5 oregano oil side effects you should be aware of

What is oregano oil?

Oregano, also known as Origanum vulgare, is a flowering plant from the mint family. An everyday use of this herb is to flavour food.

Originally from Europe, it now grows everywhere. Oregano has been popular since ancient Greek and Roman civilizations used it for medicinal purposes. Oregano is named after the Greek words “oros”, meaning mountain, and “ganos”, meaning joy or delight.

Topically applied oregano essential oil can be mixed with a carrier oil. Remember, it should not be consumed orally. Carbon dioxide or alcohol can be used to extract Oregano oil extract. However, it’s commonly available as a supplement and can often be found in pill or capsule form.

Oregano contains compounds called phenols, terpenes, and terpenoids. They have powerful antioxidant properties and are responsible for their fragrance [1].

Among the phenols in oregano, carvacrol is the most abundant. There is evidence that it stops the growth of a variety of bacteria. Besides being an antifungal, Thymol also supports immunity and protects against toxins. 

Last but not least, Rosmarinic acid is powerful antioxidant that can protect against damage caused by free radicals [2]. These compounds are thought to contribute to oregano’s many health benefits.

As mentioned, oregano is an Italian herb frequently used in cooking but it can also be processed into a more potent herbal supplement, often called oregano oil [3]. There are also oregano essential oils with a much stronger concentration of the oregano plant than the herbal supplement.

Oregano essential oil is extracted from its leaves. Despite being a common herb in many kitchens, oregano herbal oils and essential oils aren’t used to cook with.

Specific health conditions are treated using the essential oil topically and through inhalation. The herbal oil can be used as an herbal supplement.

Forms of oregano oil

The extract of oregano oil is a herbal supplement. There are three forms available: pills, softgel capsules and supplements.

It is possible to take the capsules orally, or cut them open and apply them to the skin, if they are not full strength. As oregano oil is very powerful, these are usually diluted with other ingredients. 

Forms of oregano oil

It is possible to use the essential oil topically after diluting it. Take essential oils orally only after consulting a certified aromatherapist.

Some essential oils are toxic, while others have different qualities. Steam can also be used to inhale oregano essential oil as a vapour. It can be done by placing one or two drops in a steaming bowl or vaporizer.

Uses and applications

Research on oregano has mostly been conducted in vitro, on animals, or in small human trials. Despite the fact that some of this research is promising, it is not conclusive proof that oregano oil is effective. However, this product has a wide range of applications.

In cooking or as an herbal supplement for:

  • Bacterial infections (E. coli)
  • Parasitic infections
  • Small intestinal bacterial overgrowth (SIBO)
  • Urinary tract infections (UTIs)
  • Viruses, likehe norovirus (stomach virus) or upper respiratory infections
  • Yeast infections (Candida)

The essential oil as a vapour for:

  • Asthma
  • Bronchitis
  • Cough
  • Respiratory infections

The diluted essential oil topically for:

  • Acne
  • Bug bites
  • Dandruff
  • Poison ivy
  • Topical infections

Risks and side effects

Commercially prepared oregano oil is highly concentrated, unlike the herb you cook with. Taking too much or using it for too long is easy. 

Oregano oil should be safe when used as directed. Taking too much of it can be harmful. One of its phenols, thymol, may contribute to this. Thrymol is a mild irritant that might affect the skin or internal organs in high doses.

One potential side effect of oregano oil is gastrointestinal upset. This can include symptoms such as nausea, vomiting, and diarrhea [4]. Oregano oil can also cause allergic reactions in some people, including skin rash, hives, and difficulty breathing [5]. 

If you experience any of these symptoms after taking oregano oil, you should stop using it and seek medical attention. Oregano oil can also interact with certain medications, including blood thinners, diabetes medications, and nonsteroidal anti-inflammatory drugs (NSAIDs) [6]. If taking any of these medications, you should talk to your doctor before using oregano oil.

It is also important to note that oregano oil is not recommended for use in pregnant or breastfeeding women, as there is not enough research available to determine its safety in these groups [7]. If you are pregnant or breastfeeding, it is best to avoid using oregano oil or to consult with your healthcare provider before using it.

In addition to the above side effects, oregano oil may also cause skin irritation when applied topically [8]. If you experience skin irritation after using oregano oil, you should wash the affected area with soap and water and stop using the oil.

There has been no medical investigation on the safety of oregano oil for children, pregnant women or breastfeeding mothers. It is not recommended to use oregano oil on these populations. Despite the lack of data, uterine contractions or miscarriages have been linked to oregano oil.

Guidelines for proper dosage and use

A detailed study of the medical dosages of oregano oil for people has not been conducted. There are recommended doses for supplements and essential oils sold commercially. Thymol and other phenols are taken into account in these calculations.

Oregano oil should not be taken in excess of the recommended dosage or applied topically. It only takes a few drops of oregano essential oil to make a big difference. A few drops of diluted oil may not seem like much, but exceeding that dosage can have harmful effects.

Guidelines for proper dosage and use of oregano oil

Should I see my doctor?

A rash, stomach distress, or difficulty breathing may be symptoms of an oregano allergy. If you are allergic to oregano oil, you should not inhale it. As a result, inflammation of the airways can quickly become dangerous.

The effects of chronic exposure to thymol may warrant a doctor’s visit. These include:

  • Diarrhea
  • Difficulty swallowing
  • Excessive salivation
  • Fatigue
  • Muscle pain
  • Vertigo

Many people claim that oregano oil can soothe symptoms and cure medical conditions. There is, however, very little evidence to support these claims.

Whether you decide to take oregano oil as a supplement or essential oil, follow dosage directions strictly and consult your doctor before use. You should always dilute essential oils because they are much stronger than supplements. 

Babies, children, pregnant women and breastfeeding mothers shouldn’t use oregano oils.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6508890/
[2] https://www.ncbi.nlm.nih.gov/pubmed/25808312
[3] https://www.healthline.com/nutrition/6-oregano-benefits
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5958894/
[5] https://pubmed.ncbi.nlm.nih.gov/30000904/
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3918264/
[7] https://pubmed.ncbi.nlm.nih.gov/12807304/
[8] https://www.takingcharge.csh.umn.edu/are-essential-oils-safe

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