Drug & supplement interaction

Oregano + Mepolizumab

Mepolizumab brand name: Nucala.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Oregano and Mepolizumab in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Oregano and Mepolizumab

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Mepolizumab and Oregano in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Oregano safety at a glance

Oregano overall Use caution Safe as a food, but concentrated oregano oil supplements are stronger and less studied.
Pregnancy Possibly Unsafe When used orally in medicinal amounts. Oregano is thought to have abortifacient and emmenagogue effects. Read the full pregnancy detail
Breastfeeding Use caution Stick to normal food amounts; safety of supplements while breastfeeding is not established.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Pharmacist analysis

Oregano (and oregano oil) supplements are generally considered safe and there is no indication that there is an interaction between the drug highlighted in this interaction monograph and oregano.

However, as with all supplements, it is important to talk to your doctor before starting anything new, so you can be appropriately monitored.

In terms of drug interactions that have been reported with oregano, below are some examples.

Anticoagulant; Antiplatelet Drugs

Anticoagulants and antiplatelet drugs work by slowing down or preventing blood clotting. While they are essential medications for individuals with certain conditions, they come with an increased risk of bleeding.

Some studies have reported that oregano oil may also increase the risk of bleeding, as it contains compounds that have antithrombin activity and can inhibit platelet aggregation.

Therefore, taking oregano oil along with anticoagulants or antiplatelet drugs may increase the risk of bleeding, bruising, and other adverse effects.

Anti-Diabetic Drugs

Several studies suggest that oregano supplements may help lower blood glucose (i.e., sugar) levels. In vitro and animal research has shown that oregano extracts might stimulate glucose uptake and reduce blood glucose levels.

Therefore, based on the available evidence, combining oregano oil with antidiabetic drugs could potentially cause blood sugar levels to drop too low, leading to hypoglycemia.

However, it is important to note that studies reporting that oregano can reduce blood glucose levels have not reported it causing hypoglycemia.

References

  • Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region. PubMed
  • Inhibitory effect of clonal oregano extracts against porcine pancreatic amylase in vitro. PubMed
  • Antithrombin activity of some constituents from Origanum vulgare. PubMed
  • Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. PubMed

Still wondering about combining Mepolizumab and Oregano? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Keep it in perspective

Oregano Does Interact With Other Medications

Oregano has 208 moderate known drug interactions in our database — Mepolizumab isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Oregano

Covers the 2,830 medications we’ve checked against Oregano. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Oregano and Mepolizumab May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • An allergic reaction Worth acting on Additional detail

    Oregano

    “Systemic allergic reactions have been reported with oregano. A 45-year-old male developed pruritus, respiratory difficulty, hypotension, swelling of the lips and tongue, and facial edema after ingesting pizza seasoned with oregano. He had 2 similar episodes after ingesting foods seasoned with thyme, another member of the Lamiaceae family.”

    Oregano · Natural Medicines adverse-effect record, reported in hypotension.

    1 source cited
    1. 3705. 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

    Mepolizumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Mepolizumab. Read the label on DailyMed ›

  • Itching Additional detail

    Oregano

    Recorded for Oregano in the same Natural Medicines adverse-effect record shown under An allergic reaction above.

    Mepolizumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Mepolizumab. Read the label on DailyMed ›

Reported for Oregano but not commonly for Mepolizumab: stomach upset, low blood pressure, a severe allergic reaction and a skin rash.

Effects for Mepolizumab come from the ADVERSE REACTIONS section of its FDA label; effects for Oregano come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 49,399 voluntary FDA FAERS reports for Mepolizumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Oregano in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally in medicinal amounts. Oregano is thought to have abortifacient and emmenagogue effects.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Overlapping uses

What Mepolizumab Is Prescribed For, and What Oregano Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Mepolizumab is a prescription medicine with approved uses on its FDA label. Oregano is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Mepolizumab is prescribed for: Nucala is used as an add-on maintenance treatment — meaning it works alongside other medications, not instead of them. It is approved for severe asthma (in patients 6 years and older with high eosinophil levels), chronic rhinosinusitis with nasal polyps (CRSwNP) in adults 18 and older whose symptoms aren't controlled by nasal corticosteroids alone, and COPD in adults with an eosinophilic phenotype whose disease isn't adequately controlled. Nucala is also approved to treat eosinophilic granulomatosis with polyangiitis (EGPA), a rare form of blood vessel inflammation, and hypereosinophilic syndrome (HES), a condition involving dangerously elevated eosinophil counts, in adults and adolescents 12 and older. It is not meant to relieve sudden asthma attacks or acute COPD flares.

