Exploring science's new biological understanding of essential oils and their advantages over synthetic drugs, renowned aromatherapist Kurt Schnaubelt reveals how the effectiveness of essential oil treatments stems from our common biochemical and cellular heritage with plants. He explains how essential oils preserve a plant's complex natural life-supporting and immune-building qualities, developed through millions of years of interaction with animals and humans. Reviewing recent research in molecular, cellular, and evolutionary biology, he shows how the multilayered activity of plant essences helps maintain the integrity of our genetic code--the reason why pathogens cannot develop resistance toward essential oils as they do with antibiotics and antivirals--making essential oils a more effective and sustainable form of treatment for a variety of health problems. Laying to rest old arguments over essential oils' alleged toxicity and whether they can be ingested or used undiluted, Schnaubelt presents simple recipes and protocols for treating and preventing common ailments, such as colds, flu, herpes, and candida, as well as for pain management. Offering new essential oil treatment opportunities for hepatitis, osteoporosis, liver detoxification, and the prevention of UV damage and melanoma, he shows how essential oils can also ameliorate the debilitating side effects of chemotherapy and other cancer treatments as well as how even home use of essential oils for relaxation or skin care can help build one's immunity and overall well-being.