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Dietary supplement

Reishi Ingredients & Drug Interactions

by Host Defense Mushrooms

Reishi label
See full label image
Powder Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Reishi against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Reishi is a dietary supplement by Host Defense Mushrooms with 1 active ingredient. Its ingredients are commonly taken for immune support, fatigue and general well-being, stress and sleep.Based on those ingredients, 375 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Reishi. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Reishi by Host Defense Mushrooms

Ask about any prescription or over-the-counter medication and we check it for interactions with Reishi by Host Defense Mushrooms — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Reishi by Host Defense Mushrooms

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Host Defense Mushrooms Reishi is a single-ingredient product: reishi mushroom (also called Ganoderma lucidum). That's the whole formula — no fillers or binders listed.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Reishi Mushroom's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: supports whole-body wellness, vitality, calm mind.
  • We looked for evidence on: Psychological well-being, Stress, Insomnia, Chronic fatigue syndrome (CFS), Cancer-related fatigue, relaxation — and 2 related terms.
  • The closest evidence on file: Reishi Mushroom is rated "Insufficient Reliable Evidence To Rate" for Chronic fatigue syndrome (CFS) (Natural Medicines).
  • Also on file: Reishi Mushroom is rated "Insufficient Reliable Evidence To Rate" for Cancer-related fatigue, Insomnia, Stress, Psychological well-being.

The evidence for reishi is patchy. For lowering cholesterol (hyperlipidemia), it appears to be possibly ineffective based on the data we hold.

For altitude sickness, Alzheimer's disease, and athletic performance, there isn't enough reliable evidence in our data to say whether it works or doesn't.

The evidence, ingredient by ingredient Reishi Mushroom

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Reishi is generally well tolerated in the short term, but long-term safety hasn't been well studied. The most common side effects are dizziness, dry mouth, itching, nausea, rash, and stomach upset.

A small number of people report respiratory allergy to reishi spores, sore throat, or runny nose; rare effects include insomnia and headache. There isn't enough safety data to recommend reishi during pregnancy or while breastfeeding.

Talk with your doctor or pharmacist if you're pregnant, planning to become pregnant, or breastfeeding.

Side effects, ingredient by ingredient Reishi Mushroom

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Reishi Mushroom.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 375 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Check your blood thinners (anticoagulants and antiplatelet drugs) before starting — higher doses of reishi may increase bleeding risk. Also double-check blood pressure medications and diabetes drugs, which could have additive effects with reishi.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Reishi may be worth considering if you're interested in immune or general wellness support, but the evidence for specific conditions is thin. If you take blood thinners, blood pressure meds, or diabetes drugs, check with your pharmacist first — especially at higher doses.

Long-term safety is still an open question.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 20, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Reishi, straight from the product label.

Brand Host Defense Mushrooms
Barcode (UPC) 633422822723
Net contents 3.5 Ounce(s); 100 Gram(s)
Market status On market
Date entered into DSLD Jun 20, 2024
DSLD ID 312250
Product type Botanical
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Organic, Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Reishi by Host Defense Mushrooms, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1.5 Gram(s)
Maximum serving Sizes:
1.5 Gram(s)
Servings per container
66
UPC/BARCODE
633422822723
IngredientAmount% DV
Calories5 Calorie(s)--
Total Carbohydrates1 Gram(s)1%
Reishi1.5 Gram(s)--

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Brand IP Statement(s)

Host Defense Mushrooms Powered by Mushroom Mycelium

Formula

Reishi supports whole-body wellness, vitality, and a calm, relaxed body and mind.

Mushroom mycelium powder

Formulation

Sustainably grown in the USA under the supervision of Paul Stamets, our mushroom mycelium is cultured on organic brown rice. This bioavailable powder has a mild flavor and can be mixed in your favorite recipe.

Vegan

GF Gluten free

Longevity support

Non GMO

Certified Organic by the WSDA

Precautions

Caution: If you have a medical condition, are taking medications, or are pregnant or breastfeeding, consult a healthcare professional before using this product.

