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

Fungus Fighter label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 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 with 4 active ingredients. Its ingredients are commonly taken for sore throat, skin and wound care, respiratory infections.Based on those ingredients, 437 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Calendula extract, Oregano Flowering Aerial Parts 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

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HelloPharmacist Scorecard of Fungus Fighter by Herb Pharm

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 (609 mg) without saying how much of each component you get.

Fungus Fighter has four active ingredients in liquid form. The product contains a proprietary extract blend alongside spilanthes extract, usnea extract (a lichen), and oregano flowering aerial parts extract.

Two of the four ingredients we could verify showed no effectiveness rating in our data, while the oregano and calendula portions are rated as having insufficient evidence for the uses they're marketed toward. The liquid is made with certified organic cane alcohol and distilled water.

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: Cleanse and detoxify with herbal antimicrobial support.
  • We looked for evidence on: Intestinal parasite infection, Upper respiratory tract infection (URTI), Urinary tract infections (UTIs), Vaginal candidiasis, Wound healing, fungal infections — and 3 related terms.
  • The closest evidence on file: Calendula is rated "Insufficient Reliable Evidence To Rate" for Vaginal candidiasis (Natural Medicines).
  • Also on file: Calendula is rated "Insufficient Reliable Evidence To Rate" for Wound healing.
  • Also on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Upper respiratory tract infection (URTI), Intestinal parasite infection, Urinary tract infections (UTIs), Wound healing.

The evidence on whether these ingredients work for fungal infections isn't established in the data we hold. Usnea and oregano are both listed with insufficient reliable evidence ratings for conditions like wound healing, respiratory infections, and acne — none of which directly address fungal conditions.

Calendula is similarly rated as having insufficient evidence for its listed uses. We couldn't find effectiveness data for spilanthes in our system.

If you're treating a fungal infection, talk with your pharmacist or doctor about what the evidence actually supports.

The evidence, ingredient by ingredient Usnea Calendula Oregano

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 has important safety limits. Taken by mouth, it may be unsafe — the active compound usnic acid has been linked to liver damage.

Usnea is rated unsafe in pregnancy and breastfeeding, so avoid it if you're pregnant or nursing. Topical use is generally better tolerated, though it can cause contact dermatitis or eye irritation in sensitive people.

Calendula is likely unsafe in pregnancy when taken by mouth and should be avoided then. Oregano oil supplements are stronger than food amounts and less well studied; concentrated oregano is listed as possibly unsafe in pregnancy, though normal food seasoning is fine.

Oregano may cause gastrointestinal upset, and in rare cases, systemic allergic reactions. Both usnea and calendula can trigger allergies, especially if you're sensitive to ragweed or related plants.

Side effects, ingredient by ingredient Usnea Calendula Oregano

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 — Calendula, Oregano.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 437 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.

Before you take Fungus Fighter, double-check blood thinners and antiplatelet drugs (like warfarin or aspirin) — oregano may increase bleeding risk. Also check diabetes medications, which oregano might make work too well and lower your blood sugar too much.

If you take CNS depressants (sedatives, sleep aids, anxiety drugs), note that calendula carries a Minor theoretical risk, though it's considered unlikely. Use the medication checker on this page to search your prescriptions.

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.

This product is for people interested in herbal support for fungal concerns, but the evidence that it works isn't established in our data. If you take blood thinners, diabetes medications, or CNS depressants, check your exact medications with the tool on this page before you start.

Usnea's liver safety and pregnancy restrictions are important — talk with your pharmacist or doctor first if you're pregnant, breastfeeding, or have liver concerns.

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 Nov 22, 2022.

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
Barcode (UPC) 090900000590
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Nov 22, 2022
DSLD ID 275360
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
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, 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
168
UPC/BARCODE
090900000590
IngredientAmount% DV
Proprietary Extract Blend609 mg--
Spilanthes extract0 NP--
Usnea extract0 NP--
Calendula extract0 NP--
Oregano Flowering Aerial Parts Extract0 NP--

Other ingredients: certified organic Cane Alcohol, distilled Water

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.

Precautions

Keep out of the reach of children

Storage

Store away from heat & light

Formulation

Cleanse & detoxify

Gluten-free

All of the herbs in this formula are individually extracted to ensure a broad spectrum of plant compounds.

FDA Statement of Identity

Herbal Supplement

FDA Disclaimer Statement

This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.

