Interactions on record — worth a quick check against your medications. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Four Kings Ingredients & Drug Interactions

by Ron Teeguarden's Dragon Herbs

Capsule Category: Botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Four Kings is a dietary supplement by Ron Teeguarden's Dragon Herbs with 4 active ingredients. Its ingredients are commonly taken for fatigue and low energy, athletic performance and stamina, respiratory and lung support.Based on those ingredients, 502 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Maitake Fruiting Body Extract, Powder, Cordyceps Mycelium Extract, Powder, Agaricus Fruiting Body Extract, Powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Four Kings by Ron Teeguarden's Dragon Herbs

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

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 4 active ingredients.
  • “Proprietary Extract Formula” is a proprietary blend — the label gives one combined amount (1,500 mg) without saying how much of each component you get.

Four Kings contains four active ingredients: cordyceps mycelium extract, agaricus fruiting body extract, maitake mushroom fruiting body extract, and reishi fruiting body extract, plus inactive ingredients (pullulan polysaccharide, rice powder, bamboo extract, and rice extract blend) that serve as fillers and capsule material.

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.

Why this rating?
  • The label markets this product for: four mushrooms for tonic and protective benefits.
  • We looked for evidence on: Fatigue, Hypercholesterolemia, Hyperlipidemia, Hypertension, Diabetes, Athletic performance — and 4 related terms.
  • The closest evidence on file: Cordyceps is rated "Possibly Ineffective" for Athletic performance (Natural Medicines).
  • Also on file: Maitake Mushroom is rated "Insufficient Reliable Evidence To Rate" for Chronic fatigue syndrome (CFS), Diabetes, Chemotherapy-related fatigue, Hyperlipidemia, and more.
  • Also on file: Cordyceps is rated "Insufficient Reliable Evidence To Rate" for Fatigue.

The evidence for Four Kings' ingredients is limited. Cordyceps is rated possibly ineffective for athletic performance, but the data is insufficient to rate it for sexual function, heart rhythm, asthma, lung cancer, or COPD.

For maitake, the evidence is likewise insufficient to rate its use for hay fever, chemotherapy-related anemia, laryngeal cancer, chemotherapy-related diarrhea, or chronic fatigue. We hold no effectiveness ratings for agaricus or reishi from the data on file.

The evidence, ingredient by ingredient Cordyceps Agaricus Mushroom Maitake 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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Cordyceps is generally well tolerated short-term, though long-term safety data is limited and product quality varies widely. The most common side effects are abdominal discomfort, constipation, and diarrhea — symptoms that may be reduced by taking it with food.

One case report links cordyceps to liver inflammation, though it is unclear whether cordyceps or a contaminant caused it. Maitake is generally well tolerated as a food, though concentrated supplement safety has not been fully studied.

Gastrointestinal effects (diarrhea, stomach pain) are the most common, and rarely a rash or itching has been reported. Cordyceps and maitake should both be avoided during pregnancy and breastfeeding due to insufficient safety data.

We hold no safety information for agaricus or reishi on file.

Side effects, ingredient by ingredient Cordyceps Agaricus Mushroom Maitake 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?
  • 3 of the 3 matched ingredients can interact with medications — Maitake Mushroom, Cordyceps, Agaricus Mushroom.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 502 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 with your pharmacist if you take warfarin or other blood thinners — maitake has a documented case of increased bleeding risk with warfarin. Also double-check if you're on blood pressure drugs, diabetes medications, antiplatelet drugs like aspirin, or immunosuppressants — cordyceps and maitake both carry Moderate interactions with these drug types.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Four Kings is a blend of medicinal mushroom extracts. If you take warfarin, blood thinners, blood pressure meds, diabetes drugs, or immunosuppressants, check your exact medications with the tool on this page before starting — the cordyceps and maitake here have documented interactions with these drug classes.

Talk to your pharmacist before use, especially if you're pregnant, breastfeeding, or taking any prescription medications.

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

Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 22, 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 Four Kings, straight from the product label.

Brand Ron Teeguarden's Dragon Herbs
Barcode (UPC) 679372001979
Net contents 100 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 22, 2024
DSLD ID 316881
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Four Kings by Ron Teeguarden's Dragon Herbs, 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:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
33
UPC/BARCODE
679372001979
IngredientAmount% DV
Proprietary Extract Formula1500 mg--
Cordyceps Mycelium Extract, Powder0 NP--
Agaricus Fruiting Body Extract, Powder0 NP--
Maitake Fruiting Body Extract, Powder0 NP--
Duanwood Reishi Fruiting Body Extract, Powder0 NP--

Other ingredients: Pullulan Polysaccharide, Rice, Powder, Bamboo Extract, Powder, Rice extract Blend

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.
Formula

Four Kings consists of four mushrooms that are known for their powerful tonic and protective benefits.

