Reishi Dosage & Consumption

What this page covers: the exact doses used in named Reishi clinical trials, what powder, tea, tincture, and capsule forms actually extract from the mushroom, and the drug interactions clinical summaries report. It does not evaluate specific supplement products or make treatment claims. See the NCBI Bookshelf LiverTox entry for a fuller clinical picture.

In one line

Published doses range from 200 mg/day of a standardized beta-glucan extract to 3 g/day of whole extract, and the consumption method (tea, tincture, capsule) determines which compound class actually reaches the body; Reishi can also meaningfully interact with blood thinners.

Doses used in published research

A trial measuring immune-cell markers in 135 healthy adults age 18 to 55 used 200 mg/day of a standardized Ganoderma lucidum beta-1,3;1,6-D-glucan extract for 84 days, per Chen et al., 2023, Foods. A separate trial in 84 adults with type 2 diabetes and metabolic syndrome used a much larger dose, 3 g/day of whole Ganoderma lucidum extract (eight capsules daily), for 16 weeks, per Klupp et al., 2016, Scientific Reports, and found no significant improvement in blood glucose, blood pressure, or cholesterol at that dose in that population.

Reishi doses by named study
Study	Population	Dose	Duration
Chen et al., 2023, Foods	Healthy adults 18-55 (n=135 completed)	200 mg/day standardized beta-1,3;1,6-D-glucan extract	84 days
Klupp et al., 2016, Scientific Reports	Adults with type 2 diabetes and metabolic syndrome (n=84 randomized)	3 g/day whole Ganoderma lucidum extract (8 capsules/day)	16 weeks

Powder, tea, tincture, or capsule: what each form extracts

Reishi's two most-studied compound classes, beta-glucans (polysaccharides) and ganoderic acids (triterpenes), don't dissolve in the same solvent. That means the consumption method changes what actually ends up in the body, independent of dose.

Consumption method vs. what it extracts
Method	What it extracts	Worth knowing
Powder / decoction (tea)	Primarily water-soluble beta-glucans; simmering dried Reishi slices or powder in water for an extended time is the traditional preparation.	Won't meaningfully extract ganoderic acids (triterpenes), which require alcohol, not just hot water, to come out of the fungal material.
Tincture (alcohol extraction)	Primarily ganoderic acids (triterpenes) and other alcohol-soluble compounds.	Won't meaningfully extract beta-glucans on its own, which is why commercial dual-extract products combine a water step with an alcohol step.
Dual-extract capsule or powder	Both beta-glucans and ganoderic acids, when the product discloses both a water and an alcohol extraction step.	Check the label for both a beta-glucan percentage and a triterpene/ganoderic-acid percentage; a product listing only one figure likely only ran one extraction step.

Reported side effects

Per Memorial Sloan Kettering Cancer Center's clinical summary, reported effects include nausea, insomnia, dry mouth, constipation, itching, and vertigo. Case reports document rare instances of liver injury, including one fatal case reviewed on the NCBI Bookshelf LiverTox entry, which assigns Reishi its lowest likelihood category for causing liver injury and notes many reported cases were poorly documented, with other causes not fully excluded.

Drug interactions worth knowing

Per MSKCC's clinical summary, Reishi can increase bleeding risk and may prolong INR, PT, and APTT lab values in people taking anticoagulants or antiplatelet medications. A published case report describes a hemodialysis patient on warfarin whose INR rose to 6.92 and then 8.22 following ingestion of Ganoderma lucidum extract tablets, per Minerva Medica, 2020. MSKCC also notes a possible interaction with immunosuppressant medications, since Reishi may enhance immune response. Anyone on prescription medication, especially blood thinners or immunosuppressants, should talk to a doctor before starting Reishi.

This page doesn't evaluate how any specific supplement product's label dose compares to these study doses; see the Reishi hub for named-brand extraction comparisons, or the individual brand reviews linked from that page.

Frequently Asked Questions

What dose of Reishi was used in clinical trials?

It varies widely by what was studied. A trial measuring immune-cell markers in healthy adults used 200 mg/day of a standardized beta-glucan extract for 84 days (Chen et al., 2023). A separate trial testing metabolic outcomes in adults with diabetes used 3 g/day of whole extract for 16 weeks (Klupp et al., 2016) and found no benefit. The doses aren't interchangeable; they tested different extract types in different populations.

Does Reishi tea or powder work the same as capsules?

Not necessarily. A hot-water preparation like tea or a simple decoction mainly extracts beta-glucans, not ganoderic acids (triterpenes), which need an alcohol extraction step. A capsule or powder product that discloses only a beta-glucan percentage was likely made the same way; one that also lists a triterpene percentage used a dual extraction method.

What are the reported side effects of Reishi?

Per Memorial Sloan Kettering Cancer Center's clinical summary, reported effects include nausea, insomnia, dry mouth, constipation, itching, and vertigo. Case reports also document rare instances of liver injury, including one fatal case, though the NCBI Bookshelf LiverTox review notes these cases are extremely uncommon and often poorly documented.

Does Reishi interact with blood thinners?

Yes. Per Memorial Sloan Kettering's clinical summary, Reishi can increase bleeding risk and may prolong INR, PT, and APTT lab values in people taking anticoagulants. A published case report describes a hemodialysis patient on warfarin whose INR rose to 6.92 and then 8.22 following ingestion of Ganoderma lucidum extract tablets (Minerva Medica, 2020). Anyone taking warfarin or another blood thinner should talk to a doctor before using Reishi.

Who else should be cautious with Reishi?

Per Memorial Sloan Kettering's clinical summary, Reishi may interact with immunosuppressant medications (since it can enhance immune response) and with drugs metabolized by certain cytochrome P450 enzymes. People with a known mushroom allergy, anyone on prescription medication, and anyone pregnant or nursing should check with a doctor before use.

Sources

Chen et al., 2023, Foods: Randomized, double-blind, placebo-controlled trial: 200 mg/day Ganoderma lucidum beta-glucan for 84 days in healthy adults (n=135 completed)
Klupp et al., 2016, Scientific Reports: Double-blind, randomized, placebo-controlled trial: 3 g/day Ganoderma lucidum for 16 weeks in adults with type 2 diabetes and metabolic syndrome; found no significant benefit on cardiovascular risk factors
Memorial Sloan Kettering Cancer Center, Reishi Mushroom clinical summary: Reported adverse effects, anticoagulant/antiplatelet and immunosuppressant drug interactions, and population-specific warnings
NCBI Bookshelf, LiverTox: Lingzhi, Reishi: Clinical safety review; typical doses 500 mg-3 g/day, likelihood category D for liver injury
Minerva Medica, La Rivista Italiana della Medicina di Laboratorio, 2020: Case report: suspected Ganoderma lucidum-warfarin interaction in a hemodialysis patient, INR rose to 6.92 and 8.22