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

Fungus Fighter Ingredients & Drug Interactions

by Herb Pharm Professional

Fungus Fighter label
See full label image
Liquid 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 Fungus Fighter 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

Fungus Fighter is a dietary supplement by Herb Pharm Professional with 4 active ingredients. Its ingredients are commonly taken for sore throat, skin and wound care, respiratory infections.Based on those ingredients, 208 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Oregano extract, Pau d'Arco extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Fungus Fighter by Herb Pharm Professional

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HelloPharmacist Scorecard of Fungus Fighter by Herb Pharm Professional

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

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 Blend” is a proprietary blend — the label gives one combined amount (630 mg) without saying how much of each component you get.

Fungus Fighter contains 4 active ingredients in a proprietary extract blend: usnea extract, oregano extract, spilanthes extract, and pau d'arco extract, delivered in a liquid form. The product also contains certified organic cane alcohol, distilled water, and certified organic vegetable glycerin as inactive ingredients.

Each of these extracts has a traditional history in herbal use, though the evidence supporting their effectiveness for specific conditions remains limited, as detailed below.

Does it work?

Insufficient evidence
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
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Fungal infection support and immune health.
  • We looked for evidence on: Tinea capitis, Tinea corporis, Tinea pedis, Dandruff, Seborrheic dermatitis, Urinary tract infections (UTIs) — and 4 related terms.
  • The closest evidence on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Upper respiratory tract infection (URTI) (Natural Medicines).
  • Also on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Seborrheic dermatitis, Urinary tract infections (UTIs), Wound healing, Tinea corporis, and more.

The evidence for what Fungus Fighter's ingredients actually do is not well established. Usnea has insufficient reliable evidence for cough, pain, wound healing, tinea pedis (athlete's foot), and obesity.

Oregano extract similarly lacks solid evidence for acne, bronchitis, asthma, headache, and upper respiratory infections. Pau d'arco shows insufficient reliable evidence for cancer, peptic ulcers, wound healing, and dysmenorrhea (menstrual cramps).

We have no effectiveness data on file for spilanthes extract.

The evidence, ingredient by ingredient Usnea Oregano Pau D'arco

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.

Usnea carries the most serious safety concern: when taken by mouth, its constituent usnic acid has been linked to liver damage (hepatotoxicity). Topical use is generally better tolerated, though it can cause contact dermatitis, conjunctivitis, and local irritation in sensitive people.

The product advises avoiding usnea during pregnancy and breastfeeding due to insufficient safety data. Oregano extract is well tolerated in food amounts but less studied at higher supplement doses.

Gastrointestinal upset is the most common side effect; dermatitis can occur topically in sensitive people. Rare systemic allergic reactions, including anaphylaxis, have been reported.

Avoid medicinal amounts during pregnancy; stick to food amounts while breastfeeding. Pau d'arco may cause side effects at higher doses, with nausea, vomiting, diarrhea, and anemia reported when the lapachol constituent exceeds 1.5 grams daily.

Avoid during pregnancy and breastfeeding due to insufficient safety data.

Side effects, ingredient by ingredient Usnea Oregano Pau D'arco

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?
  • 2 of the 3 matched ingredients can interact with medications — Oregano, Pau D'arco.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 208 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 before using this product if you take blood thinners or antiplatelet drugs (warfarin, clopidogrel, aspirin, etc.) — oregano and pau d'arco may increase bleeding risk. Also double-check if you take diabetes medications, as oregano may lower blood sugar.

If you're on any prescription medication at all, run it through the checker below.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with insufficient evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product is not right for anyone taking blood thinners, diabetes medications, or who is pregnant or breastfeeding. If you're considering it for a specific condition, know that the evidence supporting its ingredients is limited.

Talk to your pharmacist before starting, especially if you take any regular medications or have liver concerns — usnea's potential for liver damage in oral form is a real consideration.

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 Feb 25, 2019.

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 Fungus Fighter, straight from the product label.

Brand Herb Pharm Professional
Barcode (UPC) 090700026554
Net contents 2 fl. Oz.; 60 mL
Market status On market
Date entered into DSLD Feb 25, 2019
DSLD ID 199918
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Fungus Fighter by Herb Pharm Professional, 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:
0.7 mL
Maximum serving Sizes:
0.7 mL
Servings per container
84
UPC/BARCODE
090700026554
IngredientAmount% DV
Proprietary Extract Blend630 mg--
Usnea extract0 NP--
Oregano extract0 NP--
Spilanthes extract0 NP--
Pau d'Arco extract0 NP--

Other ingredients: certified organic Cane Alcohol, distilled Water, certified organic Vegetable Glycerin

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.
Suggested/Recommended/Usage/Directions

Suggested use Shake well before using Add 1 full squeeze of the dropper bulb to 2 oz. of water or juice, 2 to 4 times per day. Best taken between meals. Practitioner may increase dosage if desired.

