Oregano (Origanum vulgare)

Category

Herbs & Supplements

Synonyms

Dostenkraut, Mediterranean oregano, mountain mint, oil of oregano, oregano oil, Origani vulgaris herba, origanum, wild marjoram, Zaatar.

Background

Oregano is a perennial herb. The leaves, stems and flowers are used medicinally. Oregano has been recognized for its aromatic properties since ancient times. In ancient Greece, oregano was called 'Joy of the Mountain' and was considered a symbol of joy and happiness. Ancient Egyptians considered Origanum species to be sacred to the god Osiris, and wove it into crowns or wreaths worn during rituals.

Oregano is commonly used as a food flavoring and preservative. Traditionally, oregano has been used to treat respiratory and gastrointestinal disorders and menstrual irregularities. Modern herbalists recommend topical application of oregano oil for the treatment of infection.

Early study suggests that oregano may have antiparasitic, antifungal, antioxidant, antibacterial and insect repellent activities. There is limited scientific evidence to support any of these suggested uses for oregano.

Evidence

DISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Parasites: Early study shows that taking oregano by mouth may help treat parasites. Further research is needed to confirm these results.
Grade: C

Tradition

WARNING: DISCLAIMER: The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Abortion inducing, acne, antibacterial, antifungal, antimutagenic, antioxidant, antiparasitic, anti-thrombin, arthritis, asthma, athlete's foot (topically), bloating, bronchitis, canker sores (topically), carminative, colds, cough, croup, dandruff, diaphoretic, dysentery, dysmenorrheal (orally), dyspepsia, expectorant, flavoring, food preservative, gastrointestinal disorders, gum disease (topically), headaches (orally), heart conditions (orally), high blood sugar, increased insulin sensitivity, insect and spider bites, menstrual stimulant (orally), menstrual irregularities, metorrhagia (painful menstruation), mild tonic (orally), muscle pain, phytoestrogenic, preservative, psoriasis, respiratory disorders, rheumatoid arthritis (orally), ringworm (topically), rosacea, seborrhea, superficial and systemic infections (topically), toothache, ulcers, urinary tract infections, varicose veins, warts weak, insect repellent.

Dosing

Adults (over 18 years old)

There is no proven effective dose for oregano. Oregano has been taken in doses of 200 milligrams of emulsified oil three times daily with meals for six weeks for the treatment of enteric parasites. As a dietary supplement, two capsules (dose unknown) once or twice daily has been recommended with meals, or a few drops of oil of oregano can be added to milk or juice.

Oregano oil has also been applied topically (on the skin), and shampoos and teas (gargle, mouthwash) are commercially available. For use as a bath additive, 100 grams of dried oregano leaf may be steeped in one liter of water for 10 minutes, strained and added to a full bath.

Children (under 18 years old)

There is no proven effective dose for oregano in children.

Safety

DISCLAIMER: Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.

Allergies

Avoid in individuals with a known allergy or hypersensitivity to oregano. Possible cross-sensitivity with other herbs from the Lamiaceae family including hyssop (Hyssopus officinalis), basil (Ocicum basilicum), marjoram (Origanum majorana), mint (Mentha piperita), sage (Salvia officinalis), and lavender (Lavendula officinalis).

Itching and swelling of the lips and tongue, difficulty speaking and breathing, and face swelling have been reported following the ingestion of pizza containing oregano.

Side Effects and Warnings

Based on historical use, it appears that oregano is well tolerated in recommended doses. However, there are no available reliable clinical trials demonstrating safety or efficacy of a particular dose or for a recommended treatment duration.

Oregano may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

Pregnancy & Breastfeeding

Oregano is not recommended at doses above those normally found in food due to a lack of available scientific evidence. An over-the-counter product containing oregano as one of four herbal ingredients (Carachipita® - pennyroyal (Mentha pulegium), yerba de la perdiz (Magiricarpus pinnaus) and guaycuru (Statice brasiliensis)) has been linked with case reports of induced abortion.