Pullulan caps - 100% natural, water-soluble polysaccharide produced through a fermentation process; vegetable origin; non-GMO; no starch, preservatives or chemical modifications; gluten free.

Formulation

This formulation is both safe and effective.

Pullulan caps - 100% natural, water-soluble polysaccharide produced through a fermentation process; vegetable origin; non-GMO; no starch, preservatives or chemical modifications; gluten free.

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.

Brand IP Statement(s)

Ron Teeguarden's Dragon Herbs Health Deserves Cultivation

FDA Statement of Identity

Dietary Supplement

General Statements

Four Kings 500 mg each

Suggested/Recommended/Usage/Directions

Directions: Take 3 capsules, 2 times per day or as directed by a healthcare professional.

Precautions

Keep out of the reach of children.

See for yourself

Four Kings by Ron Teeguarden's Dragon Herbs label

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

What’s inside

The Ingredients in Four Kings by Ron Teeguarden's Dragon Herbs

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container33 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Extract Formula

1500 mg per serving

Other (inactive) ingredients: Pullulan Polysaccharide, Rice, Powder, Bamboo Extract, Powder, Rice extract Blend. These complete the product’s ingredient list but are not active constituents.

Interaction report

Four Kings by Ron Teeguarden's Dragon Herbs Drug Interactions

Want to check YOUR meds against Four Kings?

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
502Drugs
494 Moderate 8 Minor

Each ingredient & the kinds of drugs it affects

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

Maitake Fruiting Body Extract, Powder3 drug types · 260 drugs

Antidiabetes Drugs

Theoretically, combining maitake mushroom with antidiabetes drugs might increase the risk of hypoglycemia.
Clinical research shows that taking maitake mushroom polysaccharide (MMP) can lower blood glucose levels in patients with types 2 diabetes.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, combining maitake mushroom with antihypertensive drugs might increase the risk of hypotension.
Animal research shows that maitake mushroom can lower blood pressure.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is limited evidence that maitake mushroom may increase the anticoagulant effects of warfarin.
In a case report, a patient previously stabilized on warfarin developed an elevated international normalized ratio (INR) of 5.1 after taking maitake mushroom (Grifron-Pro Maitake D-Fraction) 1 drop/kg daily in three divided doses for one week. The elevated INR resolved after holding warfarin for two days, then reducing the dose by 11%. It is thought that the beta-glucan constituent of maitake mushroom might cause warfarin dissociation from proteins, resulting in increased free warfarin levels and increased warfarin effects.

Likelihood Possible Evidence D

Cordyceps Mycelium Extract, Powder3 drug types · 249 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, cordyceps may increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
In vitro and animal research suggests that cordyceps extract inhibits platelet aggregation and function. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, concurrent use of cordyceps might interfere with immunosuppressive therapy.
Animal and in vitro research suggests that cordyceps stimulates the immune system. However, limited clinical research suggests that taking cordyceps may lower the necessary therapeutic dose of the immunosuppressant cyclosporine, which suggests that cordyceps may have an immunosuppressive effect.

Likelihood Possible Evidence B
Testosterone

Theoretically, concurrent use of cordyceps and testosterone might have additive effects.
Animal research suggests that cordyceps can increase testosterone levels. The clinical significance of this finding is unclear.

Likelihood Possible Evidence D

Agaricus Fruiting Body Extract, Powder1 drug type · 86 drugs

Antidiabetes Drugs

Theoretically, taking agaricus mushroom with antidiabetes drugs might increase the risk of hypoglycemia.
In one clinical study in patients with type 2 diabetes who are stabilized on conventional oral hypoglycemic agents, 3 of 29 patients taking an agaricus mushroom extract 500 mg three times daily for 12 weeks reported hypoglycemia, compared to one of 29 patients in the placebo group.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Four Kings, from the product label.

