While the body of scientific research being conducted on essential oil effectiveness is still growing, there’s no disputing the healing properties of plants. Many contain compounds that fight harmful bacteria, viruses, and fungi, and still others contain constituents that ease pain, ward off inflammation, diminish depression, and perform a variety of other useful functions.

Essential oils and the plants from which they are derived have long been used in pharmaceuticals and body-care products. Even modern drugs contain active

ingredients derived from plants, or they use chemical copies of those constituents.

Essential oils are made up of tiny molecules that easily penetrate the skin, lungs, and other body systems, quickly making their way into the bloodstream. For instance:

When you add a few drops of lavender oil to a bedtime bath, its molecules are absorbed two ways: Steam from the hot water delivers them to your respiratory system, and your skin absorbs the molecules as it makes contact with them.
When you apply essential oil to your body, the molecules are absorbed rapidly. In some cases, lymph and blood flow increase, helping provide pain relief and/or promote healing. In other cases, they provide a cleansing effect or block bacteria; others help speed up detoxification.
When you inhale an essential oil, microscopic molecules travel into your nostrils and pass nerve receptors before being drawn into nasal mucus, where they are dissolved and taken up by your olfactory receptor cells. Once activated, these cells signal the olfactory bulb to send a message to the part of your brain associated with memory, emotion, immune function, hormone function, and basic drives. Now you know why scents are so closely linked to emotions and memories.

Aromas can alter heart rate, blood pressure, and breath rate, and some have the ability to stimulate the release of enkephalin, a compound your body uses to stop pain and improve mood. Some aromas prompt the release of the chemical norepinephrine, which then stimulates the immune system and reduces feelings of fatigue. Still others stimulate the raphe nucleus, which is found in the brain stem, to release serotonin, producing a sedative action that helps lower blood pressure while relieving issues like insomnia and anxiety. Clearly, when you use aromatherapy, your body’s chemistry changes for the better, and that can greatly improve your health overall.

Clary sage essential oil can even take on tough bacteria. A study conducted in 2015 proved its ability to kill three strains of Staphylococcus, according to researchers at the Medical University of Lodz in Poland.