Maybe you have a favorite tea tree shampoo or lavender bubble bath that you use to relax. Scents from essential oils like these may make you feel happy and refreshed, and they are often valued parts of self-care rituals.

And during cancer, essential oils may be useful for some people in helping to relieve certain side effects of cancer and its treatment, such as anxiety and difficulty sleeping. Because of this, some people may wonder if the benefits of essential oils extend to helping treat or even prevent cancer. The simple answer is no. No studies have shown that essential oils can treat or prevent cancer in people.

However, their uses in relieving certain side effects are valuable to many people with cancer. Here, learn more about the benefits and risks of using essential oils during cancer, including the research behind their use in relieving side effects.

What are essential oils?

Essential oils are chemicals extracted from flowers, plants, or trees that are super concentrated in liquid form. You can inhale essential oils through a diffuser or massage them into your skin by combining them with other oils or lotions.

Common essential oils include:

  • Lavender

  • Tea tree

  • Ginger

  • Chamomile

  • Frankincense

  • Peppermint

  • Eucalyptus

Essential oils are most commonly used in aromatherapy, which is the practice of stimulating smell receptors in the nose by using these oils to help people feel better physically, emotionally, and spiritually. Aromatherapy has a long history, with its roots tracing back to ancient Rome and Egypt and, more recently, to 20th-century France.

Can essential oils prevent or treat cancer?

No studies have shown that essential oils can prevent or treat cancer in people. You may have seen articles saying that essential oils have “anti-cancer activity,” but these were likely studies of how cancer cells behaved in a petri dish or in mice with cancer. For example, frankincense oil stopped breast cancer cells from spreading in the laboratory in a 2015 study in the Asian Pacific Journal of Tropical Biomedicine. In a 2012 study in BMC Complementary Alternative Medicine, frankincense oil damaged pancreatic cancer cells in the laboratory and in pancreatic tumors in mice.

However, it’s important to remember that results from studies of cells in a laboratory or in experimental mice do not mean the product will be effective in preventing or treating cancer in humans.

Could essential oils help with my side effects from cancer and its treatment?

Cancer and its treatments can bring a wide range of physical and emotional side effects. Essential oils are considered a complementary therapy to standard medical treatments because they can help people with cancer manage side effects from the recommended cancer treatments and from the cancer itself. For this reason, you may consider trying complementary therapies such as aromatherapy to help ease your side effects. More specifically, aromatherapy may help with pain, sleep, anxiety, stress, quality of life, and possibly nausea and vomiting.

For example, a 2017 study in Oncology Nursing Forum of 50 people hospitalized for leukemia found that lavender, peppermint, or chamomile essential oils delivered by a diffuser at night improved sleep compared to a placebo. Meanwhile, in a small 2016 study of people receiving radioactive iodine treatment for thyroid cancer published in BioMed Research International, aromatherapy helped with a specific side effect: saliva production. Participants in the study inhaled either a ginger-lemon essential oil mixture or placebo (water) over 2 weeks. Those receiving the essential oils had better outcomes in terms of preventing damage to their salivary glands.

Some studies have also indicated that aromatherapy might help treat anxiety, but the evidence is limited. A 2003 study in the Journal of Clinical Oncology did not show any benefit, but a study of 103 people from a 1999 study in Palliative Medicine showed that adding essential oils to massage therapy seemed to improve the participants’ physical and psychological symptoms.

None of the studies mentioned above looked at home or personal use of aromatherapy, and research in this area is limited. However, many major cancer centers already offer aromatherapy as a form of supportive care.

The National Cancer Institute (NCI) has a detailed web page describing more studies where essential oils proved helpful in relieving several side effects of cancer and its treatment. NCI points out that many studies do not include good descriptions of the essential oils used, which makes it difficult to compare studies or to conduct larger analyses of the data. More rigorous, larger studies evaluating the effects of aromatherapy are needed.

Talking to your health care team is a good first step if you’re considering using essential oils, such as on your skin or in a diffuser. Discuss the side effects you’re experiencing with your health care team, and ask whether aromatherapy could be useful as a complementary therapy. Be sure to ask about your individual risks of using the specific aromatherapy you are interested in trying. And, watch for unwanted side effects from the essential oil product such as redness or irritation after you apply a skin lotion. Consider trying a small sample by smell or on your skin first to make sure you do not have a strong or unexpected reaction to the product.

What are the risks of using essential oils?

Some people are surprised to learn that, because even though such oils are derived from natural sources, these products can still cause irritation or allergic reactions, especially in people with sensitive or damaged skin. Some citrus essential oils, in particular, might react in the sun. Some people have experienced coughing or other respiratory problems with using a room diffuser. If a reaction or irritation occurs, stop using the product immediately. Never use undiluted essential oils on your skin, and keep essential oils away from your eyes.

Essential oils are not regulated by the U.S. Food and Drug Administration unless they make claims to prevent or cure disease, so it’s up to you—the consumer—to decide whether the product you are buying is reputable and trustworthy. You can buy essential oils that are Non-GMO Project Verified or U.S. Department of Agriculture (USDA) certified organic, meaning that the company uses certain quality practices in making the product.

How do I use essential oils?

Essential oils can be purchased at many chain stores, pharmacies, or smaller specialty shops online or in your local area. In many cases, you are buying the essential oil undiluted, to be used by adding it to a lotion or other oils like almond or coconut oil. You can also add essential oils to a room diffuser to create a steam mist. It’s important to note that essential oil products should generally not be ingested.