Cordyceps vs Reishi: Key Differences

Quick answer

Cordyceps and reishi each have an early immune cell finding, of different kinds. Cordyceps raised natural killer cell activity at about 1.5 g a day. Reishi raised cell counts only as a purified beta-glucan at 200 mg a day, not as the whole mushroom. LiverTox rates reishi a possible cause of liver injury, cordyceps an unlikely one.^1,2,3,4,5

Key facts

Cordyceps raised natural killer cell activity in trials of healthy adults at about 1.5 to 1.7 g a day for 4 to 8 weeks.^1,2,6
Reishi raised some immune cell counts as a purified beta-glucan at 200 mg a day for 12 weeks. Whole reishi at 1.44 g a day for 4 weeks left immune markers largely unchanged.^3,7
When 19 reishi supplements bought in the United States were analyzed, only 5 matched their labels for triterpenes and polysaccharides.⁸
Two people in Taiwan had high blood lead from a cordyceps powder that held up to 20,000 ppm of lead.⁹

The two immune findings, compared

Cordyceps and reishi: the immune findings^1,2,3,6,7,10
	Cordyceps	Reishi
What was measured	How active natural killer cells were in blood samples	How many T cells and natural killer cells there were
What people took	A Cordyceps militaris powder, a mycelium extract and a Cordyceps militaris drink	A purified beta-glucan from reishi; whole reishi and a reishi extract in other trials
Daily amount	About 1.5 to 1.7 g in the powder and extract trials	200 mg of the purified fraction; 1.44 to 4 g of whole reishi
Length	4 to 8 weeks	12 weeks for the purified fraction; 10 days to 4 weeks for whole reishi
Trials with no change in immune measures	None among the three immune trials we read	Two small trials of whole reishi
Were illnesses counted?	No	No

What each has shown in people

The two findings are graded the same, early, and they are not the same kind of finding. One is about how active a type of immune cell was, the other about how many cells were counted.

May raise natural killer cell activity, one measure of immune function, in healthy adults; whether this means fewer illnesses was not tested*^1,2,6

Early evidence

In 79 healthy Korean men, 1.5 g a day of Cordyceps militaris for 4 weeks raised natural killer cell activity and lymphocyte growth more than placebo. In 79 healthy adults, 1.68 g a day of a cordyceps mycelium extract (Paecilomyces hepiali) for 8 weeks raised natural killer cell activity by about 39% compared with placebo. In a 40-person trial of a Cordyceps militaris drink, activity rose in men by 4 weeks against their starting level and, compared with placebo, in women by 8 weeks. The trials were small and short, and none counted illnesses.

Amount studied: 1.5 to 1.7 g a day for 4 to 8 weeks

A purified reishi beta-glucan may raise counts of some immune cells in healthy adults*^3,7,10,11

Early evidence

In a randomized, placebo-controlled trial in healthy adults aged 18 to 55 (157 enrolled, 135 finished), 200 mg a day of a purified reishi beta-glucan for 12 weeks raised counts of several kinds of T cells and natural killer cells more than placebo. It did not measure whether people fell ill less often, and a company paid for it. A trial in young children who ate a yogurt with reishi beta-glucans found a similar rise. Whole reishi did not show this: 1.44 g a day for 4 weeks, and 4 g a day of an extract for 10 days, left immune measures unchanged in small trials.

Amount studied: 200 mg a day of purified reishi beta-glucan, for 12 weeks

Neither set of trials followed people to see whether they stayed well, so both are readings from blood tests. The reishi reading also depends on which preparation was used, and the one that worked is not the one most people buy.^1,3,10

How each is grown

Reishi is a large, reddish-brown mushroom with a fan-shaped cap that grows at the base of trees or on stumps. Because it is rare in the wild, it is cultivated on logs, sawdust or wood chips.⁵

Most products sold as Cordyceps sinensis are not the wild fungus but a mycelium grown in the laboratory, such as the strain Cs-4. Some of these strains, such as Paecilomyces hepiali, are a related fungus first isolated from wild cordyceps.^2,4

