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Dietary supplement

Oregano Leaf Ingredients & Drug Interactions

by Herb Stop

Oregano Leaf label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Oregano Leaf 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

Oregano Leaf is a dietary supplement by Herb Stop with 1 active ingredient. Its ingredients are commonly taken for digestive upset, respiratory and cold symptoms, antimicrobial support.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. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Oregano Leaf by Herb Stop

Ask about any prescription or over-the-counter medication and we check it for interactions with Oregano Leaf by Herb Stop — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Oregano Leaf by Herb Stop

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 Aug 27, 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.

This product contains one active ingredient: oregano leaf. Oregano is an herb traditionally used in cooking and herbal medicine.

The capsule itself is made from plant cellulose (hydroxypropyl methylcellulose) and purified water—just the standard inactive ingredients that hold the herb together.

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 Oregano's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: supports healthy immune response.
  • We looked for evidence on: Upper respiratory tract infection (URTI), Bronchitis, Cough, Rhinosinusitis, Intestinal parasite infection, Immune function — and 2 related terms.
  • The closest evidence on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Bronchitis (Natural Medicines).
  • Also on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Upper respiratory tract infection (URTI), Cough, Intestinal parasite infection, Rhinosinusitis.

The evidence we hold for oregano doesn't establish that it works for any of the conditions listed: acne, bronchitis, asthma, headache, and upper respiratory tract infection all show insufficient reliable evidence to rate. That doesn't mean oregano doesn't help—it means the research isn't solid enough yet to know.

If you're considering it for one of these reasons, talk with your doctor or pharmacist about what the current evidence actually supports for your situation.

The evidence, ingredient by ingredient 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 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.

When you eat oregano as a food seasoning, it's well tolerated and safe. As a concentrated supplement in a capsule, there's much less safety data available.

The most common side effect from taking oregano by mouth is mild stomach upset. Rarely, some people have had serious allergic reactions, including anaphylaxis (a severe whole-body reaction), or contact dermatitis (skin irritation) if applied topically.

During pregnancy, the safety data advises against medicinal or supplement amounts of oregano—food amounts are likely fine. While breastfeeding, there isn't enough data to know whether supplement amounts are safe, so talk with your doctor or pharmacist for personalized advice.

If you have a known allergy to oregano or related herbs in the mint family (like thyme), you should avoid this product.

Side effects, ingredient by ingredient 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?
  • 1 of the 1 matched ingredient can interact with medications — Oregano.
  • 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.

Before you start Herb Stop Oregano Leaf, check with your doctor or pharmacist if you take blood thinners or antiplatelet drugs (like warfarin, apixaban, clopidogrel, or aspirin)—oregano may increase bleeding risk. Also double-check if you're on diabetes medications, since oregano might lower blood sugar too far.

These are Moderate severity interactions, so it's worth a conversation before you add the supplement.

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.

Oregano leaf might appeal to you if you're interested in traditional herbal support, but the evidence for its effectiveness isn't established yet. If you take blood thinners, antiplatelet drugs, or diabetes medications, you need to check your exact prescriptions before starting this—the interaction risk is real.

Talk with your doctor or pharmacist about whether this fits your health picture and whether it's safe to combine with what you're already taking.

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 Sep 25, 2023.

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 Oregano Leaf, straight from the product label.

Brand Herb Stop
Net contents 300 Veggie Capsule(s)
Market status On market
Date entered into DSLD Sep 25, 2023
DSLD ID 297389
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Organic, 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 Oregano Leaf by Herb Stop, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
150
IngredientAmount% DV
Oregano664 mg--

Other ingredients: Hydroxypropyl Methylcellulose, Water, Purified

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: Take 2 capsules 2 to 3 times per day with water, or as directed by your qualified healthcare professional.

Precautions

Safety guideline: Not to be used during pregnancy or lactation. If you have a medical condition or take pharmaceutical drugs, please consult with your doctor before use.

Keep away from children.

Use only as directed on label.

Brand IP Statement(s)

Herb Stop Health in your own hands

Formula

Herbal capsule

Formulation

Supports healthy immune response

Vegan & cruelty-free

Vegan & cruelty-free Made in USA.

FDA Statement of Identity

Dietary Supplement

FDA Disclaimer Statement

These statements have 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

Oregano Leaf by Herb Stop label

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

Oregano Leaf 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 Oregano Leaf by Herb Stop

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

Serving size2 Capsule(s) Dosage formCapsule Servings per container150 Amounts shown are per serving.

Oregano

Interacts with
208 drugs
664 mg per serving Form: Origanum vulgare

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacr...

Oregano monograph & interactions

Other (inactive) ingredients: Hydroxypropyl Methylcellulose, Water, Purified. These complete the product’s ingredient list but are not active constituents.

Interaction report

Oregano Leaf by Herb Stop Drug Interactions

Want to check YOUR meds against Oregano Leaf?

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 208

Individual Drug Interactions

The ingredients in Oregano Leaf interact with 208 drugs. Click any drug to see the details.

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Oregano Leaf 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.

Oregano2 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 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Oregano Leaf, from the product label.

Herb Stop

See all Herb Stop products
Name
The Herb Stop
Street Address
PO Box 673
City
Pine
State
AZ
ZipCode
85544
Phone Number
877.345.4372
Web Address
www.herbstop.com
Pharmacist Counseling Corner

Oregano Leaf by Herb Stop: Common Questions

Does Oregano Leaf by Herb Stop interact with any medications?
Yes. Based on its ingredients, Oregano Leaf 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?
Oregano Leaf 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 oregano while I'm pregnant?
The safety data advises against medicinal or supplement amounts during pregnancy. Food amounts—like oregano in your cooking—are likely fine. Since this is a concentrated supplement, talk with your doctor or pharmacist about whether it's right for you during pregnancy.
Is oregano safe while breastfeeding?
There isn't enough data to know whether supplement amounts are safe while breastfeeding. Stick to normal food amounts, and talk with your doctor or pharmacist about whether taking this capsule is okay for you.
What's the difference between oregano in cooking and this supplement?
When you sprinkle oregano on pizza or pasta, you're using a food amount that's very safe. This capsule is a concentrated supplement, which means much higher doses—there's less research on the safety of those larger amounts, and the interaction risks are more real.
Can oregano help with a cough or cold?
The evidence we hold doesn't establish that oregano works for upper respiratory infections, bronchitis, or asthma. That doesn't mean it won't help you, just that the research isn't solid enough yet to be sure.
What side effects should I watch for?
Most people tolerate oregano fine, but mild stomach upset is the most common side effect. Rarely, people have had allergic reactions ranging from skin irritation to serious whole-body reactions. Stop and call your doctor or pharmacist if you have trouble breathing, swelling of the lips or tongue, or any sign of an allergic reaction.
Is there any oregano in this capsule besides the active ingredient?
No—the only thing in the capsule besides oregano leaf is the plant-based capsule material itself and water. There are no fillers or other herbs mixed in.

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

Not sure if Oregano Leaf is safe with your meds?

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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.

Oregano Leaf label
Go deeper

The Full Monographs Behind Oregano Leaf’s Ingredients

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

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

Oregano Leaf'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 12 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.

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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