Medicinal Mushrooms and Blood Pressure: What the Research Actually Tested — and What It Found

In brief5 points · 1-minute read

• Reishi is the only mushroom tested for blood pressure in humans: a Cochrane review (398 participants) and a 2025 meta-analysis (971 participants) found no difference versus placebo.
• The only cordyceps figure (systolic −4.57, diastolic −3.96 mmHg) comes from diabetic kidney disease patients already on an ACEI/ARB drug, across 51 trials.
• The strongest human finding runs the other way: in 33 patients, two weeks of reishi at 3 grams daily cut platelet aggregation by 31.49%.
• Lion's mane has never been measured for blood pressure in any system, and the rat results for shiitake, maitake and agaricus did not repeat in humans.
• What is evidence-based instead: the DASH diet lowered systolic pressure by 3.2 mmHg across 30 trials with 5,545 participants. Mushrooms are not part of it.

Questions about this article? Ask the Triterra bot ›

Reishi (Ganoderma lucidum), the lingzhi of traditional Chinese medicine, is the medicinal mushroom the “lowers blood pressure” claim leans on most — and the only one of the four we grow that has been tested for it in humans. When it was measured, blood pressure did not fall: a Cochrane review and a 2025 meta-analysis of 17 randomized trials in 971 participants found no significant difference from placebo.

The kinds of evidence that do exist, from closest to a human to farthest: two meta-analyses of randomized trials on reishi, both with no change in blood pressure; one crossover trial that recruited people with borderline blood pressure, also with no change; one meta-analysis on cordyceps — in diabetic kidney disease patients already taking a blood-pressure drug; rats; enzyme inhibition in a dish; and one human study on platelets, in which reishi did do something measurable — in the direction of bleeding. On lion’s mane: zero measurements, in any living organism.

Do medicinal mushrooms lower blood pressure?

No, according to what has been measured in humans. Reishi is the only mushroom tested in controlled trials, and in two meta-analyses — 398 and 971 participants — blood pressure did not fall versus placebo. On lion’s mane there is no measurement. On cordyceps there is one human number, from a different population. The claim rests on rats and on dishes.

On most of our condition pages the answer is “unknown, because nobody tested it.” Here it is stronger and less convenient: it was tested, in randomized double-blind trials, and blood pressure did not move. We grow reishi and we sell it — and that is exactly why this finding has to be written down. The page walks the whole chain: what was measured, what came out, where the myth came from, and what someone taking a blood-pressure drug does need to know — because there, and not in the benefit, sits the strongest human finding.

What has been measured for each mushroom — and in which system?

The table sorts ten mushrooms by the human evidence that exists on them and by the highest grade they have reached. Only three rows contain a randomized trial in humans that measured blood pressure — reishi, agaricus and culinary mushrooms — and in all three the result is the same: no change. Everything else is rats, test tube, or nothing.

What exactly did the Cochrane review test — and what did it find?

The 2015 Cochrane review searched every Western and Chinese database, with no language restriction, and found five trials totalling 398 participants. Three of them, with 157 participants, supplied data: reishi 1.4–3 grams a day versus placebo, 12–16 weeks. Its conclusion: no significant difference in blood pressure, nor in any other cardiovascular risk factor.

All the participants in the three trials analysed were type 2 diabetes patients — even the best evidence that exists is not from people recruited because of their blood pressure. The blood-pressure data came from a single study of 84 participants, and so were reported in words rather than as a pooled number: “no statistically significant differences between groups in blood pressure or triglycerides.” HbA1c (−0.10%), cholesterol, LDL and BMI did not move either. What did move: the odds of an adverse event, 1.67 times (95% confidence interval: 0.86–3.24) — nausea, diarrhoea or constipation. The authors’ conclusion: the evidence does not support the use of reishi for the treatment of cardiovascular risk factors. Anyone who quotes you “the Cochrane review on reishi” as support has not opened it.

And what did the 2025 meta-analysis and the one borderline-blood-pressure trial say?

The same, with more people. The 2025 meta-analysis pooled 17 randomized trials in 971 participants, at doses from 200 to 11,200 mg a day, and found no effect on blood pressure. The only trial that recruited people with borderline blood pressure — 26 participants, 1.44 grams a day, 12 weeks — reported no change, on reishi or on placebo.

