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Oregano

What is it?

Oregano is an herb with olive-green leaves and purple flowers. It grows 1-3 feet tall and is closely related to mint, thyme, marjoram, basil, sage, and lavender.

Oregano is native to warm western and southwestern Europe and the Mediterranean region. Turkey is one of the largest exporters of oregano. It now grows on most continents and under a variety of conditions. Countries known for producing high-quality oregano essential oils include Greece, Israel, and Turkey.

Outside of the U.S. and Europe, plants referred to as "oregano" may be other species of Origanum, or other members of the Lamiaceae family.

Oregano is taken by mouth respiratory tract disorders such as coughs, asthma, allergies, croup, and bronchitis. It is also taken by mouth for stomach disorders such as heartburn, bloating, and parasites. Oregano is also taken by mouth for painful menstrual cramps, rheumatoid arthritis, urinary tract disorders including urinary tract infections (UTIs), headaches, diabetes, bleeding after having a tooth pulled, heart conditions, and high cholesterol.

Oregano oil is applied to the skin for skin conditions including acne, athlete's foot, dandruff, canker sores, warts, wounds, ringworm, rosacea, and psoriasis; as well as for insect and spider bites, gum disease, toothaches, muscle and joint pain, and varicose veins. Oregano oil is also applied to the skin as an insect repellent.

In foods and beverages, oregano is used as a culinary spice and a food preservative.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for OREGANO are as follows:

Insufficient evidence to rate effectiveness for...

  • Parasites in the intestines. Some early research shows that taking 200 mg of a specific oregano leaf oil product (ADP, Biotics Research Corporation, Rosenberg, Texas) by mouth three times daily with meals for 6 weeks can kill certain types of parasites; however, these parasites usually do not require medical treatment.
  • Wound healing. Early research suggests that applying an oregano extract to the skin twice daily for up to 14 days after a minor skin surgery might reduce the risk of infection and improve scars.
  • Acne.
  • Allergies.
  • Arthritis.
  • Asthma.
  • Athlete's foot.
  • Bleeding disorders.
  • Bronchitis.
  • Cough.
  • Dandruff.
  • Flu.
  • Headaches.
  • Heart conditions.
  • High cholesterol.
  • Indigestion and bloating.
  • Muscle and joint pain.
  • Painful menstrual periods.
  • Urinary tract infections (UTI).
  • Varicose veins.
  • Warts.
  • Other conditions.
More evidence is needed to rate oregano for these uses.

How does it work?

Oregano contains chemicals that might help reduce cough and spasms. Oregano also might help digestion by increasing bile flow and fighting against some bacteria, viruses, fungi, intestinal worms, and other parasites.

Are there safety concerns?

Oregano leaf and oregano oil are LIKELY SAFE when taken in amounts commonly found in food. Oregano leaf is POSSIBLY SAFE when taken by mouth or applied to the skin appropriately as medicine. Mild side effects include stomach upset. Oregano might also cause an allergic reaction in people who have an allergy to plants in the Lamiaceae family. Oregano oil should not be applied to the skin in concentrations greater than 1% as this might cause irritation.

Special precautions & warnings:

Pregnancy and breast-feeding: Oregano is POSSIBLY UNSAFE when taken by mouth in medicinal amounts during pregnancy. There is concern that taking oregano in amounts larger than food amounts might cause miscarriage. There is not enough reliable information about the safety of taking oregano if you are breast feeding. Stay on the safe side and avoid use.

Bleeding disorders: Oregano might increase the risk of bleeding in people with bleeding disorders.

Allergies: Oregano can cause reactions in people allergic to Lamiaceae family plants, including basil, hyssop, lavender, marjoram, mint, and sage.

Diabetes: Oregano might lower blood sugar levels. People with diabetes should use oregano cautiously.

Surgery: Oregano might increase the risk of bleeding. People who use oregano should stop 2 weeks before surgery.

Are there interactions with medications?

Moderate
Be cautious with this combination.
Medications for diabetes (Antidiabetes drugs)
Oregano might decrease blood sugar. Diabetes medications are used to lower blood sugar. In theory, taking some medications for diabetes along with oregano might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.

Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others..
Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Oregano might slow blood clotting. In theory, taking oregano along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), dabigatran (Pradaxa), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others..

Are there interactions with herbs and supplements?

Copper
Oregano might interfere with copper absorption. Using oregano along with copper might decrease the absorption of copper.
Herbs and supplements that can lower blood sugar
Oregano might lower blood sugar. In theory, taking oregano along with herbs and supplements that also lower blood sugar might reduce blood sugar levels too much. Some herbs and supplements that might lower blood sugar include alpha-lipoic acid, bitter melon, chromium, devil's claw, fenugreek, garlic, guar gum, horse chestnut, Panax ginseng, psyllium, Siberian ginseng, and others.
Herbs and supplements that might slow blood clotting
Using oregano along with herbs that can slow blood clotting might increase the risk of bleeding in some people. These herbs include angelica, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, horse chestnut, red clover, turmeric, and others.
Iron
Oregano might interfere with iron absorption. Using oregano along with iron might decrease the absorption of iron.
Zinc
Oregano might interfere with zinc absorption. Using oregano along with zinc might decrease the absorption of zinc.

Are there interactions with foods?

There are no known interactions with foods.

What dose is used?

The appropriate dose of oregano depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for oregano (in children/in adults). Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Other names

Carvacrol, Dostenkraut, European Oregano, Huile d'Origan, Marjolaine Bâtarde, Marjolaine Sauvage, Marjolaine Vivace, Mediterranean Oregano, Mountain Mint, Oil of Oregano, Oregano Oil, Organy, Origan, Origan Européen, Origani Vulgaris Herba, Origano, Origanum, Origanum vulgare, Phytoprogestin, Spanish Thyme, Thé Sauvage, Thym des Bergers, Wild Marjoram, Winter Marjoram, Wintersweet.

Methodology

To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.

References

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Last reviewed - 06/13/2016