Oregano has been studied for:

  • Rhinosinusitis studied, not established Oregano has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Oregano for rhinosinusitis

    Although there has been interest in using oral oregano for rhinosinusitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.

  • Asthma studied, not established Oregano has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Oregano for asthma

    Although there has been interest in using oral oregano for asthma, there is insufficient reliable information about the clinical effects of oregano for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Mepolizumab on your own; if you are taking Oregano for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Oregano or Mepolizumab

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Oregano or Mepolizumab, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

One more smart check

Taking Oregano as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,632 real supplement products containing Oregano, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Oregano. Even though Oregano itself has no known interaction with Mepolizumab, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Oregano and Mepolizumab Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Oregano
Top 10%

#140 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Mepolizumab
Steady interest

#1,766 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Oregano reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Oregano and Mepolizumab records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Oregano

What is Oregano?

Oregano
  • Digestive upset
  • Respiratory and cold symptoms
  • Antimicrobial support
  • Intestinal parasites
  • Skin and fungal concerns

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 have antimicrobial and antioxidant properties, strong human evidence for treating any specific health condition is limited. Used as a food, oregano is very safe; concentrated oregano oil supplements should be used cautiously and discussed with your pharmacist or doctor.

Origanum vulgare · Lamiaceae · Leaves and essential oil · Culinary herb, tea, capsules, softgels, liquid oil (oil of oregano), tinctures

An interaction check asks whether these two react with each other — it does not ask whether Oregano is a good idea for someone in your situation. Here is what our Oregano record says about it on its own.

Oregano: dosing

There is no official, well-established dose for oregano supplements. Products vary widely in strength and in how much carvacrol they contain, so it is hard to compare them.The safest approach is to follow the directions on the product label and not exceed the recommended amount.

From our Oregano monograph — the full record covers uses, side effects and every documented interaction.

Read the full Oregano monograph & all interactions
Medication

About Mepolizumab Injection

What Is Mepolizumab Injection Used For?

Brand name: Nucala

Nucala is used as an add-on maintenance treatment — meaning it works alongside other medications, not instead of them. It is approved for severe asthma (in patients 6 years and older with high eosinophil levels), chronic rhinosinusitis with nasal polyps (CRSwNP) in adults 18 and older whose symptoms aren't controlled by nasal corticosteroids alone, and COPD in adults with an eosinophilic phenotype whose disease isn't adequately controlled.

Nucala is also approved to treat eosinophilic granulomatosis with polyangiitis (EGPA), a rare form of blood vessel inflammation, and hypereosinophilic syndrome (HES), a condition involving dangerously elevated eosinophil counts, in adults and adolescents 12 and older. It is not meant to relieve sudden asthma attacks or acute COPD flares.

Most-Reported Side Effects for Mepolizumab

From FAERS, the FDA’s public side-effect reporting system (49,399 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Asthma 12,767 reports
Dyspnea 10,576 reports
Wheezing 7,131 reports
Cough 5,100 reports
Therapeutic product effect incomplete 5,051 reports
See full Mepolizumab Injection drug information
Keep checking

Other Drugs & Oregano

Browse every other medication we’ve checked against Oregano — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
208Moderate
0Minor
2,621No known interaction
Moderate

208 interactions

Showing 60 of 208 moderate interactions — see all 208 on the Oregano page.

No interaction 2,621 drugs checked — show the list
Evidence & sources

Oregano References

The 12 references that drive our Oregano monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Oregano and Mepolizumab Together: Common Questions

Is it safe to take Oregano with Mepolizumab?
We do not list a known interaction between Oregano and Mepolizumab. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Oregano and Mepolizumab have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Oregano and Mepolizumab used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Oregano in each. That is a conversation for your prescriber, especially if Mepolizumab is being adjusted to a target.
Does Oregano interact with any other medications?
Yes. Oregano has 208 documented drug interactions in our database — Mepolizumab is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

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

Still Have a Question About Mepolizumab and Oregano?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.