Do Mushroom Supplements Help the Immune System? What the Research Shows

Functional mushrooms have gone mainstream. Turkey tail, reishi, chaga, shiitake and maitake now show up in capsules, powders, coffees and gummies, most promising to “boost” your immune system. But do mushroom supplements actually help, and if so, which ones?

This guide explains how mushrooms interact with the immune system, what human studies have (and haven’t) shown, how the most popular immune mushrooms compare, what to look for in a supplement, and who should be careful. For a wider look at which immune supplements have the strongest evidence overall, see our guide to the best supplements for cold and flu season.

How Do Mushrooms Affect the Immune System?

The key compounds are beta-glucans: long chains of sugar molecules that form part of the mushroom’s cell wall. Your immune system has evolved to recognize them, because fungi are something it needs to detect.

Immune cells such as macrophages and dendritic cells carry a receptor called Dectin-1 that binds beta-glucans. When it does, it can trigger a range of responses, from engulfing pathogens to releasing signaling molecules (cytokines). Researchers are also studying how beta-glucans may help “train” innate immune cells to respond more effectively later on, a concept known as trained immunity (Mata-Martínez et al., 2022).

Importantly, beta-glucans are generally described as immunomodulators, not simple “boosters.” Their effects appear to depend on context, which is one reason results vary between studies. Mushrooms also contain other active compounds, including triterpenes (especially in reishi), phenolic antioxidants and sterols (Łysakowska et al., 2023).

What Does the Human Research Show?

Most mushroom research has been done in cells and animals. Human studies are fewer, but some are encouraging:

• Shiitake in healthy adults: In a randomized study, 52 healthy adults aged 21 to 41 ate 5 or 10 grams of dried shiitake daily for four weeks. Afterwards, two types of immune cells (gamma-delta T cells and NK-T cells) multiplied and activated more readily in lab tests, and levels of secretory IgA, an antibody that protects the lining of the gut and airways, went up. A marker of inflammation (CRP) went down (Dai et al., 2015).
• Fewer respiratory infections: A review of beta-glucan research concluded they may help reduce recurrent respiratory infections in children, adults and athletes (Jesenak et al., 2017). A 2025 randomized trial of 249 children with frequent infections found that adding a beta-glucan from oyster mushrooms to vitamin D and zinc cut respiratory infections by about 15% over three months, compared with vitamin D and zinc alone (Jesenak et al., 2025).

The honest limitations: the shiitake study measured immune markers, not whether people actually got sick less. The infection trials mostly involved children or one specific extract. And a 2023 review noted that long-term clinical studies are still needed to confirm the benefits, safety and ideal doses of medicinal mushrooms (Łysakowska et al., 2023). So the evidence is promising, but not yet at the level of vitamin D or probiotics.

What Is the Best Mushroom for the Immune System?

There isn’t one clear winner, because few studies compare mushrooms head to head. Here’s how the most popular immune mushrooms stack up on the evidence:

Mushroom	What’s known	Human evidence for everyday immune support
Shiitake	Rich in beta-glucans (including lentinan)	Small randomized trial in healthy adults showing improved immune cell activity
Oyster (pleuran)	Source of the beta-glucan pleuran	Randomized trials, mostly in children, showing fewer respiratory infections
Turkey tail	Contains polysaccharopeptides (PSK, PSP)	Studied mainly as purified extracts in people under medical care; limited data in healthy adults
Reishi	Beta-glucans plus triterpenes; widely used in traditional medicine	Limited in healthy people; rare case reports of liver injury with powder
Maitake	Beta-glucans (D-fraction)	Mostly laboratory and early-stage studies
Chaga	Antioxidant compounds	Mostly laboratory studies; high in oxalates

Does turkey tail boost the immune system?

Turkey tail is one of the most searched immune mushrooms, and its compounds have clear immune-modulating activity in the lab. Purified turkey tail extracts (PSK and PSP) have a long history of study, including use alongside conventional medical treatment in some countries (Jędrzejewski et al., 2023). However, that research largely involves specific pharmaceutical-grade extracts in people under medical care. There’s much less evidence on everyday turkey tail supplements for healthy adults, so it’s fair to call it promising rather than proven.

Why a blend can make sense

Because different mushrooms contain different types of beta-glucans and other compounds, and no single mushroom has decisively outperformed the rest, many formulas combine several species. A blend gives you a broader spread of compounds. The trade-off is that each individual mushroom is present in a smaller amount than in single-mushroom studies. (Some mushrooms in these blends, like lion’s mane and cordyceps, are better known for focus and energy. We compare them in Lion’s Mane vs. Cordyceps.)

How to Choose a Mushroom Supplement

• Extract vs. raw powder: beta-glucans sit inside tough cell walls. Hot-water extraction helps release them, so “extract” usually delivers more of the active compounds than plain ground mushroom.
• Fruiting body vs. mycelium: the fruiting body is the mushroom you can see; mycelium is the root-like network, often grown on grain. Both are used. Look for clear labeling of which is in the product.
• Organic and tested: mushrooms absorb what’s in their growing environment, so organic cultivation and third-party testing for heavy metals matter.
• Consistency: the studies that showed benefits used mushrooms daily for weeks to months. Pick something you’ll take every day.

