A good number of essential oils are sedative in effect - that is, they have a calming effect, particularly on the central nervous system.
Among the most effective sedative oils are Camomile, Lavender, Bergamot and Neroli. Others are Rose, Benzoin, Clary Sage, Hyssop, Jasmine, Marjoram, Melissa and Sandalwood and there are still others, though these may be less used.
The most effective means of using these oils are in massage and in baths, most particularly before sleeping, when they will help to prevent insomnia. The choice of a particular oil will depend very much on the individual for whom it is to be used; on that person's preferences for a particular aroma, and on their situation at the time. Every one of the oils mentioned has many other properties, in addition to being sedative, and one or more of these may determine the final choice from among the wide range of oils available.