What are essential oils used for?

Essential oils are: used for aromatherapy.

Many uses: Essential oils can be used topically, via a diffuser, inhaled directly nasally/orally or ingested and can be used for a multitude of purposes. They can be helpful for anxiety, focus, attention, sleep as well as muscle pain, skin conditions and even for PMS or menopausal symptoms. You need to make sure that you use a high quality oil like doTerra and that you work with a knowledgeable provider.

Anything apparently: By definition, "alternative" is different than modern western medicine. Generally any drug, herb, treatment, or oil that stands up to rigorous scientific scrutiny is included in modern medicine. Many alternative practices, oils etc do not stand up to scientific scrutiny and cannot be shown to work. 'course the people who sell them make big $$$. Check https://nccih.nih.gov/ for research