Eucalyptus Essential Oil is probably most well known for its wonderful benefits for respiratory applications including helping to ease congestion and pressure, colds, flu, fever and bronchitis. It's also a great essential oil to use in massage or other topical blends to ease muscular pain and arthritis. Eucalyptus essential oil is obtained from fresh leaves of the tall, evergreen eucalyptus tree (Eucalyptus globulus, or less common). The essential oil is colorless and has a distinctive taste and odor. The potent medicinal benefits of eucalyptus oil are due to a compound called eucalyptol, which has antimicrobial properties. The oil is used in a variety of over-the-counter drugs including rubs, inhalers, liniments, rash creams, and mouthwashes.