Overview You may already know that oregano is an Italian herb commonly used in cooking. But it can also be made into a more concentrated herbal supplement, often called oregano oil. There are also oregano essential oils which have a much stronger concentration of the oregano plant than the herbal supplement. Oregano essential oil is made from the leaves of the oregano plant. Even though oregano is a well-known herb found in many kitchens, oregano herbal oils and oregano essential oils aren’t used for cooking. Rather, the essential oil is used both topically and through inhalation to treat specific health conditions. The herbal oil can be taken as an herbal supplement. Oregano oil contains chemical compounds, including phenolic glycosides (phenols). These compounds have antioxidant and antimicrobial properties. Phenols, such as carvacrol, cymene, terpinine, and thymol, account for much of the composition of oregano oil. It’s the phenols in oregano oil which may make it beneficial.

Side effects and risks Unlike the herb you cook with, commercially-prepared oregano oil is highly concentrated. It’s easy to take too much or to use it for too long. When used as directed, oregano oil should be safe. In too-high doses, it may have detrimental effects. This may be due in part to thymol, one of the phenols it contains. In high doses, thymol is a mild irritant which might affect the skin or internal organs. It can cause: nausea

vomiting

gastric distress

central hyperactivity (inappropriate talkativeness) Thymol may also be irritating or corrosive to the skin and eyes. Oregano oil should never be applied to broken skin or used on or near the eyes. Oregano oil may cause an allergic reaction in some people. If you’re allergic to oregano or to other plants in the Lamiaceae family, such as mint, sage, basil, and lavender, don’t use oregano oil. When used topically, diluted oregano essential oil may cause a skin rash, even in people who aren’t allergic to it. It’s important to check with your doctor before using oregano oil and to follow package directions exactly, whether you’re using the capsules or essential oil. There’s been no medical research done on oregano oil’s safety for children, or for pregnant or breastfeeding women. These populations shouldn’t use oregano oil. While data is lacking, there’s some concern that oregano oil may cause uterine contractions or miscarriage.

Proper dosage and use guidelines Medicinal dosages of oregano oil for people hasn’t been studied in-depth. Commercially-sold supplements and essential oils have recommended doses, established by their manufacturers. These take the amount of thymol and other phenols into account. It’s important not to exceed the recommended dosage given or to take oregano oil in any form, including on the skin, for more than several weeks. When using oregano essential oil, a little goes a very long way.One to two drops of diluted oil may not seem like much, but exceeding that dosage may cause adverse reactions to occur.

When to see your doctor Symptoms of oregano allergy can include rash, stomach distress, or trouble breathing. It’s especially important not to inhale oregano oil if you might be allergic to it. Doing so can cause inflammation of the airways and might quickly become dangerous. Chronic exposure to thymol may cause symptoms warranting a doctor’s visit. These include: fatigue

diarrhea

muscle pain

vertigo

headache

difficulty swallowing

excessive salivation