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 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

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 container168 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

609 mg per serving

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

Interaction report

Fungus Fighter by Herb Pharm 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
437Drugs
208 Moderate 229 Minor

Ingredients driving the most interactions

Calendula extract 248
Oregano Flowering Aerial Parts Extract 208

Individual Drug Interactions

The ingredients in Fungus Fighter interact with 437 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. Calendula extract Oregano Flowering Aerial Parts 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.

Calendula extract1 drug type · 248 drugs

Cns Depressants

Theoretically, calendula might have additive effects when used with CNS depressants, although this appears to be unlikely.
Although some animal research has suggested that a saponoside constituent in calendula may have sedative effects, calendula has been used for over 30 years without reports of sedation in humans.

Likelihood Unlikely Evidence D
Calendula extract full monograph & interactions

Oregano Flowering Aerial Parts 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 Flowering Aerial Parts Extract full monograph & interactions
The maker

Brand information

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

Herb Pharm

See all Herb Pharm 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: Common Questions

Does Fungus Fighter by Herb Pharm interact with any medications?
Yes. Based on its ingredients, Fungus Fighter has a known interaction with 437 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.
Can I take this if I'm pregnant or breastfeeding?
Not without talking to your doctor first. Usnea is rated unsafe in both pregnancy and breastfeeding. Calendula is likely unsafe to take by mouth during pregnancy. Oregano supplements are possibly unsafe in pregnancy, though food amounts are fine. There isn't enough safety data on spilanthes for either situation. Please check with your pharmacist or doctor before use.
Will this cause liver damage?
Usnea, one of the active ingredients, contains usnic acid, which has been linked to liver damage when taken by mouth. The amount in this product and the risk at that dose aren't specified in our data. If you have liver disease or concerns, talk with your pharmacist before starting.
What does each ingredient actually do?
We don't have effectiveness ratings for spilanthes. Usnea, calendula, and oregano are all listed with insufficient evidence for the conditions on file — wound healing, burns, acne, respiratory issues — so we can't say whether they work for those purposes, let alone for fungal infections specifically.
Could I have an allergic reaction to this?
Yes. Both usnea and calendula can cause allergic reactions. Calendula is particularly risky if you're sensitive to ragweed, chrysanthemums, daisies, or other plants in that family — patch testing is recommended before use. Oregano can rarely trigger systemic allergic reactions, including serious ones.
What's in the bottle besides the active ingredients?
Certified organic cane alcohol and distilled water. There are no other inactive ingredients listed.
Can I use this on my skin, or do I have to swallow it?
Our data doesn't specify how this liquid is meant to be used. Because usnea is better tolerated on skin than taken by mouth, and both usnea and calendula can cause topical reactions, ask your pharmacist how to use it safely for your situation.

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

Calendula

Interacts with 248 drugs

Calendula is a flowering plant whose petals are used mainly in skin creams, oils, and ointments to soothe minor irritation and support wound healing. Some early research is promising for ski...

Read the full Calendula 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 →
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 31 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 →

Calendula 9 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Reider N, Komericki P, Hausen BM, et al. The seamy side of natural medicines: contact sensitization to arnica (Arnica montana L.) and marigold (Calendula officinalis L.). Contact Dermatitis 2001;45:269-72..
  3. Gol'dman II. [Anaphylactic shock after gargling with an infusion of Calendula]. Klin Med (Mosk) 1974;52:142-3.
  4. Paulsen E. Contact sensitization from Compositae-containing herbal remedies and cosmetics. Contact Dermatitis 2002;47:189-98. PubMed
  5. Bojadjiev C. On the sedative and hypotensive effect of preparations from the plant Calendula officinalis. Nauch Trud Visshi Med Inst Sof 1964;43:15-20.
  6. Samochowiec L. Pharmacological study of saponosides from Aralia mandshurica Rupr. et Maxim and Calendula officinalis L. Herba Pol. 1983;29:151-155.
  7. Madisetti M, Kelechi TJ, Mueller M, Amella EJ, Prentice MA. Feasibility, acceptability, and tolerability of RGN107 in the palliative wound care management of chronic wound symptoms. J Wound Care. 2017;26(Sup1):S25-S34. PubMed
  8. Final Assessment report on Calendula officinalis L., flos. European Medicines Agency: Committee on Herbal Medicinal Products (HMPC). 2018. EMA/HMPC/603409/2017. Available at: https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-cal
  9. Puaratanaarunkon T, Washrawirul C, Chuenboonngarm N, Noppakun N, Asawanonda P, Kumtornrut C. Efficacy and safety of a facial serum containing snail secretion filtrate, Calendula officinalis, and Glycyrrhiza glaba root extract in the treatment of maskne: A

See these in context on the Calendula 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 →

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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