Essential oils are one of the vital ingredients in aromatherapy, a hugely popular variety of alternative medicine that has seen a marked comeback in recent years. Aromatherapy uses ‘volatile’ oils and other substances extracted from plants to aid in the promotion of both physical and mental well-being in an individual.

Essential oils are extracted from plants, usually using distillation. The oils may be extracted from any section of the plant, including leaves, flowers, roots, resin and peel.

The oils are usually sold in small, glass bottles, but can be bought in a number of forms. Usually they are released into the air by heating over a candle, burned as incense, or it is even possible to put some on a piece of cloth so it naturally defuses into the air.

Alternatively, essential oils can ...