Precautions

Keep out of the reach of children

Storage

Store away from heat & light

General

003

Formula

Spilanthes - Usnea

FDA Statement of Identity

Herbal Supplement

Formulation

Gluten-free

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

See for yourself

Fungus Fighter by Herb Pharm Professional label

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

Fungus Fighter 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 Fungus Fighter by Herb Pharm Professional

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

Serving size0.7 mL Dosage formLiquid Servings per container84 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 Blend

630 mg per serving

Other (inactive) ingredients: Certified organic Cane Alcohol, Distilled Water, Certified organic Vegetable Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Fungus Fighter by Herb Pharm Professional Drug Interactions

Want to check YOUR meds against Fungus Fighter?

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
208Drugs
208 Moderate

Ingredients driving the most interactions

Oregano extract 208
Pau d'Arco extract 122

Individual Drug Interactions

The ingredients in Fungus Fighter interact with 208 drugs. Click any drug to see the details.

2 of the 4 ingredients in Fungus Fighter interact with drugs. Each result below shows which ingredient is responsible. Oregano extract Pau d'Arco extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Fungus Fighter 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.

Oregano extract2 drug types · 208 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, oregano might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that aristolochic acid isolated from oregano leaves has antithrombin activity. It has also been reported that oregano oil inhibits arachidonic acid-induced, and ADP-induced, platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, oregano might increase the risk for hypoglycemia when taken with antidiabetes drugs.
In vitro and animal research shows that oregano extracts might lower blood glucose levels.

Likelihood Possible Evidence D
Oregano extract full monograph & interactions

Pau d'Arco extract1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, pau d'arco might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that pau d'arco reduces platelet aggregation and may interfere with vitamin K. One clinical study shows that taking the lapachol constituent of pau d'arco in doses above 1.5 grams daily increases the risk of bleeding. The effects of whole pau d'arco or pau d'arco extract in humans are unclear.

Likelihood Possible Evidence D
Pau d'Arco extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Fungus Fighter, from the product label.

Herb Pharm Professional

See all Herb Pharm Professional products
Name
Herb Pharm
City
Williams
State
OR
ZipCode
97544
Phone Number
800-348-4372
Web Address
www.herb-pharm.com
Pharmacist Counseling Corner

Fungus Fighter by Herb Pharm Professional: Common Questions

Does Fungus Fighter by Herb Pharm Professional interact with any medications?
Yes. Based on its ingredients, Fungus Fighter has a known interaction with 208 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Fungus Fighter 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.
Is Fungus Fighter safe to take with blood thinners like warfarin?
No — this product is not a good match. Both oregano and pau d'arco in it may increase your bleeding risk when combined with blood thinners. Talk to your doctor or pharmacist before considering it.
Can I use this product if I'm pregnant?
No. The product contains usnea, oregano, and pau d'arco — all of which advise against use in pregnancy due to insufficient safety data or possible harm to the developing baby.
What's the main safety concern with usnea in this product?
When taken by mouth, usnea contains usnic acid, which has been linked to liver damage. Topical use is generally better tolerated, but this is a liquid you swallow, so that's a real consideration if you have liver concerns or take it long-term.
Will this lower my blood sugar if I'm on diabetes medication?
Possibly. Oregano extract in this product may theoretically lower blood glucose levels. If you take diabetes drugs, talk to your pharmacist before adding this product — you may need your blood sugar monitored more closely.
What does each ingredient in this product do?
The product contains usnea, oregano, pau d'arco, and spilanthes extracts, but we don't have solid evidence that any of them work for specific conditions. The research is too limited to say whether this product will help with what you're hoping to treat.
Does oregano extract in here have common side effects?
When used in food amounts, oregano is well tolerated. At supplement doses, gastrointestinal upset is the most common side effect. Rare systemic allergic reactions, including anaphylaxis, have been reported in sensitive people.

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.

Fungus Fighter label
Go deeper

The Full Monographs Behind Fungus Fighter’s Ingredients

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

Herb & supplement monograph

Usnea

Usnea is a lichen used in traditional herbal medicine, mainly for sore throats, skin infections, and as a general antimicrobial. Laboratory studies suggest its main compound, usnic acid, can...

Read the full Usnea monograph → Herb & supplement monograph

Oregano

Interacts with 208 drugs

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacrol. While lab studies suggest it may hav...

Read the full Oregano monograph → Herb & supplement monograph

Pau D'arco

Interacts with 122 drugs

Pau d'arco is a South American tree bark traditionally used for infections and inflammation, and it contains compounds like lapachol that show activity in lab studies. However, strong human...

Read the full Pau D'arco monograph →
Sources

Sources & How We Checked

Fungus Fighter'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 28 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.

