Essential oils are everywhere. These potent, fragrant plant extracts have made their way into lotions, household cleaners, massage treatments, and even integrative complementary therapy to help manage cancer symptoms.
Their purported benefits are also wide ranging, from improving sleep and decreasing anxiety, to lowering pain and easing headaches, to taming a queasy stomach and fostering deeper relaxation.
Here, we explain what essential oils are, how they work, their potential health benefits, safety considerations, and how to find quality oils.
History of Essential Oils
According to the Encyclopedia Britannica, the earliest records suggest that essential oils come from ancient India, Persia, and Egypt.
However, they’ve been used for centuries by many cultures for various purposes.
Ancient Egyptians used aromatic oils in cosmetics and ointments as early as 4500 B.C., whereas traditional Chinese and Indian medicine relied on aromatic oils for healing between 3000 and 2000 B.C.
Similarly, aromatherapy, or the practice of using aromatic materials, including essential oils, for physiological and physical wellness, has been used for centuries.
The oils were called “essential” because they were thought to represent the essence of odor and flavor coming from the plant sources they were derived from.
In the Western world, French chemist René-Maurice Gattefossé is credited with founding the science of aromatherapy in 1928, drawing upon its ancient, global roots. He began analyzing the chemical properties of essential oils after witnessing the healing properties of lavender oil when applied to a burn on his hand. However, aromatherapy didn’t gain popularity in the United States until the 1980s.
How Essential Oils Are Derived and How They Work
Essential oils are made by steaming or pressing various parts of a plant to capture the compounds that give the plant its unique fragrance. Those oils can then be inhaled, added to a carrier oil for direct application on the skin, consumed orally (some, not all), or used in household products to clean and sanitize.
When inhaled, the molecules in essential oils travel up the nose and interact with scent receptors, which stimulates the olfactory nerve that connects to the brain.
“The oil itself doesn’t go up into the brain, but it stimulates a response that typically affects different aspects of the brain and the central nervous system, specifically in regions called the limbic system. This system has a lot to do with arousal, memory, and processing emotions,” says Michelle Davila, ND, a naturopathic doctor with the integrative medicine department of Beaumont Health in Grosse Pointe and Royal Oak, Michigan.
For example, scientists believe lavender stimulates the brain similarly to some sedative medications, according to the Icahn School of Medicine at Mount Sinai in New York City.
However, one review, which evaluated several studies on the efficacy of lavender therapy in neurological disorders, found that longer-term follow-ups, larger studies, and more consistent clinical parameters are needed before its usage should be recommended for treatment of nervous system or psychological concerns.
Essential oils also create certain effects when applied to the skin. “Because of their low molecular weight and the fact that they’re fat-soluble, essential oils can get into the bloodstream and affect different aspects of our overall health,” Dr. Davila explains.
“But whether you use aromatherapy through the olfactory nerve [or the lungs], or through absorption [via] the skin, the effects are fairly similar,” she adds.
Many people use essential oils on their own at home. However, they’re also used by a variety of healthcare professionals and in various settings with patients. According to the National Center for Complementary and Integrative Health (NCCIH), aromatherapy is sometimes incorporated into massage therapy for knee pain from osteoarthritis or pain, anxiety, and other symptoms in people with cancer.
They’re also used by doctors, nurses, chiropractors, acupuncturists, holistic healthcare providers, and dentists, notes Shanti Dechen, a certified clinical aromatherapy practitioner and licensed massage therapist, who is director of Aroma Apothecary Healing Arts Academy in Crestone, Colorado.
Unfortunately, both the practice of aromatherapy and the manufacture of aromatherapy products like essential oils are currently unregulated in the United States.
Additionally, aromatherapists aren’t required to be licensed or certified.
However, many organizations offer education and certification programs. The National Association for Holistic Aromatherapy (NAHA) is an educational nonprofit organization that has created guidelines for aromatherapy certification programs. Check that your aromatherapist has received training from a NAHA-approved aromatherapy school.
Ways to Breathe In Essential Oils
One of the most common ways people work with essential oils is by inhaling them via diffuser, dry evaporation, aroma sticks, or steam.
This is a device that breaks essential oils down into smaller molecules and sends them into the surrounding air. Some devices use water and heat so the oils evaporate.
Also known as an essential oil inhaler, an aroma stick is a portable plastic device with an absorbent wick at one end. The wick soaks up the essential oil and the accompanying cover protects the scent until you’re ready to remove it for a sniff. You can carry an aroma stick with you for inhales of aromatherapy throughout the day.
Dry evaporation is exactly what it sounds like: Using a dry material to release the scent of an essential oil. Simply place several drops of essential oil on a cotton ball or tissue, or other absorbent material, like terra cotta, and allow it to evaporate into the air. You can sniff the cotton ball or keep it nearby.