The 2025 meta-analysis is the most recent and the broadest: a search through August 2024, healthy, at-risk and patient populations, durations from one week to 24 weeks. It did find significant reductions in BMI (−0.43) and in heart rate (−3.92 beats per minute; P=0.029), and stated explicitly: “no significant effects were observed on body fat, waist circumference, blood pressure, fasting glucose, lipid profile, inflammatory markers or liver enzymes.” The quality of evidence was rated very low by GRADE for every outcome. A drop in heart rate without a drop in blood pressure is not “the beginning of an effect” — it is a separate finding; we go into it on the heart page.

The 2012 crossover trial is the only one in the world that recruited people because of their blood pressure: 26 patients with borderline elevations in blood pressure or cholesterol, 23 evaluable. Insulin and HOMA-IR were lower after reishi, but significant carry-over effects between the trial periods prevented a full analysis of the lipids. Reishi was well tolerated. Blood pressure: no change.

If it was measured and came out zero — why does half the internet say otherwise?

Because the claim was born before the measurement. The chain starts with a 1985 Japanese publication whose title promises “efficacy against hypertension and side effects” — no abstract on PubMed, not classified as a controlled trial. From there the claim passed into reviews that write “reported” without citing, and from review to review without anyone going back to the source.

The first link: the 1985 publication, in Japanese, 41 years old. What can be said about it from the metadata alone: a journal article carrying an “English abstract” tag — not a randomized trial, not a clinical trial. Number of participants, dose and result are not available, and so are not written here either. The second link: a 2007 review that writes that triterpenoids from reishi “have been reported” to have antihypertensive effects — without citing a study, without a dose, without an experimental system. The third link: a 2025 review of herbal drugs in cardiovascular disease that lists reishi among those “known” for treatment, and closes by calling for further research to understand the mechanism. A mention in a list is not evidence, and the review admits as much itself.

And there is a fourth link, more cunning: a genuine randomized trial in 42 healthy volunteers (225 mg of reishi, six months) that measured oxidation markers and liver enzymes, and mentions hypertension only in its opening sentence, as a traditional use. Blood pressure was not measured in it at all. Online it appears as “a clinical study of reishi and blood pressure.” That is how a background mention becomes a finding.

What was found in rats and in the test tube — and why did it not hold up in humans?

In hypertensive rats, reishi did lower blood pressure — in a 1988 study with no abstract, and in a 2018 study that wrote “at a level similar to losartan.” In a dish, proteins and peptides from reishi inhibit the ACE enzyme. Real findings, on rats and enzymes. The next step, humans, was taken — and blood pressure did not fall.

The classic animal model — reishi in the diet of spontaneously hypertensive rats — is a single piece of work from 1988, which the direct PubMed search returns as its only result and which has no abstract; there is no number from it to quote. In 1990 a reishi mycelium extract lowered blood pressure in rabbits and anaesthetized rats, given parenterally, while heart rate did not fall — from which a central mechanism of sympathetic-outflow suppression was inferred. An anaesthetized animal with a catheter in an artery is not a person swallowing a capsule. And the only comparison to a drug: in 2018, in ISIAH-strain rats with stress-induced hypertension, seven weeks of intragastric reishi lowered blood pressure “at a level similar to losartan.” “Similar to losartan in a rat” will be quoted a lot; it is not “like losartan in a human,” and the abstract does not even contain a mmHg number.

The mechanism behind all of this is ACE inhibition — the enzyme that ACE-inhibitor drugs block. Protein fractions from reishi mycelium inhibited ACE in vitro with an IC₅₀ of 1.134 mg per ml for the crude extract, and purified fractions went below 200 micrograms per ml. A peptide named QLVP, isolated from fermented mycelium, showed an IC₅₀ of 127.9 micromoles per litre and activated eNOS phosphorylation in cultured endothelial cells. Fermented mycelium, not fruiting body; cells in a dish, not blood pressure in a living organism. Inhibiting an enzyme in a dish is not lowering mmHg — otherwise every fortified yogurt would be a drug.

What does the only number on cordyceps and blood pressure really say?

That systolic fell by 4.57 and diastolic by 3.96 mmHg — in patients with diabetic kidney disease who were already taking an ACE inhibitor or an angiotensin-receptor blocker, when cordyceps was given as an add-on to the drug, in 51 trials almost all from Chinese databases. Without those three conditions the number misleads. In an ordinary hypertension group — never tested.

The meta-analysis (51 randomized trials, 3,955 participants) tested a fermented cordyceps preparation combined with an ACEI/ARB drug against the drug alone. The primary outcomes were renal — proteinuria, creatinine, urea — and blood pressure was a secondary endpoint: systolic −4.57 (95% confidence interval: −6.78 to −2.37), diastolic −3.96 (−5.73 to −2.19). A second, independent meta-analysis (38 trials, 3,167 patients) wrote only that “the adjunctive treatment also improved blood pressure outcomes” — with no number. Both in diabetic kidney disease patients; neither in people with hypertension.

