Essential Oils for Cancer: Research, Benefits & Safe Uses

QUICK SUMMARY

Essential oils for cancer are being studied for their effects on cancer cells in laboratory and animal research, but no essential oil has been clinically established as a treatment or cure for cancer in people. In integrative oncology, carefully selected aromatherapy may help some patients with symptoms such as anxiety, nausea, or distress alongside appropriate medical treatment. Frankincense, citrus, clary sage, lavender, lemongrass, myrrh, peppermint, spearmint, and thyme are among the oils discussed in this research guide.

Of all the popular natural solutions out there, essential oils for cancer have gained significant attention and become controversial because of claims shared online. This article unpacks fact from fiction, explores the research, and offers practical ways to approach essential oils during cancer care with discernment.

Cancer touches families deeply. We believe there is room for both hope and careful investigation, without making promises that the science has not established.

Three Important Considerations

The truth about essential oils for cancer is three-fold.

First – much of the research into direct anticancer activity comes from in vitro experiments and animal studies. Those findings are worth studying, but they cannot establish that essential oils prevent or treat cancer in people. Human aromatherapy research has focused primarily on supportive care, with mixed results depending on the symptom, oil, and study design. Claims about essential oils treating cancer itself remain experimental.

Second – it is critical to recognize that this is not an all-or-nothing approach. Just because you’re taking chemo doesn’t mean that you can’t use essential oils for cancer. The same is true on the flip side of that coin. Far too many patients and healthcare practitioners dichotomize natural from allopathic therapies and do not give enough emphasis on the practicality of using both together. This field of study is called “integrative oncology” and is growing rapidly.

Third – personal testimonies of healing deserve compassion and respectful listening. We thank God for every recovery. But stories alone cannot show whether an essential oil caused remission, especially when someone also received medical treatment or experienced other changes. Testimonies can inspire questions for future research, not replace controlled clinical evidence.

Best Essential Oils for Cancer

Of all of the studies in the medical literature, this is just a sample of those that suggest essential oils for cancer treatment or therapy can benefit patients.

1. Citrus Oils

The most prominent and noteworthy component of most citrus essential oils is d-limonene, being investigated for possible anticancer activity. In the words of the U.S. National Library of Medicine’s open chemistry database, PubChem, (32)

“D-Limonene is an oral dietary supplement containing a natural cyclic monoterpene and major component of the oil extracted from citrus peels with potential chemopreventive and antitumor activities. Although the mechanism of action has yet to be fully elucidated, limonene and its metabolites perillic acid, dihydroperillic acid, uroterpenol and limonene 1,2-diol may inhibit tumor growth through inhibition of p21-dependent signaling and may induce apoptosis via the induction of the transforming growth factor beta-signaling pathway. In addition, they inhibit post-translational modification of signal transduction proteins, resulting in G1 cell cycle arrest as well as differential expression of cell cycle- and apoptosis-related genes.”

2. Clary Sage

Sclareol, a constituent of clary sage essential oil, has promising anticancer effects in laboratory evaluations. Studies dating between 1999 to just last year have been shown to impact the way that cancer cells proliferate by literally killing through a process known as apoptosis. (1, 2)

Apoptosis is interesting because it literally triggers the cell to commit “suicide,” more formally known as programmed cell death, but this does not show that clary sage essential oil prevents or treats cancer in people.

Sclareol has shown some promising things in lab tests. Over the last couple of decades but as recently as this year (2015), studies have emerged that analyze sclareol’s effect on cancer cells. With the caveat that these benefits occurred within the confines of lab cultures and dose adjustments, sclareol may have an impact on the way that cancer cells proliferate, and they could help to induce apoptosis (cancer cell death).

While this does not tell us how much potential sclareol has to directly treat cancer – and it’s exciting to think about where that could go one day! – it is a common thread that we see in many antioxidant-rich essential oils. This is especially interesting for clary sage because some claim that it is “estrogenic” due to the sclareol content and should be avoided by estrogen-dominant cancer patients.

