Evidence explainerReishi mushroom
Reishi Mushroom Side Effects: Well Tolerated in Trials, With Rare Liver Case Reports
Short trials found reishi well tolerated. LiverTox, the NIH liver-injury database, notes rare single cases of acute liver injury, most with other causes not ruled out.
Key takeaways
- In a 10-day trial of 4 g/day, there were no adverse effects versus placebo on questionnaires, ECG, blood tests or urinalysis [1].
- In the Cochrane review, adverse events were 1.67 times as likely with reishi over four months, though the confidence interval crossed 1 and none were serious [2].
- LiverTox says reishi has not been linked to liver-enzyme rises in trials, but has been implicated in rare single cases of acute liver injury [3].
- One published case describes acute liver injury after reishi powder taken with alcohol, with labs back to normal at two weeks [4].
The evidence, graded
Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.
- Grade DNo effectShort-term safety and immune cell countsNo 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.
- Grade CNo effectHbA1c, cholesterol and body-mass indexNo 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.
What trials found
In a 10-day placebo-controlled trial, 16 healthy volunteers took 2 g of reishi extract twice daily [1]. Compared with placebo, no adverse effects appeared on questionnaires, electrocardiograms, blood counts, blood chemistry or urinalysis [1].
Across the longer trials in the Cochrane review (12 to 16 weeks), adverse events were more common with reishi, but the result was not statistically certain and no serious events were reported [2].
The liver question
LiverTox describes reishi as well tolerated and not associated with liver-enzyme elevations during trials [3]. It has, however, been implicated in rare single cases of acute liver injury, and in most reports other diagnoses were not adequately excluded [3].
A 2023 case report describes a 47-year-old man with acute hepatitis after taking reishi powder with alcohol; his symptoms and lab values had fully resolved at a two-week follow-up [4].
Who should be careful
Anyone with liver disease, who drinks alcohol regularly or takes prescription medicines should talk to a clinician before using reishi. For what the trials found on benefits, read reishi mushroom benefits.
Quick answers
Keep reading
Full monographs
Related articles
- Reishi Mushroom Benefits: Few Human Trials, and the Biggest Review Found No Effect
- 400 IU of Vitamin E Is Either 268 mg or 180 mg. The "d" or "dl" on the Label Decides
- Alpha-GPC vs Choline Bitartrate: Blood Choline Rose the Same, but One Detail Differed
- B12 After 50 and on Metformin: Why Levels Drop, and What the Trials Say About Fixing Them
Browse the full Supplement & Nutrient Encyclopedia or all supplement articles.
References
- [1]Safety and tolerability of Ganoderma lucidum in healthy subjects: a double-blind randomized placebo-controlled trial. Am J Chin Med, 2007.
- [2]Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev, 2015.
- [3]Lingzhi, Reishi (LiverTox: Clinical and Research Information on Drug-Induced Liver Injury). National Institute of Diabetes and Digestive and Kidney Diseases (LiverTox), 2012.
- [4]Ganoderma lingzhi (Reishi Mushroom)-Induced Acute Liver Injury in the Setting of Alcohol Use: A Case Report and Review of the Literature. Cureus, 2023.