1How these mushrooms are sold

To see how these four mushrooms are sold, we searched Amazon.co.uk for each of them on 30 September 2026 and read the product titles on the first page of results. The table shows how many products we found in each format.

The four mushrooms are not sold in the same way. Lion's mane is mostly sold as tablets, capsules and gummies, and the titles advertise a strength in milligrams. Reishi is sold as capsules and also in drinks. Cordyceps appears mostly in blends with other mushrooms. Chaga is different from the other three, because it is collected wild and is often sold as chunks or powder for making tea.

Only about 15 of the roughly 165 products print a figure for polysaccharides or beta-glucans in the title, and those figures run from 2 % to 58 %. Some titles say "polysaccharides" and others say "beta-glucans". These two words do not mean the same thing, as section 4 explains.

This count has limits. It covers one page of results for each mushroom, as shown to a buyer in Finland, and we read the titles and not the labels. We also counted by hand, so a figure may be off by one or two.

There is no single "mushroom supplement". The tests that make sense depend on the format of the product.

2What vendors test and publish

Some vendors publish the laboratory results for their mushroom products on their websites. We read the results that two of them publish: a UK brand, and an EU supplier of lion's mane extract.

The UK brand publishes a certificate for every batch. Its certificates cover the two glucans, heavy metals, pesticides, microbiology, mould toxins, PAH compounds, and allergens and gluten.

The EU supplier publishes a sample certificate for its extract. It shows four heavy metals, a microbiology panel with total count, yeasts, moulds, E. coli, staphylococci and Salmonella, and a screen of 716 pesticides.

Heavy metals, pesticides and microbiology appear in both. The UK brand adds mould toxins, PAH and the two glucans. Two vendors are not a survey of the market, but they show what a published set of results contains. The next section explains each of these tests.

3The tests, one by one

Each test below is described in the same way: what it measures, why it matters for a mushroom product, and what the law says. The name in quotation marks at the end is the package on our mushroom testing page.

Heavy metals

This test measures lead, cadmium, mercury and arsenic. A mushroom absorbs metals from whatever it grows on, so the metal content of a product depends on where and how the mushroom was grown or collected.

For a food supplement, EU law sets limits of 3.0 mg/kg for lead, 1.0 mg/kg for cadmium and 0.10 mg/kg for mercury. It sets no limit for arsenic in supplements.

We looked at these four mushrooms in detail in Part 7 of our Heavy Metals series, which explains which metal to watch in cultivated mushrooms, in wild cordyceps and in chaga.

On our mushroom page this test is "Heavy metals in this mushroom" (MSH-01).

Pesticide residues

This test is a screen: in one run, the laboratory looks for several hundred pesticides and reports each one it finds, with its concentration. Pesticides can reach a mushroom through the material it is grown on or through treatment of the crop.

EU law sets a limit for each pesticide in cultivated mushrooms and in wild mushrooms, and where it sets no specific limit, a default limit of 0.01 mg/kg applies. These limits are written for the fresh mushroom. For a dried powder or an extract they are adjusted, because drying and extraction concentrate whatever was in the fresh mushroom.

For this reason, the sample to test is the powder or extract that you sell, not the fresh mushroom.

On our mushroom page this test is "Pesticide residues" (MSH-08).

Microbiological quality

This test counts the bacteria, yeasts and moulds in the product, and it checks for E. coli, staphylococci and Salmonella. It shows whether a dried powder has been produced and stored cleanly.

EU law sets microbiological limits for certain named foods, so for many products there is no legal limit to compare these counts with. In that case the result is compared with guideline values, for example the ones your retailer or your customer uses.

This is why the report should give the actual counts, and not only the word "pass". A count can be compared with any guideline, but a "pass" refers only to the one guideline that the laboratory used.

There is one exception. EU law sets limits for the bacterium Listeria monocytogenes in ready-to-eat foods. For foods in which the bacterium cannot grow, the limit is 100 cfu/g. The regulation places a product in that group when its water activity is 0.92 or lower.

This package does not include Listeria. If you need it, tell us, and we will say whether we can add it.