This is an incorrect assumption, according to essential oil safety expert Robert Tisserand puts it this way:

“Sclareol does have an interesting anticancer activity, including in vitro action against human breast cancer MCF-7 cells (Dimas et al. 2006). An isomer, 13-epi-sclareol, which is also present in clary sage oil, inhibits the growth of breast and uterine cancers in vitro, and was slightly more potent than Tamoxifen, but was not toxic to normal cells (Sashidhara et al 2007). This suggests the possibility that sclareol might actually inhibit estrogen, and might after all have some capacity to interact with estrogen receptor sites. What we do know is that sclareol will not give you breast cancer.” (3)

3. Frankincense

Of all the cancer-fighting essential oils, frankincense essential oil (Boswellia sacra, B. carterii, B. frereana, and B. serrata) is the most controversial. The research out there has been scrutinized because of its industry bias, and some claim that there are no chemical compounds in frankincense oil that can kill cancer. With that said, healing stories can be found online. Those experiences matter to the people sharing them, but they do not establish that frankincense cured their cancer.

The biggest issue some chemists and Aromatherapists have is regarding boswellic acids (BAs), which have been described as “cytotoxic to ovarian cancer cells at pharmacologically achievable concentrations” in laboratory research and “may form the basis of a novel anticancer treatment for ovarian cancer, perhaps alongside conventional chemotherapy.” (4) A known compound in frankincense resin, the issue is that boswellic acids are too large and heavy to be included in the volatile (evaporated) components that make up essential oils.

In other words, BA’s are not in the essential oils. Nonetheless, in vitro studies continue to emerge demonstrating the anticancer effects of frankincense essential oil on the bladder (5), breast (6), and skin (7) cancers.

Other research has evaluated Boswellia serrata extracts for cerebral edema (brain swelling) during radiation treatment. These extracts are not interchangeable with frankincense essential oil. A clinical trial published in 2011 evaluated 44 patients with cerebral edema and, after taking 4200 mg/day of a Boswellia serrata (BS) extract was administered, the swelling was reduced by 75% or more in 60% of the participants. The researchers conclude that “BS could potentially be steroid-sparing for patients receiving brain irradiation. (8)

Frankincense is also being investigated for effects on inflammation and well-being, but clinical evidence is not sufficient to promise relief from depression, pain, or immune suppression in people with cancer. (9, 10)

4. Lavender

A popular theme in the natural health discussion is that antioxidants are the superhealers that we all need. Free radicals created by chemicals, pollutants, stress, and toxins are the culprits for a cascade of cellular damage, immune inhibition, and limitless unforeseen health risks – including cancer and chronic illness.

Suffice it to say that, if free radicals are the supervillains, antioxidants are the superheroes.

The body itself creates antioxidants in the form of the enzymes catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) among others. Unfortunately, our bodies are exposed to a constant onslaught of free radicals that drain our naturally occurring antioxidants but that does not mean everyone needs antioxidant supplements.

Lavender essential oil has shown antioxidant-related effects in preclinical research, although this is not evidence that it prevents cancer in people.

Of the major antioxidant enzymes mentioned above, Chinese researchers observed that lavender essential oil can upregulate levels of all three in mice within the first day of treatment and protect brain cells against stroke and injury! (11) Romanian researchers noted similar activity by simply inhaling lavender for an hour each day. According to the study, “Taken together, our results suggest that antioxidant and antiapoptotic activities [of healthy brain cells] of the lavender essential oils are the major mechanisms for their potent neuroprotective effects against scopolamine-induced oxidative stress in the rat brain,” in this experimental model, not cancer outcomes in humans. (12)

5. Lemongrass

Several studies have evaluated the potential properties of lemongrass essential oil as part of a natural cancer treatment support. (13)

