Yarrow essential oil is a volatile oil including a chemical called proazulenes.
The dark blue essential oil, extracted by steam distillation of the flowers, is generally used as an anti-inflammatory or in chest rubs for colds and influenza. For a massage oil for inflamed joints, dilute 5-10 drops yarrow oil in 25ml infused St. John's wort oil. A chest rub can be made for chesty colds and influenza. Combine yarrow with eucalyptus, peppermint, hyssop, or thyme oil, diluting a total of 20 drops of oil in 25ml almond or sunflower oil.