Keep out of reach of children.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

General Statements

Paul Stamets Fungi Perfecti, LLC Eco packaging

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

USDA Organic

Certified Organic Washington State Department of Agriculture organic program

Suggested/Recommended/Usage/Directions

Directions: Adults take 1/2 tsp. 1-3 times per day.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Reishi by Host Defense Mushrooms label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Reishi label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Reishi by Host Defense Mushrooms

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1.5 Gram(s) Dosage formPowder Servings per container66 Amounts shown are per serving.

Reishi

Interacts with
375 drugs
1.5 Gram(s) per serving Form: Ganoderma lucidum

Reishi is a traditional Asian mushroom widely used to support the immune system and overall wellness. Human evidence for most of its claimed benefits...

Reishi monograph & interactions
Interaction report

Reishi by Host Defense Mushrooms Drug Interactions

Want to check YOUR meds against Reishi?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
375Drugs
375 Moderate

Ingredients driving the most interactions

Reishi 375

Individual Drug Interactions

The ingredients in Reishi interact with 375 drugs. Click any drug to see the details.

1 of the 1 ingredient in Reishi interact with drugs. Each result below shows which ingredient is responsible. Reishi

Each ingredient & the kinds of drugs it affects

For each ingredient in Reishi with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Reishi3 drug types · 375 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, high doses of reishi mushroom might increase the risk of bleeding.
A dose of 1.5 grams daily of reishi mushroom does not seem to decrease platelet aggregation, but a higher dose of 3 grams daily does.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, reishi mushroom might have additive effects with antidiabetes drugs.
Animal research suggests that reishi mushroom decreases blood sugar. However, in patients with type 2 diabetes, taking reishi mushroom does not reduce fasting glucose levels, and its effects on glycated hemoglobin are inconsistent.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, concurrent use of reishi mushroom with antihypertensive drugs might increase the risk of hypotension.
Reishi mushroom has shown hypotensive activity in animal research. Clinical evidence suggests that reishi mushroom reduces blood pressure in some, but not all, patients with hypertension.

Likelihood Possible Evidence D
Reishi full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Reishi, from the product label.

Host Defense Mushrooms

See all Host Defense Mushrooms products
Name
Fungi Perfecti, LLC
Street Address
PO Box 7634
City
Olympia
State
WA
ZipCode
98507
Phone Number
877-504-6926
Web Address
Hostdefense.com
Pharmacist Counseling Corner

Reishi by Host Defense Mushrooms: Common Questions

Does Reishi by Host Defense Mushrooms interact with any medications?
Yes. Based on its ingredients, Reishi has a known interaction with 375 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Reishi contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take Reishi if I'm on a blood thinner like warfarin?
Not without checking first. Reishi can affect how your blood clots, especially at doses of 3 grams daily or higher. Your pharmacist or doctor needs to review your specific dose and medication to see if it's safe together.
Will Reishi lower my blood pressure too much if I'm already on blood pressure medicine?
That's the concern. Reishi has shown some blood-pressure-lowering activity in both animal studies and some people. Taking it alongside blood pressure medication could theoretically push your pressure down further. Have your pharmacist check before you start.
Does Reishi actually work for cholesterol?
According to the data we hold, reishi appears to be possibly ineffective for lowering cholesterol. If that's why you're considering it, there may be better options to discuss with your doctor.
Is it safe to take Reishi long-term?
Short-term use is generally well tolerated, but long-term safety hasn't been well studied. If you're thinking about taking it regularly over months or years, talk with your pharmacist about what we do and don't know.
Can I take Reishi while pregnant or breastfeeding?
There isn't enough safety data, so it's best avoided during pregnancy and while breastfeeding. Talk with your doctor if you have questions about your individual situation.
What side effects should I watch for?
The most common are dizziness, dry mouth, itching, nausea, rash, and stomach upset. Some people report respiratory allergy to reishi spores, sore throat, or runny nose. Insomnia and headache are rare but have been reported.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Reishi is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Reishi label
Go deeper

The Full Monographs Behind Reishi’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Reishi Mushroom

Interacts with 375 drugs

Reishi is a traditional Asian mushroom widely used to support the immune system and overall wellness. Human evidence for most of its claimed benefits is limited or low-quality, so it should...

