Oregano

Scientific Name(s): Origanum onites L., Origanum syriacum L., Origanum vulgare L.
Common Name(s): Kekik, Mediterranean oregano, Mexican oregano, Mountain mint, Wild marjoram, Winter marjoram, Wintersweet

Medically reviewed by Drugs.com. Last updated on Oct 4, 2021.

Clinical Overview

Use

Aside from its culinary application, oregano exhibits antimicrobial and antioxidant actions and has possible activity as an antispasmodic and in diabetes. However, there is limited clinical trial evidence to support the use of oregano for any indication.

Dosing

There is no clinical evidence to support specific therapeutic doses of oregano; however, due to its wide use in foods, it has been designated GRAS (generally recognized as safe) status by the FDA. In a small study, 200 mg/day emulsified O. vulgare oil was administered for 6 weeks.

Contraindications

Contraindications have not been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking. GRAS status when used as food. Ingestion in excess of amounts found in food should be avoided because safety and efficacy are unproven. Some studies indicate hormonal effects.

Interactions

None well documented.

Adverse Reactions

Oregano has caused allergic contact dermatitis when applied topically. When oregano is ingested, eczematous rash and, rarely, anaphylactic reactions can occur.

Toxicology

Information in humans is lacking.

Scientific Family

• Lamiaceae (mint)

Botany

Common or wild oregano is a perennial plant native to the Mediterranean region and Asia and cultivated in the United States. Its creeping rootstock produces a square, downy, purplish stem with opposite ovate leaves. Stems can grow up to 76 cm tall and are dotted with small depressions. Purple, 2-lipped flowers grow in terminal clusters from July to October.1, 2, 3

O. vulgare subspecies hirtum has a spicy flavor, furry leaves on stems that grow up to 45.7 cm tall, and floppy white flowers.1 Several Turkish species of Origanum are also found in commerce, including O. onites L. and O. syriacum L.4 Other taxa in the genera Coridothymus, Thymbra, and Satureja have similar chemistry.4Lippia graveolens Kunth. (Verbenaceae) is known as Mexican oregano.

Molecular techniques to distinguish these related species for purposes of quality control have been developed.5, 6, 7, 8

History

Oregano has been a common ingredient in Spanish, Mexican, and Italian dishes as a spice and flavoring agent for hundreds of years. Its initial purpose was as a warming digestive and circulatory stimulant. It has been used in perfumery for its volatile oil contents, especially in scenting soaps.

The antiseptic qualities of aromatic and medicinal plants and their extracts, including oregano, have been recognized since ancient times.9 Attempts to characterize these properties in the laboratory date back to the early 1900s.

Antispasmodic, calmative, carminative, diaphoretic, expectorant, stomachic, and tonic actions have been reported. It has been suggested that an infusion of the fresh herb is beneficial in treating an upset stomach and indigestion, headache, colic, and nervous complaints, as well as for coughs and other respiratory ailments. An infusion of the flowers has been used to prevent seasickness. The oil has been used exter...