I have found that scientific explanations of what essential oils are can be heavy and convoluted. The best explanation I have come across is from Jen O’Sullivan’s book “French Aromatherapy Essential Oil Recipes & Usage Guide”:
“Essential oils are the life force of the plant they come from.
They are much like human blood in that they help to regulate the various functions of the plant and promote overall health of the plant. Just like the blood helps to oxygenate, regulate and heal our bodies, essential oils do the same for the plant they are sourced from. You may hear essential oils referred to as the volatile part of the plant. Volatile means a substance’s ability to leap into the air.
Essential oils are the fragrance you inhale when you walk through a pine forest or smell a rose.
Our bodies of composed of around 100 trillion cells. Essential oils are composed of around 40 million trillion molecules per single drop. This means that essential oil molecules are SUPER small (less than 500-300 Daltons or amu (atomic mass unit) in weight). All that science means this: the molecules of essential oils are able to pass through all of our tissues and directly into our cells. The body’s transportation system, along with the volatility of the oils, creates an extremely effective highway for these molecules to get into the entire body within minutes when placed anywhere on the exterior of the body.”
**For more details on what essential oils are you can also visit my talented friend Jessica over at My Own Little Circus.