Mushroom Capsules and Tablets: What a Label Can Tell You

A capsule or tablet is the most common way mushroom supplements are sold. The label is the only information most buyers have, so it helps to know what it must show and what it leaves out.

What the label must show

The FDA says a dietary supplement label must carry a Supplement Facts panel that lists the serving size and number of servings per container and declares each dietary ingredient. Except for ingredients inside a proprietary blend, the amount per serving must be given. [1] The label must also list "other ingredients" not in the panel, which the FDA says include fillers, binders, excipients, preservatives, sweeteners and flavorings. [1]

For a mushroom capsule, that means you can usually find:

• the ingredient name, which may be a common name only (look for the scientific name, for example Ganoderma lucidum or Hericium erinaceus);
• the serving size, which may be more than one capsule;
• an amount per serving, unless the mushroom sits inside a "blend";
• the other ingredients, such as fillers.

What the label cannot tell you

• Whether the species is right. In an Italian laboratory study of 19 mushroom supplements sold as encapsulated powders, DNA sequencing matched the labeled species in 6 of the 19. [2] Products labeled as Ganoderma lucidum matched other Ganoderma species. [2] This is one study from 2023 on products from one market, so it shows a risk, not how common it is.
• Whether every capsule is the same. The same study found that glucan content varied between capsules from the same batch, and overall ranged from 19.15 to 60.05 g per 100 g. [2]
• Which part of the mushroom is inside. The study authors note that commercial raw materials typically consist of mycelium, which grows more quickly and is less expensive to produce. [2] See Fruiting body vs mycelium and mycelium grown on grain.
• Whether it is tested for contaminants. In that study, arsenic, cadmium, mercury and lead were below the European legal limits in the samples tested. [2] That result does not apply to other products. The FDA says its regulations require makers to follow current good manufacturing practices, but it does not approve supplements before sale. [1]

Capsules versus tablets

Both hold dry material or extract. Tablets are pressed and usually need binders; the FDA lists binders and fillers among possible other ingredients. [1] Proper evidence not found on whether one works better than the other: we searched PubMed for trials comparing capsules with tablets or powders of the same mushroom and found none.

Study amounts are not a label target

One Japanese trial gave adults aged 50 to 80 with mild cognitive impairment four 250 mg tablets, each containing 96% Hericium erinaceus dry powder, three times a day for 16 weeks (30 people in total). [3] That is what that trial did. A different product, mushroom or person cannot be matched to it from a label, and a clinician or pharmacist decides what is right for an individual.