Medicinal Mushrooms and the Immune System: Reishi, Turkey Tail, Chaga and More

Short answer: medicinal mushrooms such as reishi, turkey tail, shiitake, chaga and lion’s mane contain beta-glucans that affect immune cells in laboratory and animal studies. Human evidence is mostly small studies with mixed results, there is no proven “best mushroom for immunity”, and they are not risk-free if you take medicines or have a chronic condition.

What medicinal mushrooms are and what beta-glucans do

“Medicinal mushrooms” are fungi used in traditional medicine, particularly in East Asia, and sold today as powders, extracts, capsules and teas. Their best-studied components are beta-glucans, complex sugars (polysaccharides) in fungal cell walls.

In laboratory and animal studies, beta-glucans bind to receptors on immune cells such as macrophages, natural killer (NK) cells and dendritic cells and change how they respond — often called “immunomodulation”. Whether this means fewer infections or better health in people has not been clearly shown.

Reishi (Ganoderma lucidum)

Reishi has a long history in Chinese medicine and is taken as an extract, powder or tea. It contains beta-glucans and triterpenes (ganoderic acids), which show anti-inflammatory and antioxidant activity in laboratory research. A few small human studies report changes in immune markers, but results are inconsistent and the evidence is weak.

Turkey tail (Trametes versicolor)

Turkey tail is among the most researched medicinal mushrooms, largely because of PSK (polysaccharide-K), a defined extract used in Japan as a prescription product alongside standard cancer treatment, under medical supervision. That is not evidence that over-the-counter turkey tail supplements treat or prevent cancer, and never a reason to self-treat or to delay medical care. For healthy people, evidence of immune benefit is limited.

Shiitake (Lentinula edodes)

Shiitake is a common culinary mushroom. It contains a beta-glucan called lentinan, studied mostly in Asia, and a few small studies of people eating shiitake report changes in immune markers — early results only. Raw or undercooked shiitake can cause an itchy rash in some people, so cook it well.

Chaga (Inonotus obliquus)

Chaga grows on birch trees in cold climates and is used in Russian folk medicine, usually as a tea. It shows antioxidant and immune effects in cell and animal studies, but human trials are very limited.

Lion’s mane (Hericium erinaceus)

Lion’s mane is studied mainly for the brain and nerves (hericenones and erinacines affect nerve growth factor in laboratory studies). It also contains beta-glucans, but its immune effects in people have not been established.

Safety: who should be careful

• Liver: liver injury has been reported with some reishi products, particularly powders. People with liver disease should ask a doctor first.

• Kidneys: chaga is high in oxalate, and kidney damage has been reported with heavy, long-term use. Avoid it with kidney disease or kidney stones unless a doctor agrees.

• Blood thinners and surgery: reishi and chaga may affect blood clotting — ask your doctor first if you take anticoagulants or have surgery planned.

• Immunosuppressants and autoimmune disease: because these mushrooms act on immune cells, do not use them without medical advice.

• Diabetes and blood pressure medicines: some mushrooms may lower blood sugar or blood pressure.

• Children, pregnancy and breastfeeding: safety has not been established, so avoid them unless a doctor advises otherwise.

How to choose a mushroom supplement

Quality varies widely, and supplements are not approved for effectiveness before sale. Check that the product:

1. Names the species (for example Ganoderma lucidum), not just “mushroom blend”.

1. States whether it uses the fruiting body or mycelium grown on grain, which can be mostly starch.

1. Lists beta-glucan content, not only “polysaccharides”.

1. Has been independently tested for contaminants such as heavy metals.

1. Makes no claims to cure, treat or prevent disease.

Eating culinary mushrooms like shiitake as part of a varied diet is a low-risk option. For traditional Korean herbal products, see our guide to Korean herbal medicine supplements.

Medicinal mushrooms and HemoHIM

HemoHIM is a different product: a liquid extract of three herbs (Angelica gigas, Cnidium officinale and peony root), not mushrooms. No study has compared it with medicinal mushrooms, so neither can be called better. In South Korea it is a registered health functional food with the approved claims that it “may help improve immune function” and “may help reduce fatigue”, based on a few small human trials. See what is HemoHIM and HemoHIM clinical studies.

Combining HemoHIM with mushroom supplements has not been studied, so extra benefit is unproven and interactions are unknown; the same cautions apply (blood thinners, immunosuppressants, autoimmune or liver disease, pregnancy). As of October 2026, HemoHIM is sold again in Atomy’s Singapore mall and, as HemoHIM G (艾多美 煥力飲G), in Atomy’s Taiwan mall; it is still not sold in Hong Kong. See HemoHIM side effects and safety, including the 2021 Hong Kong and Taiwan warnings. This site is run by an independent Atomy distributor.

Bottom line

Medicinal mushrooms act on immune cells in the laboratory, but evidence that supplements improve immunity in healthy people is limited and mixed, and some carry real risks. If you want to try one, choose a clearly labelled, independently tested product and ask your doctor or pharmacist first.