Are There Any Side Effects of Oregano?

Oregano is a medicinal plant. It is used for the disorders of respiratory tract such as bronchitis croup, asthma and coughs. It is also useful for gastrointestinal disorders (bloating and heartburn), urinary tract infections, heart conditions and headaches. There are various health benefits and medicinal uses of oregano. In addition to this, there are various side effects of oregano which are discussed below in this article. Some of the oregano plant side effects include skin irritations, skin rashes, headaches, vomiting, nausea and others. Read on to know more.

Side effects of Oregano

Oregano is likely to be safe when taken in appropriate amounts and it is possibly safe when taken orally or applied on the skin in the medicinal amounts. Some of the mild side effects of oregano include the following:

  • Upset stomach.
  • Allergic reaction:

    Oregano is also known to cause allergic reactions in individuals who are allergic to plants (Lamiaceae family).

Side effects of oregano tea:

  • Pregnancy problems:

    Oregano might reduce the ability of iron absorption in the body. This can also cause miscarriage and other problems during pregnancy.

  • Skin irritations:

    Drinking oregano tea might cause potential skin irritations and rashes. Individuals who are allergic to mint family herbs may also show adverse reactions after taking oregano tea.

  • Vomiting and stomach irritation:

    Oregano spice has lingering and bitter taste because of this and possible allergic reactions to the mint family plants some individuals may experience vomiting and stomach irritation after drinking the tea of oregano.

  • Stimulant:

    Oregano acts as a stimulant and it might cause increased perspiration and heart rate. This is one of the reasons why individuals drink oregano tea to treat the symptoms of cold and flu. However, over consumption of oregano tea might cause adverse side effects on an individual.

Side effects of oregano oil:

  • Allergic reactions:

    Individuals including oregano oil may experience some side effects after using it. Some of the symptoms of allergic reaction after using oregano oil include facial swelling, itching, skin rash and/or difficulty speaking, swallowing or breathing. Individuals with sensitive skin might develop symptoms of irritation after applying oregano oil. This condition can be avoided by diluting oregano oil with olive oil or other essential oil which is less irritating and soothing to the skin. Thus, individuals experiencing any of the allergic reactions or other after using oregano oil need to consult their doctor immediately.

  • Some of the other symptoms of oregano oil side effects include dizziness, nausea and headache. This occurs when oregano oil causes the death of harmful bacteria all at once. This can be prevented by drinking water in larger amounts.


  • Pregnancy:

    Possibly oregano is unsafe when taken orally in the medicinal amounts by pregnant women. There is a concern that taking oregano in larger amounts might cause miscarriage. Thus, it is best to avoid its use during pregnancy.

  • Breast-feeding or nursing:

    The safety on the use of oregano while breast-feeding or nursing is not enough known. The compounds can pass through the breast milk into the infants and can adverse side effects.

  • Allergies:

    Oregano plant can cause adverse reactions in individuals allergic to the plants of Lamiaceae family including sage, mint, marjoram, lavender, hyssop and basil.


Scientific research has studied the following doses of oregano plant:

  • Intestinal parasites:

    For treating intestinal parasites, it is recommended to take about 200 mg of oregano oil 3 times daily for six weeks.

The above article discusses about the side effects of oregano tea and oil. Individuals taking oregano need to consult their physician before using this oregano or its supplements. Pregnant and nursing women must avoid the use of oregano due to its ability to reduce iron absorption.

Besides side effects, oregano also has some health benefits. You can also read our another article Benefits of Oregano.

Comments are closed.