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Overview: Eucalyptus is used for many reasons, but its benefits are not well defined. It is available as a dietary supplement that can be swallowed and as an essential oil that may be mixed and then applied to the skin or inhaled as aromatherapy. Common side effects include heartburn, rash, nausea, vomiting, and an upset stomach. Serious side effects are rare but include allergic skin reactions. Before using any form of eucalyptus, make sure to tell your health care provider about any health conditions you have or medicines you are taking.

Uses

What is eucalyptus used for?

Eucalyptus (Eucalyptus globulus) is used for many reasons, but its benefits are not well defined. Some common reasons for using eucalyptus include the following.

Note: The FDA has not reviewed eucalyptus for safety and effectiveness. Learn more about dietary supplements here. Learn more about essential oils and aromatherapy here.

How does eucalyptus work (mechanism of action)?

Eucalyptus refers to a tree called Eucalyptus globulus. Dietary supplements containing eucalyptus are made from its leaves. Although these supplements are used for various reasons, it is not clear if or how they may work for any purpose.

Most products that contain eucalyptus, including creams, ointments, and mixtures to add to bathwater, are made from its essential oil. Eucalyptus essential oil is made from the leaves and small branches of the tree. But the chemicals in eucalyptus essential oil are different from those in the dried leaves. Essential oils are made by heating up the leaves until certain chemicals, called volatile aromatic compounds, are released. The main chemical in eucalyptus essential oil, eucalyptol, gives the distinctive smell of eucalyptus. Pure eucalyptus essential oil is toxic and should not be taken by mouth.

Eucalyptus essential oil can be inhaled as aromatherapy through a diffuser or by mixing it in boiling water and inhaling the steam. The smell of eucalyptus may be soothing for some people, but it is not clear if it is beneficial for any specific use. Although the essential oil is sometimes added to bathwater to help with sore muscles, its benefits for this use are also not well defined.

There has been some interest in using eucalyptus essential oil to treat skin infections. But only the pure oil can kill bacteria that cause infections. Pure eucalyptus essential oil causes severe irritation when applied to the skin and should be diluted (mixed with something else, such as another oil) before use. Once it is diluted, it will not be able to kill bacteria. Do not rely on eucalyptus essential oil to treat or prevent any type of skin infection.

Eucalyptus may act as an expectorant and help break up the mucus in your nose and lungs when you are sick, making it easier to breathe. But most throat lozenges that claim to contain eucalyptus only contain eucalyptus flavoring or scent. It is not clear if inhaling eucalyptus oil as aromatherapy can help with a cough or sore throat.

Herbal products, such as eucalyptus, naturally contain many chemicals. The amounts of each chemical in a specific eucalyptus product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.

How should I store eucalyptus?

You should store eucalyptus according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of eucalyptus?

The most common side effects of eucalyptus are listed below. These side effects may vary depending on the way you are using it, the dose you are taking, or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.

  • Heartburn
  • Nausea or vomiting
  • Rash
  • Upset stomach

There may be other side effects of eucalyptus that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of eucalyptus?

While less common, the most serious side effects of eucalyptus are described below, along with what to do if they happen.

Severe Allergic Reactions. Eucalyptus may cause allergic reactions, which can be serious. Stop using eucalyptus and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Skin Reactions. Eucalyptus essential oil can cause skin reactions, such as rashes, blisters, and burns. This risk seems to be higher in people who use products that contain high concentrations of eucalyptus essential oil. Pure eucalyptus essential oil should be diluted before it is applied to the skin. In some people, these skin reactions may be caused by an allergy to eucalyptus (contact dermatitis). Stop using eucalyptus essential oil and contact your health care provider right away if you have a skin reaction.

Warnings & Precautions

Who should not use eucalyptus?

Allergies to Ingredients. People who are allergic to any of the following should not use eucalyptus.

  • Eucalyptus
  • Eucalyptus globulus
  • Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific eucalyptus products they stock.

What should I know about eucalyptus before using it?

Eucalyptus leaves are available as a dietary supplement. Eucalyptus essential oil is available for use as aromatherapy. These products cannot be marketed to treat or cure a disease.

Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.

Keep eucalyptus out of the reach of children. Children under 3 years of age may be at a greater risk of having side effects from eucalyptus products. Before using eucalyptus for your child, speak with a health care provider about the possible risks.

Eucalyptus dietary supplements, which are swallowed, contain the dried leaves of the tree. Eucalyptus essential oils, which are diluted and then applied to the skin or inhaled as aromatherapy, contain specific chemicals taken from the leaves and branches. Different forms contain different amounts of the chemicals that are naturally found in the plant, causing different effects on the body.

Eucalyptus essential oil is for use on the skin only. Drinking eucalyptus essential oil can cause serious health problems. Do not take eucalyptus essential oil by mouth. Keep it away from your mouth and eyes. If you get eucalyptus essential oil in your eyes, wash your eyes right away with water.

Eucalyptus essential oil may be added to other products that are applied to the skin. But some eucalyptus essential oil products contain 100% pure eucalyptus essential oil. Pure eucalyptus essential oil can cause blisters and burns and should not be applied directly to your skin. It must be mixed before use. Most products recommend mixing about 3 drops of the oil into cream, lotion, or another oil. Follow the instructions on the product label.

Herbal products, such as eucalyptus, naturally contain many chemicals. The amount of each chemical in a specific eucalyptus product can vary for many reasons, including the area where the tree was grown, the weather during growth, the time of year when it was harvested, and the way that the leaves were processed after they were harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.

The FDA has not tested eucalyptus products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here. There are no third-party organizations that test essential oils to confirm that their labels are accurate and that they do not contain any harmful chemicals.

What should I tell my health care provider before using eucalyptus?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if eucalyptus is right for you.

In particular, make sure that you discuss any of the following.

Large Wounds or Serious Burns. Talk to your health care provider before applying eucalyptus products or adding eucalyptus to bathwater if you have a large wound or a serious burn. It may not be safe to use eucalyptus on these types of wounds. They may need other treatment.

Sensitive Skin. Eucalyptus essential oil can cause skin irritation and skin reactions, especially in people who have sensitive skin. If you have sensitive skin, talk to your health care provider before using eucalyptus essential oil.

Other Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Asthma
  • Other lung or breathing problems
  • Seizures (in children, especially those younger than 3 years)

Pregnancy. It is not known if or how eucalyptus could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if eucalyptus passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does eucalyptus interact with foods or drinks?

There are no known interactions between eucalyptus and foods or drinks.

It is unknown if drinking alcohol will affect eucalyptus.

Does eucalyptus interact with medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

The interactions between eucalyptus and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with eucalyptus is incomplete. Always check with your health care provider before taking eucalyptus with any medicines.

Overdose/Missed Dose

What should I do if I accidentally use too much eucalyptus?

If you or someone else has used too much eucalyptus, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Eucalyptus leaves are available as a dietary supplement. Read the product label closely and speak with a health care provider about how to take eucalyptus safely. Do not take double or extra doses, even if you miss a dose.

Eucalyptus essential oil may be used as aromatherapy or applied to the skin, but it must be mixed (diluted) before use. Follow the instructions on the product label. Do not take eucalyptus essential oil by mouth.