Essential Oil Application to the Skin
Another common method of using essential oils is to apply them directly to the skin through a massage, bath, or skincare product. However, it’s important to note that most essential oils should not be applied directly to the skin without being diluted first.
Typically, topical essential oils are mixed with a carrier oil like jojoba, castor, or avocado oil to aid absorption, provide additional vitamins, and safeguard your skin against allergic reactions.
“Carrier oils make essential oils a lot safer, because what they’ve found over years of research is that if you apply an essential oil [that’s] undiluted, it will create allergic reactions in many people over time,” Dechen says.
Other common carrier oils include sweet almond oil, apricot kernel oil, or grapeseed oil.
The University of Minnesota’s Earl E. Bakken Center for Spirituality and Healing recommends diluting essential oils in a carrier oil at a concentration no greater than 1 percent when used in a massage oil. So, that would be 1 drop of pure essential for every 1 teaspoon of carrier oil.
Can I Eat or Vape Essential Oils?
Essential oils can also theoretically be ingested or vaped, but experts warn that these approaches can be very dangerous, and to steer clear.
“Ingesting essential oils in water or capsules is something that requires advanced knowledge and training to do,” Davila says. Typically, the drink or capsule has to be specially formulated and diluted to the proper degree. What’s more, you have to know how much to ingest and for how long, and which ones are safe. Ingesting essential oils the wrong way can irritate your esophagus and stomach, or worse, be toxic, Davila warns.
According to Dechen, drinking essential oils in a glass of that water will send the molecules right into the membranes of your mouth. “Over time, it [can] create scar tissue and irritation,” she says.
Vaping — inhaling and exhaling a vapor via a vape pen, similar to an e-cigarette device — is also a potentially dangerous approach to using essential oils. “Currently there’s no real research available on the effects of vaping essential oils,” Dechen says. And while essential oils are generally considered safe for inhalation, heating them with the metal coil inside the vape pen has the potential to change their chemistry and become toxic when inhaled into the mouth, throat, and lungs, she says. Bottom line, do not vape essential oils.
Possible Health Benefits of Essential Oils
Essential oils have the ability to affect the brain and travel throughout the body via the bloodstream. Here are a few of the potential benefits, when applied or inhaled safely:
Dechen says many people gravitate toward aromatherapy as a means of calming anxiety.
Research suggests there may be potential physiological benefits of aromatherapy in calming the nervous system. A recent review and meta-analysis of 90 studies (both randomized and nonrandomized) found that inhaling or ingesting lavender essential oil, diluted and under guidance, can significantly reduce anxiety levels. Incorporating lavender essential oil into massage was also found to help lower anxiety. However, authors say that studies on lavender and anxiety are of lower average quality. So, take these findings with a grain of salt.
Still, authors also say that, as inhaling lavender essential oil is generally safe, simple, and inexpensive, it may be considered as a therapeutic option for anxiety in some cases.
Lavender essential oil is thought to contain compounds that interact with the limbic system, the part of the brain that regulates your emotions. When inhaled, lavender exerts a relaxing effect, though much of the research has been done in test tubes and on animals.
Other essential oils that may lower anxiety include lemongrass oil, orange oil, bergamot oil, and cedarwood oil.
Promote and Aid Sleep
Given essential oils’ apparent relaxing effects, it’s unsurprising they may have the potential to help people sleep better.
In one small past study of 60 patients in a cardiac intensive care unit (ICU) in Turkey, those who inhaled lavender essential oil for 15 days saw significant improvements in sleep quality and decreased anxiety levels compared to patients who did not inhale the oil.
Another small past laboratory study had 31 healthy young adults, ages 18 to 30, stay in a sleep lab for three nights, and looked at the effects of sniffing lavender essential oil before bed versus a night without it (the control). Researchers discovered that lavender boosted slow- and deep-wave sleep and subjects also reported feeling “higher vigor” the next morning on their lavender smelling night compared to their control night.
Keep in mind that these studies were done in a short period of time, with small groups of people. Long-term studies using larger population sizes are needed to determine whether lavender can really assist with falling, and staying, asleep.
Essential oils like peppermint and ginger have unique characteristics that may make them ideal for soothing nausea.
Peppermint oil, for example, helps relax gastrointestinal (GI) muscles and lower inflammation that contributes to nausea, and is used as a medicine to help manage IBS and other functional GI disorders.
Meanwhile, ginger speeds up digestion, preventing foods from sitting in the digestive tract and causing discomfort.
In a recent small study of 100 hospitalized patients, those who inhaled peppermint essential oil saw significant reductions in nausea and vomiting. In fact, their improvements were comparable to patients who combined aromatherapy with an antiemetic (anti-nausea medication).
Essential Oils Safety and Side Effects
Just because essential oils come from plants doesn’t mean they’re totally safe.
“There are definitely safety concerns,” Davila says. “Essential oils are so concentrated that, sometimes, one drop of an essential oil is like an ounce or more of the plant material.”