On our mushroom page this test is "Microbiological quality" (MSH-02). If you need heavy metals and microbiology for the same batch, the two are combined in "Batch release" (MSH-03).

Mould toxins

This test measures aflatoxins and ochratoxin A, which are poisons that some moulds produce. Moulds can grow on mushroom material while it is being dried or while it is in storage, and the toxins stay in the material even after the mould itself has died.

That is why a clean microbiology result is not enough. It shows that little mould is alive today, but it cannot show whether an earlier mould left toxins behind.

EU law sets limits for these toxins in foods such as nuts, dried fruit, coffee and spices. It sets none for mushrooms or for food supplements. Even so, vendors include this test in the results they publish.

On our mushroom page this test is "Mould toxins" (MSH-07).

PAH, the contaminants from drying

PAH is short for polycyclic aromatic hydrocarbons, a group of compounds that form in smoke. They can get into a product when the material is dried with smoke or over direct heat, which is why this test is also described as a test for contaminants from drying. It measures four of these compounds, one of which is benzo(a)pyrene.

For this test, mushroom supplements do have a legal limit. The limit applies to food supplements that contain botanicals, and the regulation's definition of botanicals includes fungi, powders, tinctures and extracts. It is 10.0 µg/kg for benzo(a)pyrene and 50.0 µg/kg for the four compounds together. It does not apply to supplements that contain vegetable oils.

On our mushroom page this test is "Contaminants from drying" (MSH-11).

Moisture and water activity

This test measures how much water the product contains, and how much of that water is available to moulds and bacteria. It tells you whether a powder is dry enough to be stored without going mouldy.

On our mushroom page this test is "Will it keep?" (MSH-09).

Radioactivity in wild mushrooms

This test measures radioactive caesium, which is still present in forests in some regions after the Chernobyl accident. Wild mushrooms take it up, so the test matters for material collected in the wild and not for cultivated mushrooms. Of the four mushrooms in this article, this means chaga.

EU law sets a limit of 600 Bq/kg of caesium-137 for food that comes from thirteen countries outside the EU, among them Russia, Belarus, Ukraine, Turkey, Switzerland and Great Britain. The limit therefore applies to chaga from any of those countries. For a dried product, the level is calculated for the product as prepared for consumption.

The same regulation requires an official certificate at the border for wild mushrooms, including dried mushrooms in powder. It does not name chaga, so whether a consignment of chaga needs that certificate depends on its customs code. The regulation does not cover mushrooms collected inside the EU.

On our mushroom page, "Radioactivity in wild mushrooms" (MSH-05) measures caesium-137, caesium-134 and iodine-131. A wider screen is available as "Radioactivity, full gamma screen" (MSH-06).

Two narrower tests

Two further tests answer narrower questions. "Protein content against the label" (MSH-10) measures the protein in a product, which is useful if your label states a protein figure.

"Is it free from animal material?" (MSH-12) looks for the DNA of specific animal species, and it supports a vegan statement. It shows that the species tested are absent, but it does not tell you which mushroom is in the product.

4Beta-glucan and alpha-glucan

Beta-glucan is the figure that some vendors print on the label, so this test needs a longer explanation.

Glucans are long chains of glucose, and there are two kinds. Beta-glucan is part of the cell wall of the mushroom. Alpha-glucan is the kind of glucan that starch is made of.

Both kinds are polysaccharides, and this is the reason a "polysaccharides" figure can mislead. The common methods for total polysaccharides cannot tell beta-glucan from starch. So a label that says "30 % polysaccharides" does not tell you how much beta-glucan the product contains.

Two published studies show what to expect. The first is a university study of 39 species of whole dried mushrooms. It found that beta-glucan varies widely from one species to another, from 7.8 g per 100 g of dry mass in the cap of one wild bolete to 60.8 g in turkey tail. Alpha-glucan was low in the cultivated species, between 0.8 and 4.6 g per 100 g.

The second study was carried out by the maker of a test kit, and it covers the four mushrooms of this article. It measured each sample with two methods, an older one and a refined one, and it also measured several commercial products.