And now the opposite finding, which no marketing page will tell you: in rats with doxorubicin-induced cardiotoxicity, fermented cordyceps at three doses (0.75, 1.5 and 3 grams per kg) improved cardiac indices — and in the same breath, according to the abstract, “raised diastolic blood pressure and mean arterial pressure.” The direct search — cordyceps, hypertension, humans, blood pressure in the title — returns zero. What is consistently documented for cordyceps is the anti-thrombotic direction: a 2013 review summarizes studies on reduced blood viscosity, resistance to platelet aggregation and anticoagulant activity. In other words, the interaction axis for cordyceps is with anticoagulants, not with blood-pressure drugs. More on the cordyceps safety page.

And what about lion’s mane and turkey tail?

On lion’s mane there is not one blood-pressure measurement — not in a human, not in an animal, not in a test tube. The search for lion’s mane or turkey tail with “blood pressure” in the title returns zero results. On turkey tail: one study in rats with metabolic syndrome, an isolated polysaccharide, and no mmHg number in the abstract.

And yet you will find “lion’s mane is antihypertensive” online. The source: a comprehensive 2015 review that lists the word among the mushroom’s “health-promoting properties,” alongside antidiabetic and neuroprotective — and presents not one blood-pressure measurement. The broadest search — lion’s mane with blood pressure, hypertension, antihypertensive or blood vessels — returns 19 publications, and not one of them measures blood pressure. Turkey tail: 40 Wistar rats in five groups, the mushroom’s heteropolysaccharides at 300, 200 or 100 mg per kg, four weeks; the high and medium doses lowered blood pressure (P<0.05). Rats with induced metabolic syndrome, an isolated polysaccharide, and mmHg — not stated. That is all there is.

The mushrooms that did lower blood pressure in rats — what happened when they were tested in humans?

Shiitake and maitake lowered blood pressure in SHR rats in 1987 — at 5% of the diet. Agaricus lowered blood pressure and heart rate in rats in 2014 — at 10% of the diet. When agaricus was tested in 57 women, 900 mg a day for 60 days — “no change from baseline was found in any parameter.” We sell none of these.

The study most often quoted as “mushrooms lower blood pressure” is from 1987: spontaneously hypertensive rats were given a diet with 5% mushroom powder and a salt solution as drinking water, for nine weeks. The mushrooms: shiitake and maitake — not reishi. If you see that study next to a picture of reishi — someone did not read the title. Agaricus is the instructive case, because it is the only one that went the whole way: in SHR rats fed pellets with 10% agaricus from 6 to 11 weeks of age, blood pressure and heart rate were significantly lower throughout the follow-up. Then the human trial: randomized, double-blind, placebo (29) versus dry extract 900 mg a day (28), 60 days, with blood-pressure measurement — and no change from baseline was found in any parameter, in either group. That is the pattern of the entire field, demonstrated in a single mushroom.

And culinary mushrooms on the plate? The best human evidence in the mushroom world: a randomized trial in 60 adults, all food provided, a Mediterranean diet with 84 grams a day of button and oyster mushrooms versus the same diet without mushrooms, eight weeks. The mushrooms improved fasting glucose (−2.9 versus 0.6 mg per dL; P=0.034) — and nothing else; blood pressure was among the factors that did not change. A systematic review of 22 papers explicitly rated blood pressure “inconsistent”; a second review, of seven prospective studies, concluded that it “has not been unequivocally demonstrated.” On shiitake and circulation we wrote separately.

I am on a blood-pressure drug — what do I need to know?

Three things. PubMed holds no interaction study between reishi and any blood-pressure drug — not beta-blockers, not ACE inhibitors, not calcium-channel blockers. Reishi did inhibit platelet aggregation by 31.49% in humans after two weeks — with no interaction study against anticoagulants. And potassium at a high dose raises blood pressure precisely in the already-treated. A data void is not a safety certificate.

Interaction with blood-pressure drugs: a data void. We searched reishi with amlodipine, losartan, metoprolol, beta-blockers and calcium-channel blockers — five publications, and not one of them is an interaction study; the drugs appear in them as background treatment. Reishi with cytochrome P450 — zero. The only place in the literature where reishi was given alongside blood-pressure drugs is a study in 14 nephrotic-syndrome patients, who were taking an ACE inhibitor, an angiotensin-receptor blocker, a calcium-channel blocker and an antiplatelet — and blood pressure was not an endpoint in it. The opportunity to measure was there, and nobody measured. The bottom line is not “safe” and not “dangerous” — it is “not tested,” and that is what to tell your doctor.