Ron Teeguarden's Dragon Herbs

See all Ron Teeguarden's Dragon Herbs products
Name
Ron Teeguarden's Dragon Herbs
City
Los Angeles
State
CA
ZipCode
90036
Phone Number
(888) 558-6642
Web Address
www.dragonherbs.com
Pharmacist Counseling Corner

Four Kings by Ron Teeguarden's Dragon Herbs: Common Questions

Does Four Kings by Ron Teeguarden's Dragon Herbs interact with any medications?
Yes. Based on its ingredients, Four Kings has a known interaction with 502 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Four Kings contains 4 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
Does cordyceps in Four Kings actually improve athletic performance?
Cordyceps is rated possibly ineffective for athletic performance based on the evidence we have. The data doesn't support a benefit for that use.
Can I take Four Kings if I'm pregnant or breastfeeding?
No — the safety data for both cordyceps and maitake is too limited, and the facts advise against concentrated mushroom supplements during pregnancy and while breastfeeding. Talk with your doctor or pharmacist about whether it's right for you.
What side effects might I experience from Four Kings?
The most common side effects are digestive: abdominal discomfort, diarrhea, and constipation. Taking it with food may help. Dry mouth and throat discomfort have also been reported. Rarely, a rash or itching has occurred. If you experience stomach pain or diarrhea that doesn't improve, stop and talk to your pharmacist.
How long can I safely take Four Kings?
Cordyceps is generally well tolerated for up to 1 year. Maitake as a food is considered safe long-term, but supplement safety data is limited. If you're taking it longer than a few months, check with your pharmacist.
Is there a case of someone being harmed by cordyceps in Four Kings?
There is one case report of a person taking a cordyceps-containing product who developed liver inflammation with jaundice, but recovered when they stopped. It's unclear whether cordyceps or an unknown contaminant caused it, so the link is not established.
What are maitake and reishi in this product supposed to do?
The evidence is insufficient to rate maitake for conditions like hay fever, cancer-related side effects, or chronic fatigue. We hold no effectiveness information for reishi on file, so we can't say what role it's meant to play in this blend.

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

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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.

Four Kings label
Sources

Sources & How We Checked

Four Kings'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 27 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.

Cordyceps 14 references
  1. Zhu JS, Halpern GM, Jones K. The scientific rediscovery of an ancient Chinese herbal medicine: Cordyceps sinensis: part I. J Altern Complement Med 1998;4:289-303.
  2. Zhu JS, Halpern GM, Jones K. The scientific rediscovery of a precious ancient Chinese herbal regimen: Cordyceps sinensis: part II. J Altern Complement Med 1998;4:429-57.
  3. Chen YJ, Shiao MS, Lee SS, Wang SY. Effect of Cordyceps sinensis on the proliferation and differentiation of human leukemic U937 cells. Life Sci 1997;60:2349-59. PubMed
  4. Zhao Y. [Inhibitory effects of alcoholic extract of Cordyceps sinensis on abdominal aortic thrombus formation in rabbits]. Chung Hua I Hsueh Tsa Chih (Taipei) 1991;71:612-5, 42.
  5. Chen GZ, Chen GL, Sun T, et al. Effects of Cordyceps sinensis on murine T lymphocyte subsets. Chin Med J (English) 1991;104:4-8.
  6. Zhu XY, Yu HY. [Immunosuppressive effect of cultured Cordyceps sinensis on cellular immune response]. Chung Hsi I Chieh Ho Tsa Chih 1990;10:485-7, 454.
  7. Hsu, C. C., Huang, Y. L., Tsai, S. J., Sheu, C. C., and Huang, B. M. In vivo and in vitro stimulatory effects of Cordyceps sinensis on testosterone production in mouse Leydig cells. Life Sci 9-5-2003;73(16):2127-2136. PubMed
  8. Ikumoto, T., Sasaki, S., Namba, H., Toyama, R., Moritoki, H., and Mouri, T. [Physiologically active compounds in the extracts from tochukaso and cultured mycelia of Cordyceps and Isaria]. Yakugaku Zasshi 1991;111(9):504-509. PubMed
  9. Wu, T. N., Yang, K. C., Wang, C. M., Lai, J. S., Ko, K. N., Chang, P. Y., and Liou, S. H. Lead poisoning caused by contaminated Cordyceps, a Chinese herbal medicine: two case reports. Sci.Total Environ. 4-5-1996;182(1-3):193-195. PubMed
  10. Hong T, Zhang M, Fan J. Cordyceps sinensis (a traditional Chinese medicine) for kidney transplant recipients (Review). Cochrane Database Syst Rev. 2015;(10):CD009698. doi: 10.1002/14651858.CD009698.pub2.
  11. Zhang HW, Lin ZX, Tung YS, Kwan TH, Mok CK, Leung C, Chan LS. Cordyceps sinensis (a traditional Chinese medicine) for treating chronic kidney disease (Review). Cochrane Database Syst Rev. 2014;(12):CD008353. doi: 10.1002/14651858.CD008353.pub2. PubMed
  12. Bee Yean O, Zoriah A. Efficacy of Cordyceps sinensis as an adjunctive treatment in hemodialysis patients: a systematic review and Meta-analysis. J Tradit Chin Med. 2019;39(1):1-14.
  13. Thurian D, Montani M, Stickel F. Drug-induced, mixed-type hepatitis following ingestion of Cordyceps sinensis. Int J Clin Pharmacol Ther 2022;60(2):115-120. PubMed
  14. Yu X, Mao Y, Shergis JL, et al. Effectiveness and safety of oral Cordyceps sinensis on stable COPD of GOLD stages 2-3: Systematic review and meta-analysis. Evid Based Complement Alternat Med. 2019;2019:4903671.