In 2009, an article was published that evaluated the essential oil of Cymbopogon flexuosus (a variety of lemongrass) for its in vitro cytotoxicity ability against 12 human cancer cell lines; as well as its anticancer effects on mice in vivo. The findings were promising for further study. Researchers observed mechanisms associated with cancer-cell death in these experimental models. “Our results indicate that the oil has a promising anticancer activity and causes loss in tumor cell viability by activating the apoptotic process as identified by electron microscopy.” (14)

6. Myrrh

The role that myrrh essential oil plays in natural cancer therapies is becoming a popular topic in the scientific community. Particularly, with how it interacts with frankincense essential oils. In 2013, one of the most thorough studies on the topic was published in the journal Oncology Letters, and this is what the researcher discovered:

“The effects of the two essential oils, independently and as a mixture, on five tumor cell lines, MCF-7, HS-1, HepG2, HeLa, and A549, were investigated using the MTT assay. The results indicated that the MCF-7 and HS-1 cell lines showed increased sensitivity to the myrrh and frankincense essential oils compared with the remaining cell lines. In addition, the anticancer effects of myrrh were markedly increased compared with those of frankincense, however, no significant synergistic effects were identified.” (15)

Don’t think that researchers are evaluating frankincense and myrrh together as complementary therapies because of the Christmas story. Oh, no. The resins from frankincense and myrrh trees have been traditionally prescribed simultaneously in Chinese medicine for years. Used primarily to treat inflammatory diseases, and blood stagnation, the resins have a long history of use for swelling and pain, although traditional use does not prove effectiveness for cancer. Even though researchers have not observed a synergistic effect regarding cancer, “A previous study identified that the combination of frankincense and myrrh oils exhibited synergistic effects on harmful bacterial infections Cryptococcus neoformans and Pseudomonas aeruginosa.” (14, 16)

7. Peppermint & Spearmint

In 2014, the journal BioMed Research International published an article uncovering that peppermint essential oil and spearmint discussed the potential of essential oils for managing symptoms associated with cancer treatment, including nausea and vomiting. Individual studies are small, and results should not be treated as guaranteed. Taken directly from the study we find that these oils, as well as some others, can help with a variety of conditions cancer patients suffer from:

• “Cancer patients suffer from different side effects which can be preferentially reduced by alternative methods. EOs are used in aromatherapy to reduce the agony of brain cancer patients (17). EO is efficient in depression and reduction of anxiety in cancer patients (18). Cancer patients undergoing chemotherapy, one of the most frequently used treatment methods for cancer, are prone to various side effects (19). These are nausea and vomiting.
• Mentha spicata [spearmint] and M. piperita [peppermint] are effective in overcoming these emetic conditions (chemotherapy-induced nausea and vomiting, CINV) along with the reduction of expenditure on treatment in cancer patients undergoing chemotherapy (20).
• EOs of Leptospermum scoparium [Manuka myrtle] and Kunzea ericoides [Karo Greenfingers] were reported to prevent mucositis in the head and neck cancer patients undergoing radiotherapy when used in the preparation of mouthwash (21).
• Some cancer patients having metastatic tumorigenic ulcers of the skin develop necrosis and malodor (22). Patients suffering from such malodor were reported to have an improvement in their state on the treatment of these ulcers with the mixture of eucalyptus, melaleuca, lemongrass, lemon, clove leaf, and thyme essential oils on a 40% ethanol base (23).
• Lavender essential oil is widely used in aromatherapy and is found to be beneficial in reducing distress in cancer patients (24). Hence, EOs serve as the valuable preparations in amelioration of the side effects and sufferings of the cancer patients.”

8. Thyme

The journal Molecules published a study in 2010 that evaluated how cancer cells could stand up against ten powerful essential oils. Included was thyme, which showed activity against prostate, lung, and breast cancer cell lines in laboratory testing. (25)

Laboratory findings about estrogen-related pathways should not be interpreted to mean thyme essential oil balances or regulates hormones in people. (26) As we noted above with clary sage, thyme is not the only potential estrogenic essential oil noted for its anticancer potential. It should be interesting to note that, because cancer frequently holds receptors for estrogen and can theoretically be “fed” by any compound that is estrogenic, people at risk of developing certain cancer lines are oftentimes advised to avoid estrogen.

