Reishi Mushroom and Blood Pressure: Evidence-Based Assessment
Direct Answer
Reishi mushroom (Ganoderma lucidum) is not recommended for blood pressure management in adults with hypertension who are already taking antihypertensive medications, as high-quality clinical evidence shows no clinically meaningful blood pressure reduction, and its use is not endorsed by any major hypertension guideline. 1
Evidence Quality and Guideline Position
Absence of Guideline Support
No major hypertension guideline—including the 2024 European Society of Cardiology, 2022 World Health Organization, or 2017 American College of Cardiology/American Heart Association—recommends or even mentions Ganoderma lucidum as a therapeutic option for blood pressure control. 1, 2
The WHO strongly recommends thiazide/thiazide-like diuretics, ACE inhibitors, ARBs, or long-acting dihydropyridine calcium channel blockers as first-line agents, with high-quality evidence supporting cardiovascular outcome benefits that reishi mushroom has never demonstrated. 1, 3
Clinical Trial Evidence Shows No Benefit
A 2015 Cochrane systematic review of five randomized controlled trials (398 participants total) found that Ganoderma lucidum produced no statistically or clinically significant reduction in blood pressure when compared to placebo. 4
The Cochrane review specifically analyzed participants with type 2 diabetes receiving 1.4–3 g of reishi daily for 12–16 weeks and found no improvement in systolic or diastolic blood pressure, HbA1c, total cholesterol, LDL cholesterol, or body mass index. 4
The review concluded that "evidence from a small number of randomised controlled trials does not support the use of G. lucidum for treatment of cardiovascular risk factors in people with type 2 diabetes mellitus." 4
Animal Data Cannot Be Extrapolated to Humans
A 2018 rat study showed that seven weeks of intragastric reishi water extract reduced blood pressure in hypertensive ISIAH rats to a level comparable to losartan, but this finding has never been replicated in human clinical trials and does not justify clinical use. 5
Animal models frequently demonstrate pharmacological effects that fail to translate to human efficacy, and the absence of confirmatory human data means this rat study provides no actionable clinical guidance. 5
Safety Considerations for Concurrent Use
Potential Drug Interactions
Adults already taking antihypertensive medications who add reishi mushroom face theoretical risk of additive hypotensive effects, although the Cochrane review found no serious adverse events in clinical trials. 4
Participants taking reishi for four months were 1.67 times more likely to experience an adverse event than those on placebo (RR 1.67,95% CI 0.86–3.24), though these were not serious side effects. 4
Lack of Standardization
Reishi preparations vary widely in active compound content (polysaccharides, triterpenoids, peptides) depending on extraction method, geographic origin, and processing technique, making dose-response relationships impossible to establish. 6, 7, 8
The inconsistent evidence across studies is attributed to the use of different Ganoderma formulations and different study populations, further undermining any recommendation for clinical use. 6
Evidence-Based Hypertension Management Instead
Proven First-Line Therapy
For adults with confirmed hypertension (≥140/90 mmHg), initiate pharmacological treatment immediately with thiazide diuretics, ACE inhibitors, ARBs, or long-acting dihydropyridine calcium channel blockers—all of which have robust cardiovascular outcome data that reishi mushroom lacks. 1, 2
For stage 2 hypertension (≥140/90 mmHg), begin with a two-drug combination from different first-line classes, preferably as a single-pill formulation, to achieve faster blood pressure control and improve adherence. 1, 2
Blood Pressure Targets
The ACC/AHA guideline targets <130/80 mmHg for adults with established cardiovascular disease or 10-year ASCVD risk ≥10%, while the WHO guideline targets <140/90 mmHg for individuals without comorbidities. 1, 2
For non-institutionalized adults aged ≥65 years with systolic ≥130 mmHg, the target is <130 mmHg if tolerated. 1, 2
Common Pitfalls to Avoid
Do not delay or substitute proven antihypertensive therapy with reishi mushroom, as this exposes patients to preventable cardiovascular events including stroke, myocardial infarction, and heart failure. 1
Do not assume that "natural" or traditional remedies are inherently safe or effective; the absence of serious adverse events in short-term trials does not establish long-term safety or justify use in place of guideline-directed therapy. 4, 6
Do not rely on animal studies or in vitro data to guide clinical decisions when high-quality human randomized controlled trials show no benefit. 5, 6
Bottom Line
Reishi mushroom has no established role in blood pressure management based on current clinical evidence, and adults with hypertension should receive guideline-directed pharmacotherapy (thiazide diuretics, ACE inhibitors, ARBs, or calcium channel blockers) that has proven cardiovascular outcome benefits. 1, 4