Lamiaceae
Origanum vulgare
Oregano · Wild marjoram
- Part used
- leafaerialoil
- Native range
- Europe, the Mediterranean and western Asia
- Morphology
- An aromatic perennial to about eighty centimetres with small oval leaves and loose heads of small pink-purple flowers among purple bracts. Chemically extremely variable between populations.
What is in it
Evidence
Very little controlled human evidence. Carvacrol has genuine and well-characterised antimicrobial activity in the laboratory, which has not been demonstrated to translate into treating infection in people.
Safety
Culinary use is benign. Oregano oil is a strong mucous membrane irritant and must never be taken neat. Marketed heavily as a natural antibiotic, which is a claim with no clinical support and a real risk if it delays treatment of a genuine infection.
Interactions: Theoretical additive with anticoagulants; May affect blood glucose
Regulatory: Permitted as a food. Oil products are widely sold with unsupported antimicrobial claims.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
Used across the Mediterranean for digestive and respiratory complaints. The name is from Greek roots usually glossed as joy of the mountain.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
Worth knowing
Oregano oil is the best current example of a laboratory finding being sold as a clinical one.
Carvacrol kills bacteria in a dish. That is real, reproducible and not in dispute. It says nothing about whether swallowing oregano oil reaches an infection anywhere in the body at a concentration that matters — and the pharmacokinetics suggest strongly that it does not.
The gap matters because of what the marketing invites. A "natural antibiotic" taken for something that needs an actual antibiotic is the delay mechanism described under medical harm, and it is the commonest way an otherwise harmless plant hurts someone.
The species is also chemically wild. Different populations of Origanum vulgare produce oils dominated by carvacrol, by thymol, or by neither, so two bottles with the same label can be quite different products.
Nomenclature verified against GBIF backbone taxonomy.