Both are farmed rather than gathered, by different routes. Reishi is cultivated on logs, sawdust or wood chips and sold as the mushroom itself or as an extract of it. Cordyceps is cultured as mycelium, and the species behind the name can differ from the one on the front of the bottle.^4,5

Checking what is in the capsule

When 19 reishi supplements bought in the United States were analyzed, the measured triterpenes and polysaccharides matched the label in only 5.⁸

Cordyceps militaris is a related species that is grown commercially and costs less than wild Ophiocordyceps sinensis. It contains cordycepin: one mycelium powder used in a trial held 1,373 mg per 100 g.^6,12,13

In the sources we read, only reishi has had an analysis of this kind, and the result is a reason to read labels with care. For cordyceps we found no matching survey of products against their labels. The cordycepin figure for the one powder that was tested is that powder's own, and other products will differ.^6,8

Usual amounts

Most commercial cordyceps products are a laboratory-grown mycelium, taken at 0.5 to 4 g a day.⁴

LiverTox gives the usual amount of reishi as 500 mg to 3 g a day.⁵

The two usual ranges overlap, which makes it tempting to swap one mushroom for the other. That swap is not backed by any study, because the findings above come from different preparations and different outcomes, and no study set the two side by side.^4,5

What's in ours

In our Mushroom Complex, cordyceps and reishi each come to 266 mg a day. That is below the 500 mg low end of reishi's usual range, well below the amounts used in the cordyceps trials, and a different thing from the 200 mg of purified beta-glucan in the reishi trial, since the label gives no beta-glucan figure. We make no claim for either.^3,5,14

Liver, contamination and who should ask first

Rare cases of liver injury have been reported, usually 1 to 2 months after starting reishi, with tiredness, nausea, stomach pain, poor appetite, dark urine or yellowing of the skin and eyes. Most people recovered within 1 to 3 months of stopping, but one woman died.⁵

LiverTox rates reishi a possible rare cause of liver injury (category D) and notes that many reported cases were poorly documented, with other causes not always ruled out.⁵

Rare: hepatoportal sclerosis, a disorder of the small veins in the liver, in an 81-year-old woman who had taken a cordyceps tablet daily for 5 years. Doctors judged cordyceps a possible cause, and she improved after stopping.¹⁵

Lead poisoning from contaminated cordyceps powder: two cases in Taiwan, where the powder held up to 20,000 ppm of lead. Blood lead returned to normal after they stopped taking it.⁹

Ask your doctor first if you take medicines that suppress the immune system, for example after a transplant, or have an autoimmune condition: both mushrooms moved immune measures in trials^1,3
Ask first if you have liver disease, and stop and call a doctor if you notice dark urine, yellowing of the skin or eyes, or unusual tiredness^5,15
Ask first if you take a blood thinner or antiplatelet medicine, or have surgery planned: cordycepin slowed platelet clumping in laboratory tests, and the warfarin label asks for more frequent INR checks when any herbal product is started or stopped^16,17
Ask first if you take insulin or another medicine that lowers blood sugar^5,18
Ask first if you are pregnant or breastfeeding, under 18, or allergic to mushrooms or molds

Questions people ask

Do cordyceps and reishi do the same thing?

Not on the evidence. Each has an early finding on immune cells, but cordyceps was measured by cell activity and reishi by cell counts, and the reishi finding is for a purified extract.^1,3

Is the reishi in a mushroom blend the same as the purified beta-glucan in the trial?

No. The trial used 200 mg a day of a purified beta-glucan. Whole reishi at 1.44 g a day left the immune markers measured largely unchanged, and our Mushroom Complex lists 266 mg of reishi extract with no beta-glucan figure.^3,7

Should I ask a doctor before taking cordyceps or reishi with immune-suppressing medicines?

Yes. Both mushrooms moved immune cell measures in small trials, and no study tested them alongside medicines that suppress the immune system. A pharmacist or doctor can check your own list of medicines.^1,3

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Sources

*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.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.