Functional mushrooms are one of the fastest-growing categories in food and supplements. The research behind them is real but early, and the quality of products varies more than in almost any other category. Here is what to know before you choose.
Lion's mane (Hericium erinaceus)
A white, shaggy mushroom eaten as food in East Asia. Interest centers on compounds that, in laboratory and animal studies, affect nerve growth factors. In people, the evidence is small: a frequently cited Japanese trial in 2009 gave 30 older adults with mild cognitive impairment lion's mane powder for 16 weeks and found better scores on a cognitive test than placebo, which faded after they stopped. A handful of small trials since then have had mixed results.
Reishi (Ganoderma lucidum)
A woody, bitter mushroom with a long history in traditional Chinese medicine, used as a tea or extract rather than eaten. It contains triterpenes and polysaccharides that are studied for their effects on the immune system. Reviews of human research, including a Cochrane review, have found the evidence too limited to draw firm conclusions. Reishi can interact with blood thinners and blood-pressure medicines, and rare cases of liver injury have been reported with reishi powder.
Cordyceps (militaris and CS-4)
Wild Cordyceps sinensis is rare and expensive, so supplements use either cultivated Cordyceps militaris fruiting bodies or a fermented mycelium strain known as CS-4. It is best known for exercise and energy; trials of endurance and oxygen use have produced mixed results.
How to read a mushroom label
- Fruiting body or mycelium? The fruiting body is the mushroom you would recognize. "Mycelium on grain" or "myceliated grain" products are grown on oats or rice, and the finished powder can contain a lot of that grain starch.
- Beta-glucans, not "polysaccharides". A "polysaccharide" percentage can include starch. Beta-glucans measured with a specific enzymatic method tell you much more about the mushroom content.
- Extract ratio and dose. "8:1 extract" means eight parts mushroom made one part extract. It says nothing about quality on its own; the dose per serving and the lab result do.
- A certificate of analysis for identity, beta-glucans, heavy metals and microbes. Mushrooms absorb metals from where they grow.
Our view
If you are curious, treat mushrooms as a food habit with an open question attached, not as a treatment. Choose products that tell you what part of the mushroom they use and what the lab measured, and ask your doctor first if you take medication.
Sources
- Mori K et al., Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial, Phytotherapy Research, 2009.
- Jin X et al., Ganoderma lucidum (Reishi mushroom) for cancer treatment, Cochrane Database of Systematic Reviews, 2016.
This guide is general information, not medical advice. Talk to your doctor or pharmacist before starting a supplement if you are pregnant or nursing, take medication, or have a medical condition.