While herbs have been shown to have anti-viral properties, essential oils or the chemical constituents of oils from various plants and bark have also been shown in clinical or laboratory studies to inhibit or kill viruses. A few of the more commonly studied essential oils include oregano, clove, cinnamon, eucalyptus, melaleuca (tea-tree), helichrysum, melissa, peppermint, rosemary, thyme, cypress, as well as citrus oils such as lemon, lime, grapefruit, and orange.