Bleeding: the strongest human finding in the whole file. In 33 patients with atherosclerotic disease taking reishi 1 gram three times a day for two weeks, inhibition of ADP-induced platelet aggregation reached 31.49% (P<0.01), and the length of the extracorporeal thrombus fell from 30.05 to 20.4 mm. A realistic dose, after two weeks. The mechanism is known: ganodermic acid S at a concentration of 2 micromolar inhibited 50% of platelet aggregation in response to a thromboxane mimetic, and at 7.5 micromolar — over 95%; and in a follow-up study the same compound amplified the platelet response to PGE1 up to 1.8-fold — meaning the effect adds to that of other agents. That is an interaction scenario, and many in the hypertension audience take aspirin, clopidogrel or an anticoagulant. The search “reishi, warfarin, bleeding, interaction” — zero. “Reishi, bleeding, adverse event” — zero. What was measured in humans was never tested against the drugs people actually take. And incidentally, extracts of ordinary culinary mushrooms also inhibited platelets in vitro as strongly as aspirin and more — this is not a property unique to reishi.

Hypotension and dizziness. No trial measured hypotension as an adverse event. What there is: a cross-sectional survey of 1,374 cancer patients taking reishi, in which 9.1% reported adverse effects — dry mouth 5%, constipation 4%, insomnia 3%, itching 3%, and dizziness 3%. A self-reported survey, with no control group; but 3% dizziness in an audience taking blood-pressure drugs is a number worth knowing.

And “potassium-rich mushrooms.” A dose-response meta-analysis of 32 randomized trials of potassium supplementation found a U-shaped relationship: the pressure-lowering effect weakens above a difference of 30 mmol a day, and blood pressure begins to rise above about 80. And the critical sentence: the rise was observed in participants with hypertension treated with drugs — not in the untreated. Nobody has measured potassium from mushroom supplements; but the claim “potassium, therefore good for blood pressure” can flip precisely in the person reading this page. Everything converges on one point: if you take a blood-pressure drug, an antiplatelet or an anticoagulant — every supplement, including ours, goes through your doctor. For the full list: drug interactions and who shouldn’t take reishi.

Blood pressure does not stand alone — what about cholesterol, sugar, the kidneys and the liver?

The same trials that measured blood pressure also measured lipids and sugar — and in the Cochrane review they did not move either. The only cordyceps figure comes from the kidney world. The reports of liver toxicity from reishi, as a powder and combined with other substances, bear directly on anyone taking regular medication. Each condition — its own page.

Cholesterol: in the same Cochrane review, total cholesterol (−0.07 mmol per litre) and LDL did not change either — detailed on the reishi and cholesterol page. Sugar: all the Cochrane participants were type 2 diabetes patients and HbA1c did not move; what was found on insulin and HOMA-IR — on the blood sugar page. Kidneys: the only figure on cordyceps and blood pressure is really a renal figure, and the kidney page presents it in context. Liver: a 47-year-old man developed acute hepatitis after reishi powder together with alcohol, and recovered within two weeks; the authors note how little the combination of mushroom supplements with other substances has been studied. More on the liver page. The complete picture of what has and has not been measured for reishi, condition by condition, we have gathered into a single ledger of the reishi evidence. In the same series: medicinal mushrooms and prostate health and cordyceps and lung health.

What is actually evidence-based for lowering blood pressure?

The DASH diet: 30 randomized trials, 5,545 participants, a reduction of 3.2 mmHg systolic and 2.5 diastolic, at moderate quality of evidence by GRADE. Potassium at a measured dose (up to 60 mmol a day): a reduction of 2.34 mmHg. Mushrooms are not part of any of these interventions. The address is a doctor, not a supplement.

We will not recommend a drug and will not set a dose — that is not our job. The numbers above show what real evidence looks like: the DASH diet was tested in 30 randomized trials in 5,545 participants, with and without hypertension; magnesium at up to 360 mg a day lowered blood pressure by 3.03 mmHg, and beyond three months — 4.31. And the background that explains why this matters: a consistent 2 mmHg reduction in systolic pressure across the general population translates into a significant reduction in deaths from heart disease and stroke. That is the standard. No mushroom preparation has ever tried to meet it in a hypertension group.

What has never been tested at all?