Usnea 10 references
  1. Favreau JT, Ryu Ml, Braunstein G, et al. Severe hepatotoxicity associated with the dietary supplement LipoKinetix. Ann Intern Med 2002;136:590-5. PubMed
  2. Ingolfsdottir K. Usnic acid. Phytochemistry 2002;61:729-36.
  3. Scirpa, P., Scambia, G., Masciullo, V., Battaglia, F., Foti, E., Lopez, R., Villa, P., Malecore, M., and Mancuso, S. [A zinc sulfate and usnic acid preparation used as post-surgical adjuvant therapy in genital lesions by Human Papillomavirus]. Minerva Gin
  4. Mitchell, J. C. Allergy to lichens. Allergic contact dermatitis from usnic acid produced by lichenized fungi. Arch Dermatol 1965;92(2):142-146.
  5. Durazo, F. A., Lassman, C., Han, S. H., Saab, S., Lee, N. P., Kawano, M., Saggi, B., Gordon, S., Farmer, D. G., Yersiz, H., Goldstein, R. L., Ghobrial, M., and Busuttil, R. W. Fulminant liver failure due to usnic acid for weight loss. Am.J Gastroenterol. PubMed
  6. Neff, G. W., Reddy, K. R., Durazo, F. A., Meyer, D., Marrero, R., and Kaplowitz, N. Severe hepatotoxicity associated with the use of weight loss diet supplements containing ma huang or usnic acid. J Hepatol. 2004;41(6):1062-1064. PubMed
  7. Hsu, L. M., Huang, Y. S., Chang, F. Y., and Lee, S. D. 'Fat burner' herb, usnic Acid, induced acute hepatitis in a family. J Gastroenterol.Hepatol. 2005;20(7):1138-1139. PubMed
  8. Arneborn, P., Jansson, A., and Bottiger, Y. [Acute hepatitis in a woman after intake of slimming pills bought via Internet]. Lakartidningen 7-11-2005;102(28-29):2071-2072.
  9. Sanchez, W., Maple, J. T., Burgart, L. J., and Kamath, P. S. Severe hepatotoxicity associated with use of a dietary supplement containing usnic acid. Mayo Clin Proc 2006;81(4):541-544. PubMed
  10. Rafanelli, S., Bacchilega, R., Stanganelli, I., and Rafanelli, A. Contact dermatitis from usnic acid in vaginal ovules. Contact Dermatitis 1995;33(4):271-272. PubMed

See these in context on the Usnea monograph →

Oregano 12 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Benito M, Jorro G, Morales C, et al. Labiatae allergy: systemic reactions due to ingestion of oregano and thyme. Ann Allergy Asthma Immunol 1996;76:416-8. PubMed
  3. Chevallier A. Encyclopedia of Herbal Medicine. 2nd ed. New York, NY: DK Publ, Inc., 2000.
  4. Ciganda C, and Laborde A. Herbal infusions used for induced abortion. J Toxicol.Clin Toxicol. 2003;41:235-239. PubMed
  5. Futrell, J. M. and Rietschel, R. L. Spice allergy evaluated by results of patch tests. Cutis 1993;52(5):288-290.
  6. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  7. Goun, E., Cunningham, G., Solodnikov, S., Krasnykch, O., and Miles, H. Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia 2002;73(7-8):692-694. PubMed
  8. Lemhadri, A., Zeggwagh, N. A., Maghrani, M., Jouad, H., and Eddouks, M. Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region. J Ethnopharmacol. 2004;92(2-3):251-256. PubMed
  9. McCue, P., Vattem, D., and Shetty, K. Inhibitory effect of clonal oregano extracts against porcine pancreatic amylase in vitro. Asia Pac.J Clin.Nutr. 2004;13(4):401-408.
  10. Ragi, J., Pappert, A., Rao, B., Havkin-Frenkel, D., and Milgraum, S. Oregano extract ointment for wound healing: a randomized, double-blind, petrolatum-controlled study evaluating efficacy. J.Drugs Dermatol. 2011;10(10):1168-1172.
  11. Singletary K. Oregano: overview of the literature on health benefits. Nutrition Today 2010;45(3):129-38.
  12. Silva MLAE, Lucarini R, Dos Santos FF, et al. Hypoglycemic effect of rosmarinic acid-rich infusion (RosCE) from Origanum vulgare in alloxan-induced diabetic rats. Nat Prod Res 2022;36(17):4525-4531.

See these in context on the Oregano monograph →

Pau D'arco 6 references
  1. Gómez Castellanos JR, Prieto JM, Heinrich M. Red Lapacho (Tabebuia impetiginosa)--a global ethnopharmacological commodity? J Ethnopharmacol 2009;121:1-13. PubMed
  2. Guerra, Mde O., Mazoni, A. S., Brandao, M. A., and Peters, V. M. Toxicology of Lapachol in rats: embryolethality. Braz.J Biol. 2001;61(1):171-174. PubMed
  3. Felicio, A. C., Chang, C. V., Brandao, M. A., Peters, V. M., and Guerra, Mde O. Fetal growth in rats treated with lapachol. Contraception 2002;66(4):289-293. PubMed
  4. Son, D. J., Lim, Y., Park, Y. H., Chang, S. K., Yun, Y. P., Hong, J. T., Takeoka, G. R., Lee, K. G., Lee, S. E., Kim, M. R., Kim, J. H., and Park, B. S. Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular s
  5. Block JB, Serpick AA, Miller W, Wiernik PH. Early clinical studies with lapachol (NSC-11905). Cancer Chemother Rep 2. 1974;4(4):27-8.
  6. Algranti E, Mendonça EM, Ali SA, Kokron CM, Raile V. Occupational asthma caused by Ipe (Tabebuia spp) dust. J Investig Allergol Clin Immunol 2005;15(1):81-3.

See these in context on the Pau D'arco 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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