mycelium stays mostly underground [1].

Fruiting body and mycelium are not chemically the same. A 2026 review of food-safety-relevant basidiomycete mushroom toxins, with a particular focus on Pleurotus species, found that some toxins detected in fruiting bodies were absent in mycelium [1], and it reports the general legislative standpoint that mycelium safety should not be assumed from fruiting bodies [1]. Regulators can also handle the parts differently: the European Commission's novel food consultation list records a 2026 decision that a Hericium erinaceus powder extract from the fruiting body is not novel, and a 2019 decision that the dehydrated mycelium powder is a novel food [4].

So the part named in a study's methods matters. A trial of a fruiting body extract tells you about that extract, and a product made mostly from mycelium is a different material. Look for the part used, the extraction method and any compounds the extract was standardized to.

For the graded evidence, see Lion's mane.

• Mycelium
• Novel food
• Standardized extract