Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Oil of Oregano Ingredients & Drug Interactions

by GNC Herbal Plus

Oil of Oregano label
See full label image
Liquid 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 Oil of Oregano 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

Oil of Oregano is a dietary supplement by GNC Herbal Plus with 2 active ingredients. Its ingredients are commonly taken for heart health, high blood pressure, high cholesterol.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 Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Oil of Oregano by GNC Herbal Plus

Ask about any prescription or over-the-counter medication and we check it for interactions with Oil of Oregano by GNC Herbal Plus — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Oil of Oregano by GNC Herbal Plus

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

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 2 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (60 mg) without saying how much of each component you get.

This product contains 2 active ingredients: extra virgin olive oil and oregano oil, blended together in a liquid form. Oregano oil is a concentrated extract from the oregano plant, while the olive oil serves as a carrier and base.

Both are traditional culinary herbs; this formula combines them into a supplement.

Does it work?

Couldn't assess
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 assessable

The label doesn't state a purpose we can grade — see each ingredient's own graded uses on its monograph instead.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence for this product's effectiveness isn't established in the data we hold. Both oregano oil and extra virgin olive oil have been studied for conditions including respiratory infections, inflammation, blood sugar support, and bone health — but the reliability of the evidence is currently insufficient to rate them for any of these uses.

The evidence, ingredient by ingredient Olive 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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Oregano oil and olive oil are well tolerated when used in typical food amounts. At supplement strength, however, both are less studied.

Common side effects with oregano oil include gastrointestinal upset; olive oil may cause headache or stomach discomfort. Rare but serious allergic reactions to oregano — including anaphylaxis — have been reported in sensitive individuals.

Topical oregano oil at high concentrations can irritate skin and mucous membranes. During pregnancy, medicinal amounts of oregano oil are possibly unsafe, though food amounts are likely fine.

For breastfeeding, safety data on supplement amounts isn't established — stick to food amounts unless you talk it over with your doctor or pharmacist. Olive tree pollen may also trigger seasonal respiratory allergies in sensitive people.

Side effects, ingredient by ingredient Olive 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 2 matched ingredients 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.

Check before taking this product if you're on blood thinners (anticoagulants) or antiplatelet drugs like warfarin or clopidogrel — oregano oil may increase bleeding risk. Also flag diabetes medications, as oregano may lower blood sugar.

Your own pharmacist or doctor can review your specific medications against this product.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This supplement combines two culinary herbs into a concentrated liquid. If you take blood thinners, antiplatelet drugs, or diabetes medications, you'll want to check with your own doctor or pharmacist before adding it.

The same goes if you're pregnant, breastfeeding, or have a known allergy to oregano or plants in the mint family. Talk it over with your pharmacist or doctor to see if it's right for you.

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

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 23, 2017.

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 Oil of Oregano, straight from the product label.

Brand GNC Herbal Plus
Barcode (UPC) 048107105440
Net contents 1 Fluid Ounce; 30 mL
Market status On market
Date entered into DSLD Jun 23, 2017
DSLD ID 74807
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, 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 Oil of Oregano by GNC Herbal Plus, 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:
0.0335 mL
Maximum serving Sizes:
0.067 mL
Servings per container
448
UPC/BARCODE
048107105440
IngredientAmount% DV
extra virgin Olive Oil0 NP--
Proprietary Blend60 mg--
Oregano Oil0 NP--

Other ingredients: None

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.
FDA Statement of Identity

Herbal Supplement

General Statements

Supports general well-being

Standardized extract

Discontinue use two weeks prior to surgery.

K0080302

Formulation

Vegetarian

General

CODE 991471 DOG

Suggested/Recommended/Usage/Directions

Directions: Shake well. As a dietary supplement, take 1 to 2 drops under tongue or mix in juice or water.

Precautions

Warning: Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition.

Keep out of reach of children.

Sealed for your protection. Do not use if seal is broken or missing.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. 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

Oil of Oregano by GNC Herbal Plus label

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

Oil of Oregano 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 Oil of Oregano by GNC Herbal Plus

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size0.0335 mL Dosage formLiquid Servings per container448 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 Blend

60 mg per serving

Other (inactive) ingredients: None. These complete the product’s ingredient list but are not active constituents.

Interaction report

Oil of Oregano by GNC Herbal Plus Drug Interactions

Want to check YOUR meds against Oil of Oregano?

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 Oil 208

Individual Drug Interactions

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

1 of the 2 ingredients in Oil of Oregano interact with drugs. Each result below shows which ingredient is responsible. Oregano Oil

Each ingredient & the kinds of drugs it affects

For each ingredient in Oil of Oregano 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.

Oregano Oil2 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 Oil full monograph & interactions
The maker

Brand information

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

GNC Herbal Plus

See all GNC Herbal Plus products
Name
General Nutrition Corporation
City
Pittsburgh
State
PA
ZipCode
15222
Phone Number
1-888-462-2548
Web Address
www.gnc.com
Pharmacist Counseling Corner

Oil of Oregano by GNC Herbal Plus: Common Questions

Does Oil of Oregano by GNC Herbal Plus interact with any medications?
Yes. Based on its ingredients, Oil of Oregano 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?
Oil of Oregano contains 2 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?
Medicinal amounts of oregano oil are possibly unsafe during pregnancy, though food amounts are likely fine. Talk with your doctor or pharmacist about whether this supplement is right for you during pregnancy — they can help you decide based on your individual situation.
What are the most common side effects?
Gastrointestinal upset is the most common side effect from oregano oil when taken in supplement amounts. Headache or stomach discomfort can also occur from the olive oil. Serious allergic reactions are rare but have been reported in sensitive individuals.
Is this product safe to use long-term?
Both oregano and olive oil are safe as foods, but concentrated supplements are much stronger and less studied over time. There's limited safety information on oregano supplements in large amounts, so it's worth discussing long-term use with your doctor or pharmacist.
Can I use this if I have a shellfish or tree nut allergy?
The facts on file don't cover shellfish or tree nut allergies. If you have either, check the full ingredient list on the label or ask your pharmacist — they can tell you whether this product is safe for you.
Does oregano oil actually work for colds or respiratory infections?
Oregano oil has been studied for upper respiratory infections and other respiratory conditions, but the evidence isn't strong enough to say whether it works. The data we hold rates the evidence as insufficient to make a recommendation.

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

Not sure if Oil of Oregano is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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

Oil of Oregano label
Go deeper

The Full Monographs Behind Oil of Oregano’s Ingredients

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

Herb & supplement monograph

Olive

Olive comes from the same tree that gives us olives and olive oil, and its leaf and fruit contain antioxidant compounds like oleuropein and hydroxytyrosol. Olive oil as part of a Mediterrane...

Read the full Olive 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

Oil of Oregano'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 14 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.

Olive 2 references
  1. Liccardi G, D'Amato M, D'Amato G. Oleaceae pollinosis: a review. Int Arch Allergy Immunol 1996;111:210-7. PubMed
  2. Somerville V, Moore R, Braakhuis A. The effect of olive leaf extract on upper respiratory illness in high school athletes: A randomised control trial. Nutrients. 2019;11(2). pii: E358. PubMed

See these in context on the Olive 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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team