Mushroom Atlas

Shiitake Dosage & Consumption

What this page covers: the exact amounts used in published trials for whole shiitake, lentinan, and AHCC, and how each compares across forms. It does not evaluate specific supplement products or make treatment claims. See the Shiitake hub for the full research context behind each form.
In one line

The clearest trial dose is food-level: 5-10 g/day of whole dried shiitake for 4 weeks. AHCC and lentinan are different products studied at their own doses and routes (AHCC orally, 3 g/day total; lentinan intravenously), neither directly comparable to eating the mushroom.

Trial doses by form

Shiitake trial doses, by form and study
StudyPopulationDose & durationOutcome
Dai et al., 2015, J Am Coll Nutr52 healthy adults, ages 21-415 or 10 g/day dried whole shiitake, eaten, for 4 weeksγδ-T cells +60% (P<.0001), NK-T cells doubled (P<.0001), higher salivary IgA, lower CRP
Kamiyama et al., 2022, Integrative Cancer Therapies (AHCC)29 post-hepatectomy liver cancer patients (25 completed)AHCC 1 g, 3x/day (3 g/day total), oral, for 2 years2-year recurrence-free survival 55.2% (all treated) / 48% (completers); single-arm, uncontrolled, small sample
Lentinan trials (per MSK summary)Varies by trial, mostly cancer patients alongside chemotherapyIntravenous administration under medical supervision; not an oral consumer doseMixed results by cancer type; not applicable to any oral supplement dose

Why the three forms aren't interchangeable

Whole shiitake, lentinan, and AHCC are different products with different evidence bases. Whole shiitake's evidence comes from eating the food itself. Lentinan's evidence comes from an intravenous, medically-supervised extract, not something sold as a US retail supplement dose. AHCC's evidence comes from a small, single-arm, uncontrolled trial in a specific patient population (post-surgical liver cancer patients), at a specific oral dose (3 g/day total), that the study authors themselves flagged as needing confirmation in a larger, controlled trial. None of these doses should be read as a general recommendation; see the Shiitake hub for what each study population and limitation actually was.

Safety at the doses studied

Neither the Dai et al. nor the Kamiyama et al. trial reported serious adverse events at the doses tested. Separately, per Memorial Sloan Kettering's summary, shiitake and its extracts have been associated with skin reactions (including flagellate dermatitis), gastrointestinal upset, and eosinophilia in some people. This page doesn't evaluate individual medication interactions; anyone with a mushroom allergy, anyone pregnant or breastfeeding, and anyone on immune-modulating medication should talk to a doctor before starting shiitake, lentinan, or AHCC at any dose. For raw-vs-cooked identification and the dermatitis-toxin mechanism specifically, see the Shiitake ID page.

Frequently Asked Questions

How much shiitake do I need to eat to match the research?

The only human trial on this site's Shiitake page used 5 or 10 grams per day of dried whole shiitake, eaten daily for 4 weeks, in healthy adults (Dai et al., 2015). That's a food-level amount, roughly 1-2 medium dried mushrooms depending on size, not a supplement-label dose.

What dose of AHCC was used in the recurrence study?

1 gram, three times daily (3 g/day total), taken orally for 2 years, per Kamiyama et al., 2022. That trial was single-arm and uncontrolled with a small patient count, so treat the dose as what was tested, not as an established effective dose.

Can I take lentinan as an oral supplement instead of IV?

The trials behind lentinan's evidence used intravenous administration under medical supervision in Japan. No source used on this site's Shiitake pages establishes an equivalent oral consumer dose, so an oral lentinan product's dose can't be compared to those trial results.

Does cooking change shiitake's studied compounds?

This page doesn't test that specifically. Dai et al., 2015 used dried whole shiitake as a food; for how raw vs. cooked shiitake affects a separate compound, the dermatitis-triggering lentinan-related toxin, see the identification page linked below.

Sources