17 queries returned zero results across all of PubMed. Among them: reishi with “essential hypertension”; lion’s mane, turkey tail or cordyceps with hypertension in a double-blind trial; a medicinal mushroom with “antihypertensive treatment” in a clinical trial; reishi with warfarin; reishi with cytochrome P450; and not one study that checked whether a mushroom supplement’s label matches what is inside it.

Evidence of absence is evidence when the search is systematic. There is no publication whose title carries “blood pressure” and mentions lion’s mane or turkey tail. There is no study of vasorelaxation and nitric oxide from reishi in an aortic ring — that is, the second mechanism always quoted, after ACE, has never been tested. There is no study of cordycepin and blood pressure in the rat, none on tremella, and no prospective cohort study of mushroom consumption and blood pressure in adults. And the three queries most worth knowing about returned zero: there is no study in all of PubMed that checked whether the contents of a mushroom supplement match its label — not for beta-glucan, not for species identity. Which means that whoever writes “the supplements on the market are poor quality” has not measured either. What can be done is to publish a test of the specific product, and that is what the next chapter does. All the sources, sorted by mushroom, are also in the research hub — reishi.

What we actually measure in our bottle

After a whole page that says “did not fall” and “not tested,” you deserve to know what was measured — and about what. We grow the mushrooms ourselves, on our farm in the Galilee: fresh fruiting body, not mycelium grown on grain and not an imported powder whose name on the sack cannot be verified. The mushroom goes from harvest straight into extraction, with no drying step in between; as far as we know, we are among the few in the world who work this way. The extraction is triple, and its alcohol stage runs 7 weeks. Extraction ratios on a fresh-mushroom basis: reishi 1:3 and cordyceps 1:2.5. Alcohol in the finished extract: 32%.

And the numbers are not ours to set. We sent the finished extracts to be tested at TÜV Austria, and what came back is the beta-glucan percentage on a dry basis — and alongside it alpha-glucan, meaning starch, which was not detected in any of them. Alpha-glucan not detected is the chemical proof that there is no grain in the bottle. To understand why that matters, it helps to know the market’s three-step ladder: mycelium grown on grain, where beta-glucan is usually below 7% and most of the weight is the grain’s starch; imported dried fruiting body, whose quality depends on who dried it and when; and fresh fruiting body from the farm, which is what we do. And on a page that is entirely about “what was measured,” this deserves saying too: there is no study in all of PubMed that checked label-to-content agreement in mushroom supplements — so the only way to know what is in the bottle is an open test of the bottle. Why beta-glucan and not “total polysaccharides” — we explained separately.

All our tests are public, and anyone who wants to read the report themselves will find our guide to how to read a COA. Kosher — Mateh Yehuda Rabbinate, Rabbi Gad Atias. That is what we know how to measure and prove about what is in the bottle. What it will do for your blood pressure was not measured — so it is not written.

What this page does not say — and what we do not claim

We do not claim that reishi, cordyceps, lion’s mane or turkey tail lower blood pressure, “balance” it, prevent hypertension or replace a drug — at any dose and in any form. We do not claim that ACE inhibition in a dish or a blood-pressure drop in a rat is a clinical achievement; in humans, when it was measured, blood pressure did not move. We do not claim that the cordyceps number applies to anyone who is not a diabetic kidney disease patient taking an ACEI/ARB drug. And we do not claim the opposite either — there is no trial showing that reishi raises blood pressure in a human; what exists is one animal model with cordyceps, and a large data void. What we do say: anyone dealing with hypertension needs a doctor and a treatment with evidence behind it, and anyone taking a blood-pressure drug, an antiplatelet or an anticoagulant needs to talk to their doctor before any supplement, including ours. We sell mushroom extracts, and we are telling you explicitly not to buy them for blood pressure.

The bottom line

Medicinal mushrooms did not lower blood pressure when it was measured in humans. Reishi — the mushroom the entire claim rests on — was tested in a Cochrane review, in a meta-analysis of 17 trials in 971 participants, and in a trial in borderline blood pressure, and in all of them blood pressure did not move. The myth rolls on from a 1985 Japanese publication with no abstract, and from rats and dishes. The only number on cordyceps is from kidney patients on a drug. On lion’s mane there is no measurement. And what was measured in humans — platelet inhibition of 31.49% after two weeks — is a reason to talk to your doctor, not a reason to buy. And if someone is selling you a mushroom for blood pressure, send them this page.

Frequently asked questions

Does reishi lower blood pressure?

No, according to what has been measured in humans. The Cochrane review (5 trials, 398 participants) and the 2025 meta-analysis (17 trials, 971 participants) found no significant difference in blood pressure versus placebo, and the only trial that recruited people with borderline blood pressure (26 participants, 12 weeks) found no change either. The claim rests on rats and on enzyme inhibition in a dish.

