How to Use Essential Oils

By Kristie Reilly and Temma Ehrenfeld @temmaehrenfeld
August 31, 2023
How to Use Essential Oils

Discover the science behind aromatherapy and other uses of oils distilled from plants. Is there an essential oil that could help you? Here’s what you should know and do.

Essential oils have been used for thousands of years, dating back at least to the Egyptians. They can be made from virtually any plant. Common methods for obtaining the essence of a plant include steam distillation and expelling (orange rinds can be crushed to release their oil, for example) for aromatherapy and medical uses.  

However essential oils are extracted, they tend to be expensive because so much of a plant is required — as much as a room's worth to produce even a tiny bottle. 


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What are the risks of essential oils?

Many common medicines come from plants. Healers used willow bark as a pain and fever remedy for centuries before scientists discovered that it contains the chemical salicin, which chemists later modified to make aspirin. The powerful painkillers codeine and morphine come from poppy plants. Modern opioids are synthetic versions of the same compounds.  

But be clear: When you purchase an essential from a store, you are trusting a manufacturer and do not benefit from the safeguards built into modern medicine.  In the United States, the Food and Drug Administration (FDA) requires pharmaceuticals to pass rigorous testing.  An essential oil, on the other hand, can be sold if it meets safety requirements for cosmetics.

As the FDA notes, the fact that a product is labeled “natural” or “organic” or comes from a plant doesn’t make it safe. Many plants contain materials that are toxic, irritating, or likely to cause allergic reactions when you apply them to your skin.

The agency regulates labeling, so the packaging won’t make any medical claims. But the bottle may not contain exactly what the label says. The same is true of vitamins and other supplements.

The reality is that you don’t have control over dosages. The plant substances in essential oils can vary depending on a plant’s growing conditions, and one batch may be different from another. You are also not taking a drug, which contains a particular plant ingredient that may help you. Plants have many compounds, which may or may not benefit you.

Scientific studies on essential oils

Researchers are becoming increasingly interested in studying the effects of plant products rather than isolating key ingredients that could produce a drug.  

In a review of a decade of research, a Thai team found 70 studies that reported the effects of essential oils on the nervous system. Lavender was studied the most, followed by citrus scents. In nearly 60 percent of the studies, the essential oil was inhaled.

People don’t ordinarily inhale drugs. But if you’ve ever relaxed to the smell of baking cookies, you might be drawn to aromatherapy, which tries to change your mood through a scent.

One study the Thai scientists reviewed tested how inhaling a grapefruit essential oil affected several healthy young men. After measuring blood pressure, muscle activity, and cortisol levels, the researchers found evidence of changes that study volunteers reported to be pleasant and relaxing. Their levels of cortisol, the stress hormone, dropped after 10 minutes.

Another study they reviewed tested the effect of bergamot on postpartum depression. A small group of patients in a postpartum care center in Taiwan were randomly chosen to receive 15 minutes of smelling bergamot essential oil daily during their stay.  A control group was treated with steam from only water. A month after the treatment, the women treated with bergamot had significantly better results on a standard measure of depression.

The Thai scientists reported that “lavender, chamomile, bergamot, sweet orange, anise, geranium, and mountain pepper reduced depression in the elderly, postpartum women, restless patients, breast cancer patients, irritable bowel syndrome patients, mixed anxiety and depressive disorder, and residents in a long-term care unit.” Lavender, bergamot and lemon balm, they report, relieved pain in animals and a few human studies.

The authors suggest a wide variety of benefits: “Essential oils could alleviate fatigue, memory problems, behavioral symptoms, stress, inhalant cravings, and sleep problems without the potential for abuse.”

Essential oils as a germ-killer

The mouthwash Listerine is made with menthol (from mint), thymol (from thyme), methyl salicylate (from wintergreen), and eucalyptol (from, of course, eucalyptus). A review sponsored by its manufacturer, Johnson & Johnson, found the mouthwash is effective at controlling plaque and gingivitis and won acceptance from the Journal of the American Dental Association.

Gingivitis is a bacterial infection. Plants need to protect themselves against harmful microbes and produce many compounds to do so. While current antibiotics originate mostly from bacteria or fungi, herbal approaches may be the next frontier as alternatives or supplements to antibiotics. As more microbes develop resistance to antibiotics, it’s important to find other options.

According to one overview, about a dozen oils have useful properties. Lavender oil, for example, is active against one drug-resistant strain of E. coli and the drug-resistant “superbug” staph MRSA. Thyme, peppermint, cinnamon, clove, eucalyptus, sage, and tea tree all have promising effects. Their action is “significantly weaker compared to synthetic compounds, including antibiotics,” the authors note.

But researchers have become interested in approaches combining plant compounds with current drugs. The search is on to find good delivery methods and combinations.

How to use essential oils

While research is ongoing, be very careful if you'd like to try essential oils. Read customer reviews and start slowly.

Dilute any oil in water or oil you apply to your skin. Check instructions on the bottle; no more than a few drops (five to 10) for every 2 ounces is usually sufficient. Any more, and you risk skin irritation or more serious complications.

In the absence of further research, it's best to avoid ingesting essential oils altogether. Some have been shown to lead to liver damage, among other harmful effects.

Be especially cautious with children and animals, since oils can have bigger effects on their smaller bodies. One veterinary journal reported a case of three cats bathed in 100 percent tea tree oil. One died, and the other two suffered severe complications.

If you'd like to use essential oils with pets or kids, aromatherapy may be safest. Simply place a few drops in a diffuser around your house. 


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August 31, 2023

Reviewed By:  

Janet O’Dell, RN