What is it? Overview Usage Side Effects and Warnings

What are Eucalyptus?

The eucalyptus tree originated in Australia and Tasmania, but has now been spread to all other inhabited continents. There are many different varieties of eucalyptus, with somewhat differing constituents. The most common type used medicinally is eucalyptus globules. Its essential oil contains eucalyptol (cineol or cineole).

Eucalyptus oil has long history of use as a topical antiseptic. It has also been used as a lozenge or inhalation therapy for asthma, cough, sore throat, and other respiratory conditions.

A standardized combination of cineol from eucalyptus, d-limonene from citrus fruit, and alpha-pinene from pine has been studied for effectiveness in a variety of respiratory conditions. These oils are all in a chemical family called monoterpenes, and for this reason the combined treatment is called “ essential oil monoterpenes .” This combination is discussed in a separate article of that name. Other combination therapies containing eucalyptus oil are discussed in the article titled Aromatherapy .

Eucalyptus oil or its constituents taken alone have undergone only limited study. It appears to be most promising as a treatment for the common cold. However, concerns about safety have limited its use.

In a double-blind, placebo-controlled study of 152 people, use of cineol at...

Safety Issues

Internal use of eucalyptus oil at appropriate doses by healthy people can cause nausea, heartburn, vomiting, diarrhea, and skin rash. 1 Excessive dosages can be fatal, especially to children. Inhalation of the oil can exacerbate asthma in some people. Application of cineole to the entire body resulted in severe nervous system poisoning in a 6-year-old child. 2 In general, eucalyptus oil should not be used by young children, pregnant or nursing women, or people with severe liver or kidney disease.

Although no drug interactions of eucalyptus are firmly documented, there are theoretical reasons to believe it could interact with a number of medications, either raising or lowering their levels. 3 Therefore, people taking any oral or injected medication that is...