Mushroom Supplement Side Effects and Who Should Be Careful

For most healthy adults, culinary-type mushroom supplements are well tolerated. The most common side effects are mild digestive upset, such as bloating or loose stools, especially when starting. But there are some real cautions:

• Reishi and the liver: there are rare case reports of liver injury linked to reishi powder, including one in combination with alcohol (Guedikian et al., 2023). Stop and see a doctor if you notice yellowing skin or eyes, dark urine or upper-right abdominal pain.
• Immune-suppressing medication or autoimmune conditions: because mushrooms act on the immune system, check with your doctor first if you’ve had an organ transplant, take immunosuppressants, or have an autoimmune disease.
• Blood thinners and upcoming surgery: some mushrooms, including reishi, may affect blood clotting. Stop about two weeks before surgery and ask your doctor if you take anticoagulants.
• Diabetes medication: some mushrooms may lower blood sugar, so monitor your levels.
• Kidney stones: chaga is naturally high in oxalates. If you’re prone to kidney stones, check with your doctor.
• Mushroom allergy, pregnancy and breastfeeding: avoid if you’re allergic to mushrooms or mold, and check with your provider if you’re pregnant or nursing.

Mushroom Supplements vs. Mushroom Coffee

Mushroom coffees and teas are a popular way to get mushrooms, but they usually contain much smaller amounts than a dedicated supplement, and doses are rarely standardized. They can be a pleasant habit; just don’t expect them to match the amounts used in research.

Frequently Asked Questions

Do mushroom supplements really help the immune system?

They can support it. Beta-glucans from mushrooms interact with immune cells, and small human trials show improved immune cell activity and, in some groups, fewer respiratory infections. The evidence is still early, so they’re best used alongside proven basics.

How long do mushroom supplements take to work?

In studies, changes in immune markers appeared after about four weeks of daily use, and infection-prevention trials ran for around three months. Start before cold and flu season and take them consistently.

Can I take mushroom supplements every day?

Yes, most healthy adults can take them daily. Research has used daily intake for weeks to months. Check with your doctor if any of the cautions above apply to you.

When is the best time to take mushroom supplements?

Any time of day works. Taking them with food can reduce digestive upset. Consistency matters more than timing.

Can I take mushroom supplements with vitamin D and zinc?

Yes. There are no known interactions between them, and the 2025 children’s trial actually combined a mushroom beta-glucan with vitamin D and zinc. For more on pairing vitamin D and zinc, see Can You Take Vitamin D and Zinc Together?

Can mushroom supplements cause heart palpitations?

This isn’t a commonly reported side effect of immune mushrooms. If you notice palpitations, check whether your product also contains caffeine (common in mushroom coffees and some “energy” blends), stop taking it, and speak with your doctor.

The Bottom Line

Mushroom supplements are one of the more interesting areas of immune research. Their beta-glucans genuinely interact with immune cells, and early human trials are encouraging. But the evidence is still developing, so the smartest approach is to treat mushrooms as a supportive layer on top of the foundations that are better proven: vitamin D, a good diet, sleep, movement, and your annual flu shot. Choose a quality extract, take it daily, and give it several weeks.

References

1. Mata-Martínez P, Bergón-Gutiérrez M, del Fresno C. Dectin-1 signaling update: new perspectives for trained immunity. Front Immunol. 2022;13:812148. doi:10.3389/fimmu.2022.812148
2. Łysakowska P, Sobota A, Wirkijowska A. Medicinal mushrooms: their bioactive components, nutritional value and application in functional food production. A review. Molecules. 2023;28(14):5393. doi:10.3390/molecules28145393
3. Dai X, et al. Consuming Lentinula edodes (shiitake) mushrooms daily improves human immunity: a randomized dietary intervention in healthy young adults. J Am Coll Nutr. 2015;34(6):478-487. doi:10.1080/07315724.2014.950391
4. Jesenak M, Urbancikova I, Banovcin P. Respiratory tract infections and the role of biologically active polysaccharides in their management and prevention. Nutrients. 2017;9(7):779. doi:10.3390/nu9070779
5. Jesenak M, et al. Novel chewable pleuran-based supplement decreases respiratory tract infections in children: a randomised controlled trial. Adv Ther. 2025;42(12):6132-6149. doi:10.1007/s12325-025-03393-3
6. Jędrzejewski T, et al. COVID-19 and cancer diseases: the potential of Coriolus versicolor mushroom to combat global health challenges. Int J Mol Sci. 2023;24(5):4864. doi:10.3390/ijms24054864
7. Guedikian R, et al. Ganoderma lingzhi (reishi mushroom)-induced acute liver injury in the setting of alcohol use: a case report and review of the literature. Cureus. 2023;15(9):e45953. doi:10.7759/cureus.45953

This article is for educational purposes only and is not medical advice. *These statements have not been evaluated by the Food and Drug Administration. Holitro products are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before starting a new supplement, especially if you are pregnant, nursing, taking medication, or have a medical condition.