The figures are percentages of the sample as received, and the study does not name the products.

How to read a glucan result

The simplest way to read a glucan result is to compare it with the whole mushroom of the same species. A product that is mostly mushroom contains about as much beta-glucan as the mushroom itself, and little alpha-glucan. A product that has been diluted with grain, fillers or sweeteners contains much less beta-glucan, and usually much more alpha-glucan.

The study gives one clear example of each.

A product that is mostly mushroom shows a beta-glucan figure close to that of the whole mushroom, with a low alpha-glucan figure. A diluted product shows the reverse. In this study, whole lion's mane and whole reishi contained 44 % and 51 % beta-glucan. A lion's mane or reishi product near those values is close to the whole mushroom, and a product below 10 % is far from it.

Two of the four mushrooms need a different reading.

• Cordyceps. The whole mushroom contained only 11 % beta-glucan and about 25 % alpha-glucan. The alpha-glucan is high because cordyceps naturally contains 20 to 25 % of a sugar called trehalose, which this method counts as alpha-glucan. So for cordyceps, a beta-glucan figure near 11 % is what the whole mushroom gives, and a high alpha-glucan figure does not mean that grain was added.
• Chaga. The whole material contained 18.5 % of glucan in total, so its beta-glucan must be lower still. A chaga product will therefore show a much lower beta-glucan figure than a lion's mane or reishi product, even when it is all chaga.

Why the method matters

These reference values were obtained with one method, and another method gives other numbers. The same cordyceps sample gave 27.70 % beta-glucan with the older method and 11.15 % with the refined one, and the study states that the two methods are not equivalent.

This means that a product can only be compared with a reference that was measured in the same way. If you want to compare your batch with your supplier's certificate, have both measured in the same laboratory with the same method.

Where the alpha-glucan in a product comes from

When a lion's mane or reishi product shows a lot of alpha-glucan, the study names three possible sources. Some products are made from mycelium grown on rice, oats or sorghum, and the grain cannot be separated from the product. Some contain fillers such as rice powder or maltodextrin. And some contain sweeteners: the gummy in the study was about 40 % maltitol.

For a vendor, the test answers practical questions: which beta-glucan figure can go on the label, whether a supplier's "polysaccharides" figure consists of beta-glucan or of starch and fillers, and whether the finished product still contains what the raw extract contained.

On our mushroom page this test is "Beta-glucan and alpha-glucan" (MSH-04). It reports the two glucans as two separate figures.

5What this means for each product format

The formats described in section 1 call for different tests.

A powder or capsule made from one mushroom extract

This is the simplest case. The tests that vendors publish for it include heavy metals, pesticides and microbiology, which on our page are "Batch release" (MSH-03) and "Pesticide residues" (MSH-08). If your label prints a glucan figure, "Beta-glucan and alpha-glucan" (MSH-04) is the test that supports it.

A blend of several mushrooms, or of a mushroom with vitamins and botanicals

The contaminant tests are the same, and they are done on the finished product. A glucan figure is less informative here, because it describes the whole blend and cannot be assigned to any one of the mushrooms in it.

Gummies and drops

Sweeteners and carriers interfere with the glucan measurement, as the gummy in section 4 showed. If you want the glucan test for a gummy or a liquid, tell us the recipe first, and we will tell you whether the test suits the product. The contaminant tests can be done as for any other format.

Coffee, tea and drink blends

In these products the mushroom is one ingredient among several, so the contaminant tests are done on the finished product. The other ingredients have legal limits of their own: for ochratoxin A, the limits are 3.0 µg/kg for roasted coffee, 5.0 µg/kg for soluble coffee and 3.0 µg/kg for cocoa powder.

Wild chaga, sold as chunks or powder

Because chaga is collected wild, the two tests that matter most are "Heavy metals in this mushroom" (MSH-01) and "Radioactivity in wild mushrooms" (MSH-05).

Whatever the format, test the product in the form in which you sell it.

6One table to keep

How to read a laboratory report, including the reporting limit and the measurement uncertainty, is explained in Part 3 of the Heavy Metals series. The tests and their prices are on the mushroom testing page.