Whenever you see a spa treatment that is called aromatherapy, it means that therapeutic-grade essential oils are being use. Usually a few drops of essential oils are added to carrier oils like sweet almond, jojoba or grapeseed oil.
Although it's called an "oil," the consistency of essential oil is not fatty; it's more like water. Essential oils are highly volatile and readily evaporate in open air, releasing a strong scent. Some of the most popular, well-known essential oils are lavender, chamomile, peppermint, eucalyptus, rose-geranium, and lemon.
Not all essential oils are therapeutic. Lower-grade essential oils are used to flavor foods or used in inexpensive toiletries. You might also see lower quality essential oils in health food stores.
A therapeutic-grade essential oil should list the botanical species, the producing organ from the plant (root, leaves, etc.), and the chemotype (chemical composition). For instance, common thyme has several different chemotypes, depending on where it was grown and the time of year it was harvested.
Besides having pleasant scents that relax you or lift your mood, essential oils also have other qualities. They can prevent or combat infection and kill bacteria. They are also considered to be "adaptogenic, which means they are flexible in response to specific needs.
Essential oils also have benefits for your body, supporting organ systems and promoting the health of your skin. They nourish the tissues, encourage cell growth, and help the body detoxify.
The ancient Egyptians were the first to discover the therapeutic use of plants, infusing aromatic plants into oils to create perfumed oils. Greeks and Romans did this as well. True essential oils obtained by steam distillation and other means were widely used in medicine from the late 17th to the late 19th century, then fell out of favor except for use in perfumes.
The "rediscovery" of essential oils as medicine began in the 1920s, when a French chemist, Dr. Maurice Gattefosse, burned his hand and successfully treated it with essential oil of lavender. He is the one who coined the term "aromatherapy."