I read about a Japanese study that proved reishi works against hypertension. What about it?

It is a 1985 publication, in Japanese, with no abstract available on PubMed and not classified as a randomized or clinical trial. Participant numbers, dose and result cannot be known from it. It has not been replicated since, and every controlled trial done after it — 971 participants in the latest meta-analysis — found no effect on blood pressure. It is the source of the myth, not evidence.

Reishi inhibits ACE like blood-pressure drugs do — doesn’t that mean it works?

No. ACE inhibition was measured in a laboratory dish (an IC₅₀ of 1.134 mg per ml for the crude extract) and in peptides isolated from fermented mycelium, not in a human body. Inhibiting an enzyme at a given concentration in a dish does not show that after swallowing, the substance is absorbed and reaches the blood vessels in sufficient quantity. That step was tested in humans — and blood pressure did not fall.

Does cordyceps lower blood pressure?

Not tested in people with hypertension. The only number that exists — a reduction of 4.57 mmHg systolic and 3.96 diastolic — is from 51 trials in diabetic kidney disease patients who were already taking an ACEI/ARB drug, with cordyceps given as an add-on to the drug. And in one rat model, cordyceps actually raised diastolic blood pressure. The direct search for cordyceps and blood pressure in humans returns zero.

I take a blood-pressure drug. Can I take reishi alongside it?

That is a question for your doctor, and what matters to know before the conversation: there is not one interaction study in all of PubMed between reishi and beta-blockers, ACE inhibitors or calcium-channel blockers. The five publications that mention these drugs alongside reishi describe them as background treatment, not as a research question. The absence of a study is not proof of safety — it is a data void.

I am on aspirin or an anticoagulant. Is that a problem?

This is the strongest human finding in the whole subject, so yes — there is something to tell your doctor. In 33 patients, reishi 3 grams a day for two weeks inhibited platelet aggregation by 31.49%. The mechanism is known, and the effect adds to that of other agents. There is no interaction study with warfarin or with antiplatelets. Tell your doctor about every supplement, including ours.

Mushrooms are rich in potassium — so are they good for blood pressure?

No study has measured that in mushroom supplements. And what has been measured on potassium matters precisely to you: in a meta-analysis of 32 trials, potassium at a measured dose lowers blood pressure, but above a difference of about 80 mmol a day blood pressure begins to rise — and that rise was observed in patients on hypertension drugs, not in untreated people. “Rich in potassium” is not an argument in favour.

If not mushrooms, what has been proven to lower blood pressure?

The DASH diet — 30 randomized trials, 5,545 participants, a reduction of 3.2 mmHg systolic and 2.5 diastolic; and potassium and magnesium at a measured dose, with reductions of 2–3 mmHg. A consistent 2 mmHg reduction across a population translates into fewer deaths from heart disease and stroke. Mushrooms are not part of any of these interventions. The first step: a doctor.

Scientific sources (peer-reviewed)

