Shiitake: Nutrition, Dried Shiitake and Why to Cook Them Well

Shiitake are the brown, umbrella-shaped mushrooms with a savory, almost smoky flavor that turn up in miso soup, stir-fries and ramen bowls. They are sold fresh and dried, and the dried caps are a pantry staple in East Asian cooking. This guide uses USDA SR Legacy data to show what raw, cooked and dried shiitake provide, explains a skin rash linked to raw or undercooked shiitake in peer-reviewed reports, and answers a common question: are shiitake mushrooms healthy?

Peptide Labs does not sell shiitake or shiitake products; this guide is about the food. This article is general nutrition and cooking information, not medical advice.

What are shiitake mushrooms?

Shiitake mushrooms are the fruiting bodies of Lentinula edodes, a fungus that grows on wood. A 2025 review of shiitake cultivation notes that the cultivars grown in the main production areas trace back to wild strains from northern Asia, and that most shiitake are now produced on synthetic logs filled with a sawdust substrate. A 2021 study adds that traditional cultivation on natural logs has largely been replaced by sawdust. So the shiitake in a supermarket are farmed, not gathered.

In the kitchen, shiitake have tan to dark brown caps, firm, meaty flesh and tough, woody stems, so they hold their shape in soups and braises. Our portobello guide covers a mushroom of a different species, Agaricus bisporus, and our general mushrooms guide compares common types side by side.

Shiitake nutrition: raw, cooked and dried

USDA SR Legacy lists separate entries for raw, cooked and dried shiitake. The table uses USDA’s own portions where they exist: 100 grams of raw shiitake (USDA’s only raw portion is one whole mushroom), four cooked shiitake (72 grams) and four dried shiitake (15 grams). %DV uses FDA Daily Values.

Three patterns stand out in the USDA data. First, shiitake are low in calories: one whole raw mushroom (19 grams, USDA’s portion) lists about 6 calories. Second, the standout nutrients are copper and pantothenic acid, with selenium and B vitamins in smaller shares; our guides to copper in foods and selenium in foods put those numbers in context. Third, the raw, cooked and dried entries are separate USDA analyses, so they do not convert neatly into one another; the cooked entry, for example, lists more copper but less potassium per 100 grams than the raw one. Read each column as its own reference value.

Vitamin D is low in all three entries. NIH’s Office of Dietary Supplements (ODS) says mushrooms provide variable amounts of vitamin D2 and that some mushrooms on the market are exposed to UV light to raise it, so check the label of any package that makes a vitamin D statement. Our vitamin D foods guide lists the USDA and ODS values for other sources, and the portobello guide shows USDA’s UV-exposed entries.

Dried shiitake: concentrated flavor and nutrients

Drying removes most of the water, which concentrates everything else. Per 100 grams, USDA lists 296 calories and 11.5 grams of fiber for dried shiitake, against 34 calories and 2.5 grams for raw. Four dried caps weigh about 15 grams, and that USDA portion is what the table shows.

• Soaking: cover dried shiitake with warm water until soft and pliable, then squeeze them gently. Thick caps take longer than thin ones.
• Soaking liquid: the brown liquid is full of flavor; strain it to remove grit and add it to soups, sauces or rice.
• Stems: rehydrated stems stay tough, so most cooks trim them off and simmer them in stock instead.
• Cooking: rehydrated shiitake still need to be cooked through in the dish, the same as fresh ones.
• Storage: keep dried shiitake in an airtight container in a cool, dry cupboard.

Dried shiitake are a classic base for broths, alongside miso and soy sauce. Those seasonings, not the mushrooms, carry most of the sodium in a bowl of soup or ramen; our lower-sodium foods guide explains how to read those labels.

Shiitake dermatitis: why undercooked shiitake can cause a rash

Shiitake dermatitis is an unusual, very itchy rash made of red, raised lines that look like whip marks, often across the trunk, arms and legs. Doctors call the pattern flagellate dermatitis. A 2017 systematic review of 50 published patients found that most cases followed raw shiitake and 22% followed lightly cooked or undercooked shiitake. The linear rash was present in 98% of patients and itching in 78%. The review describes lentinan, a polysaccharide in the cell walls of shiitake, as the suspected trigger, and reports that the rash cleared on its own in about 12.5 days on average.

A 2022 study of French poison control center records counted 59 cases of shiitake dermatitis between 2014 and 2019. Every case followed raw or undercooked shiitake, for example mushrooms only briefly tossed in a wok, added to soup or baked on pizza. The rash appeared anywhere from 1 to 168 hours after eating, with a median of 48 hours, and every patient recovered. The authors note that lentinan breaks down with heat and that inadequate cooking clearly seems to drive the problem. A 2026 case report adds that people who react should avoid shiitake afterward, since severe reactions after repeated contact have been described, and another 2026 report linked the rash to a mushroom coffee drink, which its authors called a new exposure route.

The practical message is simple: cook shiitake until they are soft and cooked through, not seared on the outside and raw in the middle, and skip raw shiitake in salads. If a streaky, itchy rash appears a day or two after a shiitake meal, tell a doctor or dermatologist about the mushrooms so they can recognize the pattern. Swelling of the lips or throat or trouble breathing after any food needs urgent care.

Are shiitake mushrooms healthy?

As a food, shiitake fit a varied diet the way other vegetables do. USDA data show they are low in calories and sodium and supply copper, pantothenic acid and some selenium, fiber and B vitamins. They are not a meaningful protein source compared with the foods in our protein foods guide.

Shiitake extracts and capsules are a different matter. NIH’s National Center for Complementary and Integrative Health (NCCIH) publishes fact sheets on dozens of herbs and botanicals, but its Herbs at a Glance series has no shiitake or mushroom entry, so there is no NCCIH statement to report. A 2024 review uses shiitake to explain how a whole mushroom or extract differs from isolated compounds such as lentinan and eritadenine. This guide makes no health claims for shiitake supplements or their compounds. If you are considering one, our third-party tested supplements guide explains what independent testing can and cannot show, and our lion’s mane and reishi guides cover two other mushrooms sold as supplements.

How to cook shiitake

• Cleaning: wipe the caps with a damp cloth or rinse briefly and pat dry.
• Trimming: pull or cut off the woody stems; save them for stock.
• Sauteing: slice the caps and cook in a hot pan with a little oil, stirring until they are soft throughout and browned at the edges.
• Simmering: add sliced shiitake to soups and braises early enough that they cook through rather than floating in at the end.
• Pairings: shiitake work well with garlic, scallions, bok choy, ginger and sesame.

Safety and allergy notes

Shop for shiitake in grocery stores and markets, which sell farmed mushrooms. Wild mushroom poisoning is serious: a 2017 CDC report on death cap mushrooms in Northern California describes 14 poisonings in December 2016, including three liver transplants, and urges the public not to eat foraged wild mushrooms. A 2021 DNA study of US products labeled “wild mushrooms” also found that a few contained species of doubtful edibility. This guide gives no advice about wild mushrooms.

Mushrooms are not among the nine major food allergens that US labels must declare, but FDA notes that more than 160 other foods have been reported to cause allergic reactions. If you suspect a reaction to mushrooms, see an allergist, and read our elimination diet guide before cutting foods on your own.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Portobello Nutrition, Portobello vs Cremini and Cooking Tips, Lion’s Mane: What the Research Shows and Side Effects, Reishi Mushroom Benefits: Evidence, Liver Safety and Warfarin, Vitamin D Foods: 17 Sources Ranked With USDA Data.