When we inhale the aroma, messages are sent from the nose to the brain (via the Olfactory nerve). They reach the part of the brain that holds our instincts, emotions and memories. Thus a drop of oil can evoke moods and memories.
Messages are also sent to the endocrine system (hormones), which sends hormones to the relevant glands. Thus, oils can affect our hormones (for example, geranium).
As we smell, molecule also travels into the lungs. Some oils have an affinity with the lungs (for example, eucalyptus). When reaching the lungs, these oils have an impact. Eucalyptus will ease breathing, clear mucus and is excellent for Bronchitis.
Whilst in the lungs, the molecules continue their journey, penetrating the blood vessels. From there they travel through the blood circulation reaching the appropriate organs. Finally they exit the body through exhalation, perspiration and urination.
Absorption of essential oils through the skin
A molecule of the essential oil is sufficiently small and therefore can penetrate the skin and then the blood vessels. From there the drop reaches the various organs in our body.
Some oils have an affinity with certain organs; so the drops reach these chosen organs. For example, sweet orange has an affinity with the digestive system, where the drop of oil will eventually reach. Here it leaves its impact (aids digestion). Finally the drop continues its passage through the veins and exits the body through the digestive system or the skin (sweat).