Oregano Oil

Potent antimicrobial essential oil with powerful respiratory support properties, containing high levels of carvacrol and thymol

Scientific nameOriganum vulgare FormulaC10H14O (carvacrol) Molecular weight150.22 g/mol CAS499-75-2

85 absorption score

6 safety / 10

35 USD per month

5 documented interactions

Check it against something

Evidence level C

Oregano Oil with:

80 out of 100

Works better together Compatible. Timing differs, so follow each supplement's own window.

Check it against your whole stack →

What it does

mechanism and evidence for each claim

Powerful antimicrobial respiratory protection

Potent broad-spectrum antimicrobial support against respiratory infections

Carvacrol and thymol provide powerful antimicrobial effects against bacteria, viruses, and fungi Evidence A-grade 1-5 days

Respiratory infection treatment

Natural support for treating respiratory tract infections

High concentration of antimicrobial compounds fights respiratory pathogens Evidence B-grade 2-7 days

Immune system respiratory support

Enhances immune function specifically for respiratory tract protection

Immune-modulating compounds strengthen respiratory immunity Evidence B-grade 1-4 weeks

Anti-inflammatory respiratory relief

Reduces inflammation in respiratory tract and airways

Anti-inflammatory compounds reduce respiratory tissue inflammation Evidence C-grade 1-3 weeks

Antioxidant lung protection

Provides antioxidant protection for lung tissues and respiratory health

Phenolic compounds provide antioxidant protection against oxidative damage Evidence C-grade 2-8 weeks

Others take these for the same thing

Same goal, different mechanism — check any of them against this one

Creatine Monohydrate Strength & power enhancement 3-5g A 95% Probiotics for Autoimmune Disease Support Gut health & immune modulation 10-100 billion CFU daily B 60% Calcium Bone health & muscle function 1,000-1,200 mg A 30% Magnesium Glycinate Superior absorption sleep & muscle support 200-600 mg A 90% Vitamin D3 Bone health & immune support 1000-2000 IU A 85% Whey Protein Muscle growth & recovery 25-75g A 95%

Every pair we checked

12 combinations scored by the engine

Oregano Oil + Lactobacillus acidophilus May reduce beneficial bacteria along with harmful ones Needs attention 52

Oregano Oil + Iron Sulfate May reduce iron absorption Needs attention 58

Oregano Oil + Caffeine No documented interaction either way No known interaction 70

Oregano Oil + Creatine Monohydrate No documented interaction either way No known interaction 70

Oregano Oil + Calcium Carbonate No documented interaction either way No known interaction 70

Oregano Oil + Whey Protein No documented interaction either way No known interaction 70

Oregano Oil + Lactase No documented interaction either way No known interaction 70

Oregano Oil + Bovine Collagen No documented interaction either way No known interaction 70

Oregano Oil + DHA No documented interaction either way No known interaction 70

Oregano Oil + Vitamin D3 Enhanced immune and antioxidant support Works better together 75

Oregano Oil + Thyme Enhanced antimicrobial and respiratory support Works better together 80

Oregano Oil + Eucalyptus Synergistic antimicrobial and decongestant support Works better together 80

Dosage

With meals

Daily100-300mg

Acute infections150-300mg daily (short-term)

Immune support100-200mg daily

Chronic conditions100-200mg daily (with breaks)

Prevention100-150mg daily as needed

Before you take it

VeganYes

When to expect it

First Effects1-5 days for antimicrobial effects against respiratory infections

Peak Benefits1-4 weeks for immune support and respiratory protection

Deficiency DevelopmentNot applicable - herbal supplement

Toxicity OnsetPossible with high doses or prolonged use

How to measure it

$60-100

MarkerLiver enzymes if long-term use, bleeding time if on blood thinners

OptimalNormal liver function, normal bleeding parameters

Deficient belowNot applicable for herbal supplement

FrequencyMonitor if using long-term or with blood thinners

What people actually reported to the FDA

CAERS, 10 reports naming it as the suspect

Most reported effects

Fatigue 2

Vomiting 2

Pruritus 2

Psoriasis 2

Asthenia 1

Named as the suspect 10 reports of 18 that mention it at all

Serious outcome 67% hospitalisation, emergency room or worse

Other Serious or Important Medical Event6

Other Outcome3

Visited Emergency Room2

Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →

What actually reaches you

The label counts the carrier, your body does not

Absorption Very high 85 of 100 · best absorbed form of this compound

Delivered daily 170 mg

Cost per 100 mg delivered $0.69 comparative — uses the absorption score, not a measured percentage

Works better with

3 documented

Thyme

Enhanced antimicrobial and respiratory support

Both contain thymol and provide complementary antimicrobial effects · level C

Eucalyptus

Synergistic antimicrobial and decongestant support

Both provide powerful antimicrobial effects for respiratory infections · level C

Vitamin C

Enhanced immune and antioxidant support

Complementary immune-enhancing and antioxidant effects · level C

What not to take with Oregano Oil

2 documented

Probiotics

May reduce beneficial bacteria along with harmful ones

Broad-spectrum antimicrobial effects can affect gut flora · moderate significance

