One complementary therapy that has become increasingly popular is essential oils. Most of the research on oils points to their role as a supportive therapy in cancer care for symptoms such as nausea, vomiting, pain, and insomnia, per a 2018 paper. Sometimes, particularly in hospitals specifically focused on cancer care, experts in integrative medicine, such as aromatherapists, will be available to help you select the oils that you might want to try. If not, you can consult an aromatherapist on your own to help you understand how different oils should be used, notes Cancer Research UK. While essential oils may offer some benefits for people with cancer, there are many factors to consider before giving them a try. RELATED: 8 Complementary Therapies to Add to Your Chemo Treatment

What Are Essential Oils — and Which Are Most Commonly Used?

Essential oils are concentrated extracts of flowers, roots, leaves, stems, seeds, resin, bark, or fruit rinds. There are more than 400 essential oils available, and they can be purchased at most health food stores. The oils are thought to work by absorbing into your body’s tissues via topical application, inhalation, or, in some cases, consumption. Some of the most popular essential oils used for supportive care in cancer include:

RosemaryLavenderChamomileEucalyptusPeppermintJasmineLemonMarjoramYlang ylangGeraniumGingerFrankincense

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Can Essential Oils Treat Cancer?

To date, there are no scientific studies showing that aromatherapy can cure or prevent cancer. Most of the research showing promising results has been done in vitro, meaning that the essential oil was found to affect cancer cells in a petri dish. For example, results of a 2015 study suggested that breast cancer cells may stop growing and die off when exposed to frankincense oil. In a 2018 paper, scientists looked at the role of essential oils in various laboratory studies. The authors in this review concluded that “although this is a relatively new and emerging area of cancer research, the ability of essential oils and their components of having such diverse anti-cancer effects through acting on various and cellular mechanisms is compelling.” While these limited studies may offer encouraging data, it’s important to note that findings in the lab don’t necessarily translate to benefits for humans. “Some essential oils may have anti-cancer effects as per laboratory studies on cancer cells, but I haven’t seen any studies looking at the anti-cancer effects of essential oils in humans,” says David Kiefer, MD, medical director for the Integrative Health Consult Clinic at the University of Wisconsin in Madison. RELATED: 5 Ways to Boost Your Quality of Life During Prostate Cancer Treatment

Research on Oils for Supportive Care

Most of the human studies on essential oils for cancer focus on helping improve quality of life, anxiety, symptoms, and side effects of treatment. “There is some research for aromatherapy being beneficial for nausea, vomiting, and insomnia,” Dr. Kiefer says. “Other studies have looked at using essential oil mixtures on the skin to treat skin reactions that may occur from cancer treatments.” In a 1999 randomized controlled trial, researchers compared the effects of standard massage and aromatherapy massage in 103 cancer patients. Those who received the aromatherapy massage with a Roman chamomile essential oil reported a statistically significant reduction in anxiety and an improvement in symptoms. In contrast, the massage-only group showed some improvements, but they weren’t statistically significant, according to the National Cancer Institute. A 2015 study, examined the effects of inhaled ginger essential oil in women with breast cancer who experienced chemo-induced nausea and vomiting. Results showed that aromatherapy did not result in a statistically significant reduction in nausea and vomiting. In a 1998 trial, cancer patients who completed six aromatherapy sessions reported significant improvements in anxiety and depression. Still, other studies have shown no benefits of aromatherapy. More research is needed to determine just how effective this approach is for helping people with cancer cope with the symptoms they experience.

Are Essential Oils Safe?

Essential oils are generally safe for use if you have cancer, but they can pose side effects. “For example, young children can develop breathing problems with aromatherapy with some essential oils,” Kiefer says. “Aromatherapy can make some people’s breathing worse, such as if you have asthma.” Other possible side effects include:

A skin reaction or allergic reactionIncreased sun sensitivity (if applied before going in the sun)An unpleasant smell

Check with an herbal expert or healthcare provider before using any essential oil, especially if you’re pregnant, breastfeeding, or have another health issue. “Some people with certain medical conditions and ages, such as young children, shouldn’t use essential oils at all, which is why it’s important to check with someone about it first before using,” says Kiefer.

How Do You Use Essential Oils for Cancer?

Essential oils are highly concentrated, so you should always dilute them before rubbing them on your skin. Oils are often diluted with a “carrier” oil, which is an oil processed from seeds, nuts, or trees that can help spread the essential oil over a larger area of the skin, according to BreastCancer.org. Before applying an essential oil to your skin, perform a test on a small area and wait 24 hours to make sure you don’t have a reaction. If the skin becomes red or swollen, don’t use the oil again. Some other ways to use aromatherapy include:

Place a few drops of essential oil in an oil burner or diffuser.Put 10 to 15 drops of oil in a 4-ounce spray bottle of water. Shake it and spray it around the room.Put 5 to 10 drops of essential oil in your bath, using a bath gel or salt (since oil and water don’t mix).Sprinkle 2 to 4 drops of essential oil onto a handkerchief or cloth and hold it to your nose. Take two to three deep breaths through your nose while closing your eyes to avoid irritation.

It’s important to know that some essential oils are toxic when ingested and should not be tasted or placed near your mouth.

The Bottom Line on Essential Oils for Cancer

Ultimately, more research needs to be done to find out if essential oils are a legitimate treatment option for cancer and its symptoms. Generally, the oils pose few risks when used properly. They’re also a relatively simple and inexpensive way to complement your treatment. “As aromatherapy, they are possibly useful for some people who have nausea, vomiting, or insomnia; or topically for skin problems from some types of cancer treatment, but probably don’t have much of a role beyond that,” Kiefer concludes. “People should continue their standard care and never replace that care with essential oils.”