Interactions

Interactions with Drugs

Oregano may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

Oregano may have phytoestrogenic effects. Interactions with hormonal agents are theoretically possible.

Oregano may have anti-thrombin effects. Interactions with anticoagulants are theoretically possible.

Interactions with Herbs and Dietary Supplements

Oregano may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Because oregano contains estrogen like chemicals, the effects of other agents believed to have estrogen-like properties may be altered

Oregano may have anti-thrombin effects. Interactions with anticoagulants are theoretically possible.

Attribution

This information is based on a systematic review of scientific literature, and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Heather Boon BScPhm, PhD (University of Toronto); Jo Thompson Coon, PhD (Peninsula Medical School); Nicole Giese, MS (Boston University); Dana A. Hackman, BS (Northeastern University); David Kiefer, MD (University of Arizona); Lisa Scully, PharmD (University of Rhode Island); Isabell Syelsky, PharmD (Northeastern University); Brian Szczechowski, PharmD (Massachusetts College of Pharmacy); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Wendy Weissner, BA (Natural Standard Research Collaboration).

Bibliography

DISCLAIMER: Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

Bagamboula CF, Uyttendaele M, Debevere J. Antimicrobial effect of spices and herbs on Shigella sonnei and Shigella flexneri. J Food Prot 2003;66(4):668-673.

Burt SA, Reinders RD. Antibacterial activity of selected plant essential oils against Escherichia coli O157:H7. Lett Appl Microbiol 2003;36(3):162-167.

Chami F, Chami N, Bennis S, et al. Evaluation of carvacrol and eugenol as prophylaxis and treatment of vaginal candidiasis in an immunosuppressed rat model. J Antimicrob Chemother 2004;54(5):909-914.

Chami F, Chami N, Bennis S, et al. Oregano and clove essential oils induce surface alteration of Saccharomyces cerevisiae. Phytother Res 2005;19(5):405-408.

Chorianopoulos N, Kalpoutzakis E, Aligiannis N, et al. Essential oils of Satureja, Origanum, and Thymus species: chemical composition and antibacterial activities against foodborne pathogens. J Agric Food Chem 2004;52(26):8261-8267.

Ciganda C, Laborde A. Herbal infusions used for induced abortion. J Toxicol Clin Toxicol 2003;41(3):235-239.

Dorman HJ, Deans SG. Antimicrobial agents from plants: antibacterial activity of plant volatile oils. J Appl Microbiol 2000;88(2):308-316.

Exarchou V, Nenadis N, Tsimidou M, et al. Antioxidant activities and phenolic composition of extracts from Greek oregano, Greek sage, and summer savory. J Agric Food Chem 2002;50(19):5294-5299.

Force M, Sparks WS, Ronzio RA. Inhibition of enteric parasites by emulsified oil of oregano in vivo. Phytother Res 2000;14(3):213-214.

Giordani R, Regli P, Kaloustian J, et al. Antifungal effect of various essential oils against Candida albicans. Potentiation of antifungal action of amphotericin B by essential oil from Thymus vulgaris. Phytother Res 2004;18(12):990-995.

Goun E, Cunningham G, Solodnikov S, et al. Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia 2002;73(7-8):692-694.

Lambert RJ, Skandamis PN, Coote PJ, et al. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. J Appl Microbiol 2001;91(3):453-462.

Marino M, Bersani C, Comi G. Impedance measurements to study the antimicrobial activity of essential oils from Lamiaceae and Compositae. Int J Food Microbiol 2001;67(3):187-195.

Nevas M, Korhonen AR, Lindstrom M, et al. Antibacterial efficiency of Finnish spice essential oils against pathogenic and spoilage bacteria. J Food Prot 2004;67(1):199-202.

Rivera JO, Hughes HW, Stuart AG. Herbals and asthma: usage patterns among a border population. Ann Pharmacother 2004;38(2):220-225.

Talpur N, Echard B, Ingram C, et al. Effects of a novel formulation of essential oils on glucose-insulin metabolism in diabetic and hypertensive rats: a pilot study. Diabetes Obes Metab 2005;7(2):193-199.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.