Eucalyptus oil, also known as eucalyptol, is steam-distilled from the twigs and long leathery leaves of the eucalyptus tree. Eucalyptus folium contains the dried leaves of older Eucalypti globulus trees. The leaves are collected after the tree has been cut down and allowed to dry in the shade. The primary component of eucalyptus oil is the volatile substance 1,8-cineol (cineole). Oil preparations are standardized to contain 80% to 90% cineole. Eucalyptus is used internally and externally as an expectorant, and to treat infections and fevers. It’s also used topically to treat sore muscles and rheumatism. A topical combination of eucalyptus and peppermint shows promise as an analgesic. Here’s an article that will explain more of its uses and benefits.