# Oregano Leaves (Origanum vulgare)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/oregano-leaves
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-29
**Evidence Score:** 2 / 10
**Category:** Fruit
**Also Known As:** Origanum vulgare, Common oregano, Wild marjoram, Pizza herb, Mountain mint, Winter marjoram, Pot marjoram, Turkish oregano, Mediterranean oregano, European oregano

## Overview

Oregano leaves (Origanum vulgare) contain carvacrol and rosmarinic acid as primary bioactive compounds that exhibit antioxidant and [antimicrobial](/ingredients/condition/immune-support) properties. These compounds work by scavenging [free radical](/ingredients/condition/antioxidant)s and disrupting bacterial cell membranes.

## Health Benefits

• [Antioxidant activity](/ingredients/condition/antioxidant) demonstrated in vitro with CUPRAC values of 1284 µM TE/g and FRAP values of 794 µM TE/g (preliminary evidence only) • Lipid oxidation inhibition shown in laboratory studies, with extracts extending lag phase to 812 minutes at 2.5 µg (no human trials) • Potential [antimicrobial](/ingredients/condition/immune-support) effects from essential oil compounds like carvacrol (up to 74.3%) and thymol (up to 58.57%) (preclinical data only) • [Anti-inflammatory](/ingredients/condition/inflammation) properties suggested by triterpene acids including rosmarinic acid (12 mg/g in extracts) (mechanistic studies only) • Rich polyphenolic content (94.69 mg GAE/g) indicating possible systemic antioxidant effects (no clinical validation)

## Mechanism of Action

Carvacrol disrupts bacterial cell membrane integrity by altering membrane fluidity and permeability. Rosmarinic acid and other phenolic compounds neutralize [reactive oxygen species](/ingredients/condition/antioxidant) through electron donation mechanisms. The antioxidant activity involves metal chelation and inhibition of lipid peroxidation cascades.

## Clinical Summary

Current evidence is limited to in vitro studies demonstrating [antioxidant](/ingredients/condition/antioxidant) capacity with CUPRAC values of 1284 µM TE/g and FRAP values of 794 µM TE/g. Laboratory studies show lipid oxidation inhibition extending lag phase to 812 minutes at 2.5 µg extract concentration. No human clinical trials have been conducted to validate therapeutic effects. Evidence remains preliminary and requires human studies for clinical validation.

## Nutritional Profile

{"macronutrients": {"protein": "11.0 g per 100 g", "fiber": "42.5 g per 100 g", "fat": "4.3 g per 100 g", "carbohydrates": "68.9 g per 100 g"}, "micronutrients": {"vitamins": {"vitamin K": "621.7 \u00b5g per 100 g", "vitamin E": "18.26 mg per 100 g", "vitamin C": "2.3 mg per 100 g"}, "minerals": {"calcium": "1576 mg per 100 g", "iron": "44 mg per 100 g", "magnesium": "270 mg per 100 g", "potassium": "1260 mg per 100 g", "zinc": "4.4 mg per 100 g"}}, "bioactive_compounds": {"carvacrol": "up to 74.3% in essential oil", "thymol": "up to 58.57% in essential oil", "rosmarinic acid": "up to 20 mg per g"}, "bioavailability_notes": "The bioavailability of oregano's compounds can vary. Fat-soluble vitamins like vitamin E and K may be better absorbed with dietary fats. The bioavailability of minerals such as iron can be influenced by the presence of other dietary components like vitamin C, which can enhance absorption."}

## Dosage & Preparation

No clinically studied dosage ranges are available as human trials are absent. Preclinical studies used extracts at 0.25–2.5 µg/mL for in vitro assays, with standardization targeting carvacrol (up to 74.3%), thymol (0.2–21.3%), or rosmarinic acid (0.12–6.8%). Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Oregano leaves are generally safe when consumed as food seasoning but may cause allergic reactions in sensitive individuals. High doses may interact with anticoagulant medications due to potential blood-thinning effects. Concentrated extracts should be avoided during pregnancy and breastfeeding due to insufficient safety data. May enhance effects of diabetes medications requiring blood sugar monitoring.

## Scientific Research

The research dossier explicitly states that search results lack human clinical trials, RCTs, or meta-analyses for oregano leaves (O. vulgare). Available evidence is limited to in vitro [antioxidant](/ingredients/condition/antioxidant) assays and preclinical [antimicrobial](/ingredients/condition/immune-support) studies, with no PubMed PMIDs for human studies provided.

## Historical & Cultural Context

The research dossier does not specify historical or traditional medicine contexts for O. vulgare leaves. Modern analyses highlight its value as a nutrient-dense food source of polyphenols, but no traditional systems or historical uses are described in the available data.

## Synergistic Combinations

Rosemary, Thyme, Green Tea Extract, Vitamin C, Turmeric

## Frequently Asked Questions

### What are the main active compounds in oregano leaves?

The primary bioactive compounds are carvacrol (phenolic monoterpene), rosmarinic acid (phenolic acid), and thymol. Carvacrol typically represents 60-80% of the essential oil content and provides most antimicrobial activity.

### How much carvacrol is in oregano leaves?

Oregano leaves contain 0.1-1% essential oil, with carvacrol comprising 60-80% of that oil content. This translates to approximately 600-800 mg carvacrol per 100g of dried oregano leaves.

### Can oregano leaves help with bacterial infections?

Laboratory studies show oregano extracts inhibit various bacteria including E. coli and Staphylococcus aureus through membrane disruption. However, no human clinical trials have tested oregano leaves for treating bacterial infections.

### What is the recommended dosage for oregano leaf supplements?

No standardized dosage exists due to lack of clinical trials. Traditional use suggests 1-4g dried leaves daily as tea. Concentrated extracts should follow manufacturer guidelines and medical supervision.

### Do oregano leaves interact with blood pressure medications?

Oregano may have mild hypotensive effects and could theoretically enhance blood pressure medications. Monitor blood pressure closely and consult healthcare providers before combining with antihypertensive drugs.

### Is oregano leaf supplement safe to take during pregnancy and breastfeeding?

While oregano is commonly used as a culinary herb, concentrated supplements contain higher levels of volatile compounds like carvacrol and thymol that have not been adequately studied in pregnant or breastfeeding women. Pregnant and nursing individuals should consult with their healthcare provider before taking oregano leaf supplements, as some traditional uses suggest potential uterine stimulant properties. Culinary amounts of oregano in food are generally considered safe.

### What is the difference between oregano essential oil and oregano leaf extract supplements?

Oregano essential oil is a concentrated distillate containing high levels of volatile compounds (carvacrol up to 74.3%, thymol up to 58.57%) and is typically taken in small doses (often in capsules), while oregano leaf extracts are made by soaking dried leaves in solvents and may contain different compound profiles depending on extraction methods. Essential oil is more potent but carries higher risk of gastrointestinal irritation at higher doses, whereas leaf extracts may have gentler effects. The bioavailability and efficacy can differ significantly between these two forms.

### Does oregano leaf supplementation have strong clinical evidence in humans?

Most evidence for oregano's health benefits comes from in vitro laboratory studies and animal models rather than human clinical trials; antioxidant activity has been demonstrated in preliminary lab work (CUPRAC values of 1284 µM TE/g), but human efficacy studies are limited. While traditional use and preclinical research suggest potential benefits for antimicrobial and antioxidant effects, the quality of evidence for human health outcomes remains preliminary. More robust clinical trials in human populations are needed to establish effectiveness and optimal dosing.

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