Due to their potency, essential oils can cause irritation when applied to the skin — even if used with a carrier oil. While you can experience an allergic reaction to any essential oil, as each individual’s body chemistry differs from the next, some oils are more likely to cause discomfort. Those oils include:
- Oregano oil
- Cinnamon bark oil
- Jasmine oil
- Lemongrass oil
- Ylang-ylang oil
- Chamomile oil
- Bergamot oil
Take caution with applying essential oils if you have allergies or sensitive skin. (And remember to always dilute them with a carrier oil.)
In addition, some essential oils are photosensitive, meaning they react to ultraviolet light and create a reaction. When applied to skin, this reaction can make your skin more sensitive to sunlight, causing redness, discoloration, or even blistering.
These essential oils are known to interact with the skin when exposed to sunlight:
- Sweet orange
- Bitter orange
- Orange petitgrain
Davila recommends avoiding direct sunlight for 12 to 24 hours after using one of these oils on your skin.
Why Young Children Should Avoid Certain Essential Oils
While research on the effects of essential oils on children is thin, and the ethics of which is widely debated in the alternative and complementary healthcare community, two small studies have shown some oils may be potentially harmful to hormone production in youth. For example:
Many experts also warn against lavender and tea tree essential oils, as both have been found to contain chemicals that have physiological effects similar to estrogen.
What’s more, they inhibit the effects of androgen, the sex hormone that controls male characteristics. Past research suggests that the lavender and tea tree oil in personal care products may have been responsible for prepubertal gynecomastia (enlarged breast tissue in boys prior to puberty) in three young boys.
More recent case studies found similar effects in three prepubertal girls and one boy who used fragrances containing lavender essential oil.
While more research is needed to determine how lavender and tea tree oil may affect hormones, Davila recommends approaching both with caution. Avoid using them daily at high doses. Occasional use (once or twice a week) for short period of time (several weeks) may be fine, for adults.
Who Might Want to Try (and Avoid) Essential Oils
Essential oils show promise as a therapeutic modality for a wide range of health concerns, including anxiety, sleep issues, nausea, and pain.
That said, they’re not appropriate for everyone. Pregnant women, for example, should speak with a professional healthcare provider before using essential oils, as essential oils can cross the placental barrier.
“Typically, it’s recommended not to use them during the first trimester. If you use them in the second or third trimesters, limit yourself to the floral or citrus oils and use them for aromatherapy versus topical use,” Davila says.
And while essential oils aren’t off-limits for people with allergies and sensitive skin, these folks should approach them with caution when it comes to physical application, Davila warns.
Dechen doesn’t recommend using essential oils on infants or children younger than 5 years old, and being careful when using them with a chronic condition or medication. “There has been a lot of research over the last 10 to 15 years about how people taking medications can get reactions from different essential oils,” she says.
For example, past research suggests frankincense oil (Boswellia serrata) may interact with blood thinners like warfarin.
Check with your doctor before using essential oils if you take any medications.
Tips for Getting Started With Essential Oils
Before you get started with essential oils, you should determine your purpose for using them, as this will inform which oils you use. For example, if better sleep and stress relief are your wellness goals, you’ll want to opt for a calming essential oil like lavender, chamomile, basil, or frankincense. Meanwhile, stimulating oils like bergamot and peppermint oil may be better suited to people with depression or lower energy levels.
That said, choosing an essential oil is highly individual, so you may benefit from consulting a qualified aromatherapist.
What’s more, when and how often you use the essential oil may vary depending on your intended use. But no matter which essential oil(s) you choose, it’s important to use each with caution. Check that there are no contraindications for the essential oils you plan to use.
Once you’ve landed on the oils you want to try — and checked that there are no safety issues — head online or visit a holistic healthcare store. (Essential oils are available at aromatherapy shops, grocery stores, and supplement stores.)
The quality of essential oils vary widely, and there are a number of factors that affect it, including the plants used, processing methods, packaging and handling, and storage. Therefore, you should research to ensure the oils you choose are of quality, as advertised.
Here are a few things to look for when shopping for an essential oil:
- The Latin name of the plant
- The name of the country where the plants where grown
- A statement about the purity of the oil
You should also determine what application method you’d like to use. Inhalation via diffuser, steam, bath, aroma stick, or dry evaporation tends to be less irritating to the skin and works faster than topical applications.
Resources We Love on Essential Oils
- National Association for Holistic Aromatherapy (NAHA)
- Aroma Apothecary Healing Arts Academy
- Aromatherapy Registration Council
- International Council for Aromatic and Medicinal Plant (ICMAP)
- National Cancer Institute
- University of Minnesota Earl E. Bakken Center for Spirituality and Healing
- Aroma Web: Essential Oils Directory and Carrier Oils Properties and Profiles
- American Botanical Council
Original article: Everyday Health, May 31st, 2022