Reishi mushroom
Summary
Human evidence for reishi is sparse. A Cochrane review found no improvement in blood sugar, cholesterol or blood pressure over 12–16 weeks. Small short trials found it well tolerated and raised blood antioxidant capacity briefly. LiverTox reports rare single cases of acute liver injury, most with other causes not excluded.
Key facts
- No head-to-head human data between reishi products in our sources[1]
- Blood sugar, cholesterol and body-mass index: no effect (C); short-term safety and immune cell counts: no adverse effects, no significant change (D); blood antioxidant capacity ↑ briefly (D)[1][2][3]
- Well tolerated and not associated with liver-enzyme elevations in trials; implicated in rare single cases of acute liver injury. In a Cochrane review, non-serious adverse events were somewhat more common than with placebo[4][2][1]
- 3 graded human outcomes on this page
- October 9, 2026
How it works
ProposedReishi is reputed to have antioxidant properties. A single 1.1 g amount raised plasma antioxidant capacity within 90 minutes in 10 volunteers, but longer-term human effects are not established (proposed).[3]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Metabolic | Grade C | No effect | Meta-analysis · n = 130 · 2015 | 1 row |
| Immune | Grade D | No effect | RCT · n = 16 · 2007 | 1 row |
| Healthy aging | Grade D | Improved | Crossover RCT · n = 10 · 2004 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| HbA1c, cholesterol and body-mass index | No effect | Grade C | Meta-analysis · n = 130 · 2015 Adults with type 2 diabetes in the trials with usable data (Cochrane review of 5 trials, 398 participants) Form: Ganoderma lucidum vs placebo · Dose: 1.4–3 g/day · Duration: 12–16 weeks No statistically or clinically significant reduction in HbA1c, total or LDL cholesterol, or body-mass index; fasting glucose did not improve, and blood pressure and triglycerides did not differ. Adverse events were 1.67 times as likely with reishi over four months (confidence interval crossing 1), none serious. | 25686270 (opens PubMed)Source [1] |
| Short-term safety and immune cell counts | No effect | Grade D | RCT · n = 16 · 2007 Healthy volunteers Form: Ganoderma lucidum extract vs placebo · Dose: 2 g twice daily (4 g/day) · Duration: 10 days No adverse effects compared with placebo on questionnaires, ECG, blood counts, blood chemistry or urinalysis. CD4, CD8 and CD19 counts did not change; a CD56 rise was not statistically significant. | 17597499 (opens PubMed)Source [2] |
| Blood and urine antioxidant markers | Improved | Grade D | Crossover RCT · n = 10 · 2004 Healthy volunteers Form: Lingzhi (Ganoderma lucidum) vs placebo · Dose: 1.1 g once; then 0.72 g/day · Duration: Single amount and 10 days Plasma antioxidant capacity rose after a single amount (peak at 90 minutes) and urine antioxidant capacity rose 29% within 3 hours. After 10 days, fasting plasma alpha-tocopherol and urine antioxidant capacity increased. | 14630595 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Reishi extract or dried mushroom powder | Varies[2] | Antioxidants from a single 1.1 g amount appeared in plasma within 90 minutes.[3] | No adverse effects versus placebo at 4 g/day extract for 10 days.[2] | Blood sugar and cholesterol, immune markers, antioxidant markers |
Studied doses
Doses studied in human trials ranged from 0.72 to 4 g of reishi a day, for 10 days to 16 weeks.[3][2][1]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Other supplements
- AlcoholCase reportA published case describes acute liver injury after reishi powder taken with alcohol, with labs back to normal at two-week follow-up.[5]
Who should be careful
- Liver concerns
- LiverTox notes reishi has been implicated in rare single cases of acute liver injury, although other causes were often not adequately excluded; one reported case involved reishi powder with alcohol.[4][5]
- Before you start
- Talk to your pharmacist or clinician before adding this supplement, especially if you take prescription medicines, are pregnant or breastfeeding, or have a chronic health condition.[4]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Articles about Reishi mushroom
Plain-English answers to common questions, built on the evidence above.
Frequently asked questions
Does reishi lower blood sugar or cholesterol?
A Cochrane review found no significant effect on HbA1c, cholesterol or body-mass index in trials of 1.4–3 g/day for 12–16 weeks.[1]
Does reishi change immune cell counts?
In a 10-day trial of 16 healthy volunteers, 4 g/day of extract did not significantly change CD4, CD8, CD19 or CD56 immune cell counts.[2]
Is reishi safe for the liver?
LiverTox says reishi is well tolerated and not associated with liver-enzyme rises in trials, but it has been implicated in rare single cases of acute liver injury.[4]
Is reishi an antioxidant?
A single amount raised plasma antioxidant capacity for a few hours in 10 volunteers. Whether this matters for health is unknown.[3]
Sources
- [1]Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors.. Cochrane Database Syst Rev, 2015. meta-analysis
- [2]Safety and tolerability of Ganoderma lucidum in healthy subjects: a double-blind randomized placebo-controlled trial.. Am J Chin Med, 2007. RCT
- [3]Ganoderma lucidum ('Lingzhi'); acute and short-term biomarker response to supplementation.. Int J Food Sci Nutr, 2004. crossover-RCT
- [4]Lingzhi, Reishi (LiverTox: Clinical and Research Information on Drug-Induced Liver Injury). National Institute of Diabetes and Digestive and Kidney Diseases (LiverTox), 2012. database
- [5]Ganoderma lingzhi (Reishi Mushroom)-Induced Acute Liver Injury in the Setting of Alcohol Use: A Case Report and Review of the Literature.. Cureus, 2023. observational
What changed
- First draft. Every evidence-row PMID checked with NCBI E-utilities (esummary + efetch abstract) and re-read in an independent adversarial pass.