Shiitake
Useful mainly for people wanting a culinary medicinal mushroom; UV-exposed shiitake as a vegetarian vitamin D2 source.
Quick decision guide
May help most
people wanting a culinary medicinal mushroom; UV-exposed shiitake as a vegetarian vitamin D2 source
Common dosing range
500–2,000 mg/day extract; 5–10 g dried mushroom culinary
When to expect effects
Weeks
Watch out for
Eat cooked; raw or undercooked shiitake can cause a distinctive whip-like dermatitis
What is it
Shiitake (Lentinula edodes) is a culinary and medicinal mushroom native to East Asia and widely cultivated worldwide. It is consumed as a food and is the source of lentinan, a beta-glucan polysaccharide used in Japan as a chemotherapy adjunct.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
cancer adjuvant (lentinan) Good Evidence | Modest survival/quality-of-life signal (injectable) | cancer patients receiving injectable lentinan alongside chemotherapy | Weeks to months |
immune function Limited Evidence | Immune-marker changes | generally healthy adults interested in immune support | Weeks |
cholesterol management Mixed Evidence | Uncertain | not established | Weeks |
cancer adjuvant (lentinan)
- Effect
- Modest survival/quality-of-life signal (injectable)
- Best fit
- cancer patients receiving injectable lentinan alongside chemotherapy
- Time
- Weeks to months
immune function
- Effect
- Immune-marker changes
- Best fit
- generally healthy adults interested in immune support
- Time
- Weeks
cholesterol management
- Effect
- Uncertain
- Best fit
- not established
- Time
- Weeks
Evidence for 3 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
cancer adjuvant (lentinan)
Disease adjunctLentinan, a beta-1,3-glucan from shiitake, is approved in Japan as an injectable chemotherapy adjuvant and has improved quality of life and modestly extended survival in some gastric cancer trials when added to chemotherapy. These results are for the injectable drug; oral supplemental lentinan has not been shown to reproduce them.
Bottom line: Injectable lentinan is an established chemo adjuvant in Japan, but oral shiitake supplements are not proven equivalents.
Evidence is mixed
Benefit is demonstrated for injectable lentinan with chemotherapy, not for oral shiitake extract.
immune function
Biomarker supportA small trial found that daily cooked shiitake intake shifted immune-cell markers and cytokine profiles toward enhanced cellular immunity and reduced inflammation. These are biomarker changes in a small study and do not show fewer infections or other clinical benefit.
Bottom line: May modulate immune markers, but clinical immune benefit is not established.
cholesterol management
Biomarker supportShiitake contains eritadenine, which lowers cholesterol in animal studies by altering phospholipid methylation. Human evidence is minimal, so any lipid (biomarker) effect in people is unproven.
Bottom line: Cholesterol lowering is an animal-level finding without solid human support.
How it works
How to take it
What to track
4 commercial forms
Compare the main delivery options and what they’re best suited for.
Fresh or dried mushroom
The traditional and most palatable form. Dried mushrooms retain bioactives and have concentrated flavor.
Provides full nutrient and bioactive profile; cook thoroughly.
Shiitake mycelium powder
Some products contain mycelium grown on grain substrate, which dilutes mushroom-derived compounds. Check for actual mushroom content.
Variable bioactive content depending on production.
Standardized extract
Capsule form for supplemental use. Look for products standardized to beta-glucan content.
Concentrated polysaccharides; absorption is partial.
Lentinan (injectable)
Clinical pharmaceutical form used in Japan for cancer adjunct therapy; not available as an over-the-counter supplement.
Bypasses oral absorption limitations.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
shiitake dermatitis (whip-like rash) from raw or undercooked mushroom
Who should avoid it
- people with mushroom allergy
- those on immunosuppressants or in cancer treatment without clinician input (concentrated extracts)
Pregnancy & breastfeeding
Culinary amounts are considered safe; high-dose extract safety in pregnancy and breastfeeding is not established.
Interactions
lentinan's immune-stimulating effects may oppose them
eritadenine could theoretically add to lipid effects
Food sources
| Food | Amount | %DV |
|---|---|---|
| Fresh shiitake mushrooms (1 cup cooked) | approx 80 grams, providing fiber, B vitamins, copper | — |
| Dried shiitake mushrooms (1 oz) | approx 28 grams dried (rehydrates to ~1 cup) | — |
| UV-exposed shiitake (1 oz) | Can provide 100-400% DV vitamin D2 | — |
Fresh shiitake mushrooms (1 cup cooked)
- Amount
- approx 80 grams, providing fiber, B vitamins, copper
- %DV
- —
Dried shiitake mushrooms (1 oz)
- Amount
- approx 28 grams dried (rehydrates to ~1 cup)
- %DV
- —
UV-exposed shiitake (1 oz)
- Amount
- Can provide 100-400% DV vitamin D2
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
Can I eat shiitake raw?⌄
No. Raw or undercooked shiitake can cause shiitake dermatitis, a distinctive linear rash that develops a day or two after eating. Cooking destroys the responsible compound.
What makes UV-exposed shiitake special?⌄
Shiitake mushrooms contain ergosterol, which converts to vitamin D2 when exposed to UV light. Commercially UV-exposed shiitake can provide significant dietary vitamin D, especially valuable for vegetarians and vegans.
Are shiitake supplements as good as eating the mushroom?⌄
Both have value. Whole mushrooms provide a complete profile of nutrients and bioactives along with fiber. Concentrated extracts deliver higher doses of polysaccharides for specific applications.
Is shiitake safe for daily consumption?⌄
Yes, regular culinary consumption is safe and may have health benefits. Avoid very large daily doses of concentrated extracts without consulting a clinician.
What is lentinan?⌄
Lentinan is a beta-glucan polysaccharide isolated from shiitake that is used as an injectable cancer adjunct in Japan. Oral lentinan supplements have less established efficacy.
References by claim
Track Shiitake with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.