See these in context on the Cordyceps monograph →

Agaricus Mushroom 5 references
  1. Hsu CH, Liao YL, Lin SC, et al. The mushroom Agaricus Blazei Murill in combination with metformin and gliclazide improves insulin resistance in type 2 diabetes: a randomized, double-blinded, and placebo-controlled clinical trial. J Altern Complement Med 2
  2. Mukai H, Watanabe T, Ando M, Katsumata N. An alternative medicine, Agaricus blazei, may have induced severe hepatic dysfunction in cancer patients. Jpn J Clin Oncol 2006;36:808-10. PubMed
  3. Ohno S, Sumiyoshi Y, Hashine K, et al. Phase I clinical study of the dietary supplement, Agaricus blazei Murill, in cancer patients in remission. Evid Based Complement Alternat Med 2011, doi 10.1155/2011/192381.
  4. Suehiro M, Katoh N, Kishimoto S. Chelitis due to Agaricus blazei Murill mushroom extract. Contact Dermatitis 2007;56(5):293-4.
  5. Iwai N, Okuda T, Sawada R, et al. Interstitial lung disease associated with Agaricus blazei Murill in a patient with pancreatic ductal adenocarcinoma receiving gemcitabine-based therapy. Case Rep Gastroenterol 2022;16(1):229-234.

See these in context on the Agaricus Mushroom monograph →

Maitake Mushroom 8 references
  1. Kabir Y, Kimura S. Dietary mushrooms reduce blood pressure in spontaneously hypertensive rats (SHR). J Nutr Sci Vitaminol (Tokyo) 1989;35:91-4. PubMed
  2. Kabir Y, Yamaguchi M, Kimura S. Effect of shiitake (Lentinus edodes) and maitake (Grifola frondosa) mushrooms on blood pressure and plasma lipids of spontaneously hypertensive rats. J Nutr Sci Vitaminol (Tokyo) 1987;33:341-6. PubMed
  3. Konno S, Tortorelis DG, Fullerton SA, et al. A possible hypoglycaemic effect of maitake mushroom on Type 2 diabetic patients. Diabet Med 2001;18:1010. PubMed
  4. Chen JT, Tominaga K, Sato Y, et al. Maitake mushroom (Grifola frondosa) extract induces ovulation in patients with polycystic ovary syndrome: a possible monotherapy and a combination therapy after failure with first-line clomiphene citrate. J Altern Compl
  5. Hanselin MR, Vande Griend JP, Linnebur SA. INR elevation with maitake extract in combination with warfarin. Ann Pharmacother 2010;44:223-4. PubMed
  6. Talpur, N. A., Echard, B. W., Fan, A. Y., Jaffari, O., Bagchi, D., and Preuss, H. G. Antihypertensive and metabolic effects of whole Maitake mushroom powder and its fractions in two rat strains. Mol.Cell Biochem. 2002;237(1-2):129-136. PubMed
  7. Deng, G., Lin, H., Seidman, A., Fornier, M., D'Andrea, G., Wesa, K., Yeung, S., Cunningham-Rundles, S., Vickers, A. J., and Cassileth, B. A phase I/II trial of a polysaccharide extract from Grifola frondosa (Maitake mushroom) in breast cancer patients: i
  8. Wesa KM, Cunningham-Rundles S, Klimek VM, et al. Maitake mushroom extract in myelodysplastic syndromes (MDS): a phase II study. Cancer Immunol Immunother 2015;64(2):237-47. PubMed

See these in context on the Maitake 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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