Organic oils and essential oils. Essential oils are considered by some to be the plants' hormones, and bearers of their life force. They can be used to treat a wide range of physical, mental and psychosomatic disorders. Their scent can affect both one's mood and psychological state. To have a good therapeutic effect, essential oils must be of the best quality. That is to say, they should come from plants that either grow wild in nature, or that are cultivated without the use of artificial fertilizers and pesticides. It is important that the plants are grown organically, as pesticides and substances from artificial fertilizers can end up in the oil. The height above sea level and the soil at the place of growth are also important for the quality of the oil. Essential oils have a very complex molecular structure and can contain many hundreds of chemical substances. The most common types of ingredients are alcohols, esters, ketones, phenols and aldehydes, and it is these substances that have been best investigated in terms of therapeutic effects. Aromatherapists believe that the essential oils penetrate the body and affect the mind and body, both via the olfactory organs and directly through the skin. It is assumed that the essential oils affect the central nervous system when inhaled and that they penetrate capillaries and cellular tissue when applied to the skin. The text is taken from Urtekilden (http://www.rolv.no) with their permission.