Porcini

Safety first. If anyone has eaten a wild mushroom and you are worried, call Poison Help at 1-800-222-1222 (US) right away and do not wait for symptoms; call 911 for collapse, a seizure, or severe vomiting with confusion. See Plant and Mushroom Poisoning. This page does not help anyone identify or gather mushrooms.

What porcini is

Porcini, also called cep or penny bun, is Boletus edulis Bull., an accepted species in the family Boletaceae. [1] It is eaten as a food, fresh or dried. A narrative review describes it as nutritious and delicious, rich in carbohydrates, proteins, minerals and taste compounds, and low in fat and calories. [2] Treat this as a general food description. We did not read a nutrient table for porcini this session, so there are no numbers here; see Mushroom Nutrition for values we did verify for other mushrooms.

Traditional use

The sources we read for this page do not describe a traditional medicinal use of Boletus edulis in any named region or period. Proper evidence not found for traditional use; we read one narrative review and searched PubMed for porcini. Porcini is best understood as a culinary mushroom.

What research shows

A result for an extract or isolated compound does not transfer to a plate of cooked mushrooms, and the reverse is also true.

Metals in mushrooms

Mushrooms can take up metals from where they grow. In a 2026 study of 164 commercial dried mushroom samples on the Polish market, Boletus edulis showed the highest accumulation of cadmium among the six species analyzed; median levels across most species stayed within the study's safety thresholds, but there was high variability between producers and some outliers. [4] A 2024 Romanian study of wild edible mushrooms, including B. edulis, reported nickel accumulation by B. edulis relative to the soil, and found daily intake of toxic metals from these mushrooms to be higher for children than for adults (1.5 times). [5]

These are measurements in specific samples. They are not a statement about every package. Where mushrooms come from and how they are certified can matter: the Polish study found certified organic samples had lower mercury and arsenic. [4] For a general quality guide see Quality Testing and Certifications.

Lab data and chemistry

This section is about what laboratories have measured in porcini. It is separate from the safety advice above and does not show that eating porcini improves any health condition. Wikidata (the open knowledge base behind the LOTUS natural-products project) lists only 5 compounds reported in Boletus edulis, all small aromatic compounds, and none of those statements points to a paper we could open. [8] A listing means "reported in at least one study of this species", not "present in every product". [8] Most of the useful numbers below therefore come from review and survey papers, not from a compound database.

A. What the laboratory literature reports in this mushroom

The narrative review is the only source we read for the polysaccharide, phenolic and phytosterol groups, and we read its abstract only; it lists activities seen in cells and animals, not in people. [2]

B. Measured values

USDA FoodData Central, the main source of nutrient tables on this site, has no porcini or Boletus edulis entry in the files we hold, so there are no USDA values for porcini. [8] The numbers below come from papers on wild mushrooms; all are per kilogram of dry matter unless stated.

The caesium rows show how wide the range is. European samples from 1995 to 2010 were two to four orders of magnitude higher than the Yunnan samples. [10] The Polish study of different ages found the youngest button-stage fruiting bodies about fourteen times higher in caesium-137 than older ones. [12] No open measured value found here for fresh versus dried ergothioneine in porcini, for total polysaccharides or beta-glucan, for vitamin D2, or for any supplement product.

Fresh versus dried. Fresh mushrooms are mostly water, so a "per kilogram dry matter" figure is about ten times a "per kilogram fresh" figure; the Polish caesium study shows 36 against 360 for the same sample. [12] Dried porcini are therefore concentrated, and a dried packet gives more of everything per gram, including cadmium and caesium, which is one reason the Polish market study tested dried products. [4] [12] Soaking and cooking juice carries some caesium out: in one cooking study, removing the juice took out part of the radiocaesium, and boletes held less caesium in their juice than chanterelles did. [13] Another study found braising raised the caesium figure per gram of fresh weight, because water was lost, so figures need to be read with their basis. [12]

Look-alikes. Wild porcini are collected by people who know them well, and the species has bitter relatives. The Missouri Department of Conservation lists the bitter bolete (Tylopilus felleus) as not edible, extremely bitter, and a look-alike of the king bolete. [15] Do not identify wild fungi from text or an app; ask a local expert, and use Poison Help (1-800-222-1222, US) if anything has been eaten by mistake. [7]

C. What the numbers do and do not mean

• Ranges are wide. Cadmium in porcini caps spans more than two orders of magnitude, and caesium depends mostly on where the mushroom grew and how old it was. [9] [10] [12] Treat each number as one measurement, not a fixed property of "porcini".


• A compound found in the lab, or active in cells and animals, is not shown to do anything in people who eat porcini. [2]


• Ergothioneine is a food nutrient of interest, but whether extra ergothioneine from a supplement helps people is unproven. The "more than 7 mg per g" figure is dry weight and a portion of fresh mushroom contains much less. [14]


• These are wild-collected values. Cultivated or farmed mushrooms can differ, and a capsule or extract is a different product from a plate of cooked mushrooms; see food portions vs supplement amounts.


• A heavy-metal or caesium figure is a measurement of a sample, not a ruling that all porcini are unsafe; see Mushroom Heavy Metals and Contamination and Fresh vs Dried Mushrooms.