Read the full Reishi Mushroom monograph →
Sources

Sources & How We Checked

Reishi's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 17 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Reishi Mushroom 17 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Tao J, Feng KY. Experimental and clinical studies on inhibitory effect of ganoderma lucidum on platelet aggregation. J Tongji Med Univ 1990;10:240-3. PubMed
  3. Singh AB, Gupta SK, Pereira BM, Prakash D. Sensitization to Ganoderma lucidum in patients with respiratory allergy in India. Clin Exp Allergy 1995;25:440-7.
  4. Lee SY, Rhee HM. Cardiovascular effects of mycelium extract of Ganoderma lucidum: inhibition of sympathetic outflow as a mechanism of its hypotensive action. Chem Pharm Bull (Tokyo) 1990;38:1359-64. PubMed
  5. Kwok Y, Ng KFJ, Li, CCF, et al. A prospective, randomized, double-blind, placebo-controlled study of the platelet and global hemostatic effects of Ganoderma lucidum (Ling-Zhi) in healthy volunteers. Anesth Analg 2005;101:423-6. PubMed
  6. Wanmuang, H., Leopairut, J., Kositchaiwat, C., Wananukul, W., and Bunyaratvej, S. Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder. J Med Assoc Thai. 2007;90(1):179-181.
  7. Seto, S. W., Lam, T. Y., Tam, H. L., Au, A. L., Chan, S. W., Wu, J. H., Yu, P. H., Leung, G. P., Ngai, S. M., Yeung, J. H., Leung, P. S., Lee, S. M., and Kwan, Y. W. Novel hypoglycemic effects of Ganoderma lucidum water-extract in obese/diabetic (+db/+db
  8. Chu, T. T., Benzie, I. F., Lam, C. W., Fok, B. S., Lee, K. K., and Tomlinson, B. Study of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial. Br.J.Nutr. 2012;107(7):1017-1027.
  9. Jin, X., Ruiz, Beguerie J., Sze, D. M., and Chan, G. C. Ganoderma lucidum (Reishi mushroom) for cancer treatment. Cochrane.Database.Syst.Rev. 2012;6:CD007731.
  10. Kabir, Y., Kimura, S., and Tamura, T. Dietary effect of Ganoderma lucidum mushroom on blood pressure and lipid levels in spontaneously hypertensive rats (SHR). J Nutr Sci Vitaminol.(Tokyo) 1988;34(4):433-438. PubMed
  11. Kanmatsuse, K., Kajiwara, N., Hayashi, K., Shimogaichi, S., Fukinbara, I., Ishikawa, H., and Tamura, T. [Studies on Ganoderma lucidum. I. Efficacy against hypertension and side effects]. Yakugaku Zasshi 1985;105(10):942-947. PubMed
  12. Gao, Y., Lan, J., Dai, X., Ye, J., and Zhou, S. A Phase I/II Study of Ling Zhi Mushroom Ganoderma lucidum(W.Curt: Fr.) Lloyd (Aphyllophoromycetideae) Extract in Patients with Type II Diabetes Mellitus. International Journal of Medicinal Mushrooms 2004;6. DOI
  13. Jin H, Zhang G, Cao X, and et al. Treatment of hypertension by linzhi combined with hypotensor and its effects on arterial, arteriolar and capillary pressure and microcirculation. In: Niimi H, Xiu RJ, Sawada T, and et al. Microcirculatory Approach to Asi
  14. Klupp NL, Chang D, Hawke F, Kiat H, Cao H, Grant SJ, Bensoussan A. Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev. 2015 Feb 17;2:CD007259. PubMed
  15. Zhao H, Zhang Q, Zhao L, Huang X, Wang J, Kang X. Spore Powder of Ganoderma lucidum Improves Cancer-Related Fatigue in Breast Cancer Patients Undergoing Endocrine Therapy: A Pilot Clinical Trial. Evid Based Complement Alternat Med. 2012;2012:809614.
  16. Pazzi F, Adsuar JC, Domínguez-Muñoz FJ, García-Gordillo MA, Gusi N, Collado-Mateo D. Ganoderma lucidum effects on mood and health-related quality of life in women with fibromyalgia. Healthcare (Basel) 2020;8(4):520. PubMed
  17. Kogure T, Koiwai A, Fukushi D, et al. Hypereosinophilia with hepatic nodule formation caused by Ganoderma lucidum. Intern Med 2021;60(24):3897-3903.

See these in context on the Reishi Mushroom monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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