• Cochrane review: 5 trials, 398 participants; 3 trials (157 participants), reishi 1.4–3 grams a day, 12–16 weeks, all type 2 diabetes patients. No significant difference in blood pressure, HbA1c, cholesterol, LDL or BMI; adverse events 1.67 times more likely — Klupp NL, et al. Cochrane Database of Systematic Reviews, 2015. View on PubMed
• GRADE-assessed meta-analysis: 17 randomized trials, 971 participants, 200–11,200 mg a day. Reductions in BMI (−0.43) and heart rate (−3.92); no effect on blood pressure, glucose, lipids or liver enzymes. Very low quality of evidence — Jafari A, et al. Food Science & Nutrition, 2025. View on PubMed
• Randomized double-blind crossover trial in 26 patients with borderline blood pressure or cholesterol: 1.44 grams of reishi a day, 12 weeks. No change in BMI or blood pressure; insulin and HOMA-IR lower; carry-over effects — Chu TTW, et al. The British Journal of Nutrition, 2012. View on PubMed
• Randomized crossover trial in 42 healthy volunteers, 225 mg of reishi, six months: oxidation markers and liver enzymes. Hypertension mentioned only in the opening sentence; blood pressure not measured — Chiu HF, et al. Pharmaceutical Biology, 2017. View on PubMed
• The source of the myth: a 1985 Japanese publication on reishi and hypertension. No abstract available; classified as an article, not a randomized or clinical trial. No participants, dose or result to quote from it — Kanmatsuse K, et al. Yakugaku Zasshi, 1985. View on PubMed
• A review that writes triterpenoids from reishi “have been reported” to be antihypertensive — with no citation, dose or experimental system — Boh B, et al. Biotechnology Annual Review, 2007. View on PubMed
• A review of herbal drugs in cardiovascular disease that lists reishi among those “known” for cardiovascular treatment, and calls for further research on the mechanism. A mention in a list, not evidence — Kaur A, Kumar R. Current Cardiology Reviews, 2025. View on PubMed
• A comprehensive review of lion’s mane that lists “antihypertensive” among its properties — with not one blood-pressure measurement, in any system — Friedman M. Journal of Agricultural and Food Chemistry, 2015. View on PubMed
• The classic animal model: reishi in the diet of SHR rats. The only publication the direct search returns, and no abstract available — no number from it to quote — Kabir Y, et al. Journal of Nutritional Science and Vitaminology, 1988. View on PubMed
• Reishi mycelium extract in rabbits and anaesthetized rats, given parenterally: dose-dependent fall in blood pressure with no fall in heart rate, with inhibition of sympathetic activity. An anaesthetized animal, not a capsule — Lee SY, Rhee HM. Chemical & Pharmaceutical Bulletin, 1990. View on PubMed
• Intragastric reishi in ISIAH rats, seven weeks: blood-pressure reduction “at a level similar to losartan,” with increased cerebral blood flow. Rats; no mmHg number in the abstract — Shevelev OB, et al. Phytomedicine, 2018. View on PubMed
• Protein fractions from reishi mycelium inhibited ACE in vitro: IC₅₀ of 1.134 mg per ml for the crude extract, and purified fractions below 200 micrograms per ml. Test tube only — Mohamad Ansor N, et al. BMC Complementary and Alternative Medicine, 2013. View on PubMed
• Three ACE-inhibiting peptides from reishi mycelium; QLVP with an IC₅₀ of 127.9 micromoles per litre, activated eNOS phosphorylation in cultured endothelial cells. Isolated peptides, cells in a dish — Wu Q, et al. Journal of Agricultural and Food Chemistry, 2019. View on PubMed
• Meta-analysis of 51 randomized trials (3,955 participants): a cordyceps preparation as an add-on to ACEI/ARB in diabetic kidney disease patients — systolic −4.57 mmHg (95% CI: −6.78 to −2.37), diastolic −3.96 (−5.73 to −2.19). Trials mostly from Chinese databases — Li Y, Xu G. Journal of Renal Nutrition, 2020. View on PubMed
• Second meta-analysis: 38 randomized trials, 3,167 diabetic kidney disease patients, cordyceps as an add-on to ACEI/ARB. Blood pressure mentioned only as “improved,” with no number — Yan G, et al. Phytomedicine, 2023. View on PubMed
• The opposite finding: fermented cordyceps (0.75, 1.5 and 3 grams per kg) in rats with doxorubicin-induced cardiotoxicity improved cardiac indices — and raised diastolic blood pressure and mean arterial pressure — Wu R, et al. Molecular Medicine Reports, 2018. View on PubMed
• Review of the anti-thrombotic effect of cordyceps: blood viscosity, platelet aggregation and anticoagulant activity. The interaction axis for cordyceps is with anticoagulants — Li XG, Xiao JH. Zhongguo Zhong Yao Za Zhi, 2013. View on PubMed
• The only publication that measured blood pressure under turkey tail: 40 Wistar rats with metabolic syndrome, heteropolysaccharides at 300, 200 or 100 mg per kg, four weeks; the high and medium doses lowered blood pressure (P<0.05). No mmHg number — Nikolic M, et al. Pharmaceuticals, 2023. View on PubMed
• The study mistakenly cited as if it were about reishi: SHR rats with 5% shiitake or maitake powder in the diet, nine weeks — blood pressure fell — Kabir Y, et al. Journal of Nutritional Science and Vitaminology, 1987. View on PubMed