Iron Supplements

May reduce iron absorption

Tannins and compounds may bind iron · mild significance

Medication interactions

Discuss these with a pharmacist before combining

blood-thinners Moderate

May enhance anticoagulant effects

What to do: Monitor bleeding parameters closely

diabetes-medications Minor

May affect blood sugar levels

What to do: Monitor blood glucose levels

immunosuppressive-medications Minor

May interfere with immunosuppressive therapy

What to do: Monitor immune function

Available forms

bioavailability compared

Oregano Oil (Standardized 70%+ Carvacrol) 85

Oregano Oil (Standardized 70%+ Carvacrol): Extremely potent antimicrobial, Fast acting, Broad spectrum, Strong research

Food sources

before you supplement

Wild oregano essential oil Highest concentration of carvacrol · 85

Fresh wild oregano leaves Lower concentration than oil · 45

Dried oregano herb Moderate concentration · 40

Cooking oregano (marjoram) Much lower carvacrol content · 20

Too little

deficiency signs

Not applicable (herbal supplement, not essential nutrient):
General symptoms addressed by oregano oil:
Frequent respiratory infections and poor immunity
Chronic or recurrent respiratory tract infections
Poor resistance to respiratory pathogens
Slow recovery from respiratory illnesses
Compromised respiratory tract immunity

Too much

toxicity signs

Potential concerns with high doses or prolonged use:
Severe digestive upset and stomach irritation
Mouth and throat burning or irritation
Increased bleeding risk
Skin irritation and allergic reactions
Liver stress with very high doses

Who benefits most

respiratory-infections-acute

Powerful natural antimicrobial for acute respiratory tract infections

150-300mg daily during infection (short-term)

immune-support-respiratory

Potent immune enhancer specifically for respiratory tract protection

100-200mg daily

chronic-respiratory-conditions

Antimicrobial and anti-inflammatory support for chronic respiratory issues

100-200mg daily (with breaks)

travel-infection-prevention

Preventive antimicrobial support during travel or exposure risk

100-150mg daily as prevention

seasonal-respiratory-support

Seasonal immune and respiratory support during cold and flu season

100-200mg daily during season

Where to buy it

compare forms first

Look for Oregano Oil at 100-300mg per serving. The form that matters here is Oregano Oil (Standardized 70%+ Carvacrol).

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How it works

Carvacrol and thymol provide powerful broad-spectrum antimicrobial effects
Disrupts bacterial cell membranes leading to pathogen destruction
Anti-inflammatory compounds reduce respiratory tract inflammation
Immune-modulating effects enhance respiratory tract immunity
Antioxidant phenolic compounds protect respiratory tissues
Antiviral properties help fight respiratory viral infections

Key findings

what the evidence supports

Extremely potent antimicrobial effects comparable to antibiotics
Effective against antibiotic-resistant bacteria in studies
Strong evidence for respiratory infection treatment
Requires careful dosing due to potency and potential side effects

Sources: NIH Examine.com · data reviewed 2026-08-02

Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →

Common questions

What are the benefits of Oregano Oil?

Documented effects: Powerful antimicrobial respiratory protection; Respiratory infection treatment; Immune system respiratory support; Anti-inflammatory respiratory relief. Potent broad-spectrum antimicrobial support against respiratory infections

How much Oregano Oil should you take per day?

The common daily range is 100-300mg. By goal — acute infections: 150-300mg daily (short-term); immune support: 100-200mg daily; chronic conditions: 100-200mg daily (with breaks); prevention: 100-150mg daily as needed.

When is the best time to take Oregano Oil?

With meals. First effects are typically reported within 1-5 days for antimicrobial effects against respiratory infections.

What are the side effects of Oregano Oil?

At excessive doses: Potential concerns with high doses or prolonged use:, Severe digestive upset and stomach irritation, Mouth and throat burning or irritation, Increased bleeding risk, Skin irritation and allergic reactions. Safety rating at normal doses is 6 out of 10.

What should you not take with Oregano Oil?

Separate it from Probiotics, Iron Supplements by two to four hours. May reduce beneficial bacteria along with harmful ones

Does Oregano Oil interact with medications?

Documented interactions with blood-thinners, diabetes-medications, immunosuppressive-medications. Discuss these with a pharmacist before combining.

How do you know if you need Oregano Oil?

The marker is Liver enzymes if long-term use, bleeding time if on blood thinners, optimal range Normal liver function, normal bleeding parameters. Common deficiency signs: Not applicable (herbal supplement, not essential nutrient):, General symptoms addressed by oregano oil:, Frequent respiratory infections and poor immunity, Chronic or recurrent respiratory tract infections.

Taken for

59 Immunity

Vitamin D3 · Vitamin C (Ascorbic Acid) · Comprehensive Immune Support Complex

43 Performance

Caffeine · Creatine Monohydrate · Whey Protein