Botanical name Origanum vulgare L
Source Leaves and Stems
Processing Method Steam distilled
Color/Consistency A thin, pale yellow to reddish or brownish liquid.
Aromatic Summary / Note / Strength of Aroma A middle note with a strong aroma, this oil has a spicy but dry and woody aroma with earthy notes.
Blend with Herbal and woody essential oils such as Cypress, Marjoram, Rosemary, and the more camphorous floral oils such as Lavender.
Also known as Oregano and Wild Marjoram, its name is from the Greek ‘joy of the mountains’ and is a common species from the mint family. It is native to the Mediterranean basin and Asia. A perennial herb, it grows from 20–80 cm tall, with leaves of up to 4 cm, and has purple, spikey flowers. The ancient Egyptians used it in food preservation, and Hippocrates used it in his medical practice. Oregano has been a popular culinary herb in Europe since time immemorial, and became popular in North America after WWII when returning soldiers posted to Italy brought back a taste for pizza.
Since oregano was originally grown in Greece, it was first used by the Greeks. They believed that this herb was created by the Goddess Aphrodite. She wanted it to be a symbol of joy growing in her garden. The word “oregano” comes from the Greek words oros, for “mountain,” and ganos, for “joy” meaning “ joy of the mountains”
The essential oil of oregano is extracted through steam distillation of fresh oregano leaves, which bear the scientific name Oreganum vulgare. Its chief components are carvacrol, thymol, cymene, caryophyllene, pinene, bisabolene, linalool, borneol, geranyl acetate, linalyl acetate, and terpinene.
Although some people who are allergic to mint and other herbaceous perennial plants may experience some discomfort while eating or touching oregano, it is not commonly known as an allergenic substance. Also, the symptoms of an allergic reaction to oregano are very mild. Toss some oregano into your next meal and see just how beneficial it can really be.
Quality Oregano oil may be adulterated by the addition of carvacrol and p-cymene (Burfield 2003).
Hazards Drug interaction; inhibits blood clotting; embryotoxicity; skin irritation (low risk); mucous membrane irritation.
Contraindications (all routes) Pregnancy, breastfeeding.
Cautions (dermal) Hypersensitive, diseased or damaged skin, children under two years of age.
Cautions (oral) Diabetic medication, anticoagulant medication, major surgery, peptic ulcer, hemophilia, other bleeding
Maximum dermal use level 1.1%
Our safety advice
Our dermal maximum is based on 87.8% total thymol and carvacrol content and a dermal limit of 1% for carvacrol and thymol
to avoid skin irritation.
Regulatory guidelines Has GRAS status.
Adverse skin reactions Undiluted Origanum oil was severely irritating to mice, and moderately irritating to rabbits. Tested
at 2% on 25 volunteers it was neither irritating nor sensitizing. Origanum oil is non-phototoxic (Opdyke 1974 p945–946). In a
CAM (chorioallantoic membrane of the fertile chicken egg) assay, a model for detecting irritants, Origanum onites oil with
57.4% carvacrol and 11.6% thymol was strongly irritating. This irritation was due to thymol and not to carvacrol.
Cardiovascular effects Origanum vulgare oil inhibits platelet aggregation (Tognolini et al 2006), an essential step in the blood
clotting cascade. An essential oil high in carvacrol (Satureja khuzestanica, 93.9% carvacrol) significantly reduced plasma glucose concentrations in diabetic rats when given orally at 100 mg/kg/ day for 21 days (Shahsavari et al 2009).
Reproductive toxicity When Origanum vulgare oil was fed to pregnant mice for two weeks at 1,000 ppm (equivalent to
150 mg/kg), there was a related increase in the rate of embryonic cell death (Domaracky et al 2007). Satureja khuzestanica,
an essential oil consisting of 93.9% carvacrol, was given orally to pregnant rats during gestational days 0–15 at doses of 100, 500 or 1,000 ppm. There were no signs of maternal toxicity or teratogenicity at any dose, and in the two higher dose groups there
was a significant increase in the number of implantation and live fetuses, a positive outcome (Abdollahi et al 2003; Abdollahi,
private communication, 2004).
Acute toxicity Origanum oil acute oral LD50 in rats 1.85 g/kg; acute dermal LD50 in rabbits 480 mg/kg (Opdyke 1974 p. 945–946).
Antioxidant/pro-oxidant activity Origanum vulgare L. subsp. hirtum oil displayed antioxidant activity in chicken liver, muscle
tissue and egg yolk (Dorman et al 1995) and was significantly antioxidant (comparable with a-tocopherol or BHT) in three
different assays (Kusilic et al 2004). The oil scavenged DPPH radicals with an IC50 of 0.17 mg/mL (Bozin et al 2006). Thymbra capitata oil had more than double the antioxidant potency of BHT in sunflower oil (Miguel et al 2003b).
Carcinogenic/anticarcinogenic potential Origanum oil significantly induced glutathione S-transferase activity in mouse tissues
(Lam & Zheng 1991). Origanum onites oil (74.0% carvacrol, 7.2% linalool, 4.4% thymol) was not mutagenic in S. tymphimurium
strains TA98 and TA100 with or without S9, and strongly inhibited induced mutagenicity in the same strains (Ipek et al 2005). Thymbra capitata oil was not mutagenic in either the Bacillus subtilis rec-assay or the Salmonella/microsome reversion
assay (Zani et al 1991). Origanum vulgare L. subsp. hirtum oil is reported to be non-genotoxic and antigenotoxic (Bakkali et al
2006; Mezzoug et al 2007). An Origanum vulgare L. subsp. hirtum oil with 79.6% carvacrol caused complete cell death in two
human cancer cell lines,Hep-2 andHeLa, at 0.01% (Sivropoulou et al 1996). Carvacrol displays anticarcinogenic activity.
Drug interactions Antidiabetic or anticoagulant medication, because of cardiovascular effects, above. See Table 4.10B.
Oils from many origins may be offered as ‘oregano’ or ‘origanum’ oils. Wild marjoram oil (carvacrol CT) is chemically similar
to oregano oil. While most commercial oils are high in carvacrol, thymol chemotypes or thymol/carvacrol chemotypes
are also found, though this is unlikely to significantly affect the safety profile of the oil. There is a (non-commercial) chemotype
of Origanum onites, with 80–92% linalool.