• SHR rats fed pellets with 10% agaricus from 6 to 11 weeks of age: blood pressure and heart rate significantly lower throughout the follow-up — Tsubone H, et al. Journal of Medicinal Food, 2014. View on PubMed
• Randomized double-blind placebo-controlled trial in 57 older women: agaricus extract 900 mg a day (28) versus placebo (29), 60 days, with blood-pressure measurement. “No change from baseline was found in any parameter” — Lima CUJO, et al. Scandinavian Journal of Immunology, 2012. View on PubMed
• Randomized trial in 60 adults: a Mediterranean diet with 84 grams of mushrooms a day versus the same diet without mushrooms, eight weeks. Improved fasting glucose (−2.9 versus 0.6 mg per dL; P=0.034) and nothing else — Uffelman CN, et al. The Journal of Nutrition, 2024. View on PubMed
• Systematic review of 22 papers on mushroom consumption and cardiometabolic risk factors: blood pressure rated “inconsistent”; most papers “poor” — Uffelman CN, et al. Nutrients, 2023. View on PubMed
• Systematic review: 7 prospective studies; “it has not yet been unequivocally demonstrated that culinary mushroom consumption affects cardiovascular risk factors” — Krittanawong C, et al. The American Journal of Medicine, 2021. View on PubMed
• 33 atherosclerotic patients: reishi 1 gram three times a day, two weeks — inhibition of ADP-induced platelet aggregation 31.49% (P<0.01); extracorporeal thrombus length fell from 30.05 to 20.4 mm. The strongest human finding, in the direction of bleeding — Tao J, Feng KY. Journal of Tongji Medical University, 1990. View on PubMed
• Ganodermic acid S in human platelets: 2 micromolar inhibited 50% of aggregation; 7.5 micromolar — over 95%. The molecular mechanism — Su CY, et al. Biochemical Pharmacology, 1999. View on PubMed
• The same compound amplified the PGE1-induced cAMP rise in platelets up to 1.8-fold — the effect adds to that of other agents — Su C, et al. Thrombosis Research, 2000. View on PubMed
• Extracts of eight culinary mushrooms versus aspirin in vitro: two extracts outperformed aspirin in inhibiting ADP-induced aggregation. Not a property unique to reishi — Poniedziałek B, et al. Nutrients, 2019. View on PubMed
• 14 nephrotic-syndrome patients on an ACE inhibitor, an angiotensin-receptor blocker, a calcium-channel blocker and an antiplatelet received reishi. The only place reishi was given alongside blood-pressure drugs — and blood pressure was not measured — Futrakul N, et al. Clinical Hemorheology and Microcirculation, 2004. View on PubMed
• Cross-sectional survey of 1,374 cancer patients taking reishi: 9.1% reported adverse effects — dry mouth 5%, constipation 4%, insomnia 3%, itching 3%, dizziness 3%. No control group — Li X, et al. Integrative Medicine Research, 2024. View on PubMed
• Case report: a 47-year-old man with acute hepatitis after reishi powder together with alcohol; recovery within two weeks — Guedikian R, et al. Cureus, 2023. View on PubMed
• Dose-response meta-analysis of 32 trials of potassium supplementation: a U-shaped relationship — blood pressure rises above a difference of about 80 mmol a day, and the rise was observed in patients on hypertension drugs — Filippini T, et al. Journal of the American Heart Association, 2020. View on PubMed
• The DASH diet: 30 randomized trials, 5,545 participants — a reduction of 3.2 mmHg systolic and 2.5 diastolic; moderate quality of evidence by GRADE — Filippou CD, et al. Advances in Nutrition, 2020. View on PubMed
• Potassium up to 60 mmol a day lowered systolic pressure by 2.34 mmHg; magnesium up to 360 mg — 3.03, and beyond 3 months — 4.31. A 2 mmHg reduction translates into lower mortality — Behers BJ, et al. Nutrients, 2024. View on PubMed

Read next

• Medicinal mushrooms by goal — the hub
• The research hub — reishi
• Medicinal mushrooms and heart health
• Reishi and cholesterol — what was measured
• Medicinal mushrooms and blood sugar
• Medicinal mushrooms and kidney health
• Medicinal mushrooms and the liver
• Medicinal mushrooms and prostate health
• Cordyceps and lung health
• Medicinal mushrooms and autoimmune disease
• Medicinal mushrooms and gout
• Who shouldn’t take reishi
• Who shouldn’t take cordyceps
• Drug interactions
• Do medicinal mushrooms have side effects?
• Reishi science — what was measured and what was not
• Lab results — beta-glucan
• How to read a test report (COA)

This page is educational and does not constitute medical advice, diagnosis, or a substitute for professional care. Medicinal mushroom extracts are dietary supplements, not drugs, and are not intended for the treatment of hypertension or any other medical condition. Hypertension requires medical monitoring and treatment; do not stop, replace or change the dose of a blood-pressure medication without your treating physician’s guidance. Before starting any supplement — and especially if you take blood-pressure drugs, antiplatelets or anticoagulants, are pregnant or breastfeeding, have surgery planned, have kidney or liver disease, or have any existing medical condition — consult a physician. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.*