These findings give researchers worthwhile questions to pursue. They do not establish that essential oils are safe for every hormone-sensitive cancer or that any oil can replace an evidence-based treatment.

Common Side Effects of Cancer Treatment Protocols

It’s common knowledge that cancer treatments cause a slew of side effects – problems that people suffer when medical treatment damages healthy tissues or organs.

The National Cancer Institute recommends that you, “Ask your health care team what side effects you are likely to have” and to get information about ways to prevent or manage specific cancer-related side effects is included in the list below.” (27)

Cancer symptom management can be complicated, and even helpful treatments may have side effects. That is one reason we encourage conversations with the oncology team about supportive care, including approaches that do not add unnecessary burdens.

Case in point: our good friend recently developed colitis during immunotherapy. Immunotherapy can cause immune-mediated colitis; it should not automatically be attributed to destruction of gut flora. According to the National Cancer Institute, other common complications to cancer treatments include: (27)

• Anemia
• Appetite Loss
• Bleeding and Bruising (Thrombocytopenia)
• Constipation
• Delirium
• Diarrhea
• Edema
• Fatigue
• Fertility Issues in Boys and Men
• Fertility Issues in Girls and Women
• Hair Loss (Alopecia)
• Infection and Neutropenia
• Lymphedema
• Memory or Concentration Problems
• Mouth and Throat Problems
• Nausea and Vomiting
• Nerve Problems (Peripheral Neuropathy)
• Pain
• Sexual Health Issues in Men
• Sexual Health Issues in Women
• Skin and Nail Changes
• Sleep Problems
• Urinary and Bladder Problems

So, what’s a person to do?

Using Essential Oils with Conventional Medicine

It’s important to realize that natural therapies can and, in many situations, should be used in conjunction with conventional medicine (unless obvious contraindications are present and your oncologist recommends against it). It’s not an all-or-nothing thing. Meaning, people oftentimes feel that they only have two options:

1. Either go the “all-natural” route
2. Or follow the allopathic model.

But this is NOT the case.

Many do not realize that supportive integrative care may improve comfort and quality of life while conventional cancer treatment addresses the disease. In the words of a 2014 article in the journal BioMed Research International, (28)

“EOs have also been reported to improve the quality of life of the cancer patients by lowering the level of their agony (29). EOs-mediated therapy cannot be a substitute to the standard chemotherapy and radiotherapy but can be used in combination with cancer therapy to decrease the side effects of the drugs. Hence, EOs can be used for improving the health of the cancer patients and as a source of novel anticancer compounds….Use of the EOs as dietary supplements and coadministration with drugs can enhance the response to the treatment.”

The review raises interesting possibilities, but its suggestion about supplements and drug responses is not proof of safe or effective combinations. Work with an oncologist who is willing to discuss integrative care, medication interactions, and a plan tailored to you.

Practical Suggestions & Uses

For cancer care, consider three distinct routes: inhalation, diluted topical application, and internal use. The route matters. Never assume that an oil appropriate for diffusion or massage is appropriate to consume. Culinary use in food is different from medicinal internal use, which requires oil-specific guidance and an oncology-team review for interactions. Avoid applying oils to radiation-treated skin, damaged skin, or treatment-device sites unless your care team approves.

When diffusing, follow the instructions on your diffuser. Generally, 4-5 drops (in total) are recommended.

When applying topically, be sure to dilute with a carrier oil using these conversions:

• 1% dilution: 6 drops of EO per oz of carrier oil
• 2% dilution: 12 drops of EO per oz of carrier oil
• 3% dilution: 18 drops of EO per oz of carrier oil
• 5% dilution: 30 drops of EO per oz of carrier

If working with tablespoons is more comfortable for you, 1 oz. = 2 tablespoons.

• 1% dilution: 3 drops of EO per tablespoon of carrier oil
• 2% dilution: 6 drops of EO per tablespoon of carrier oil
• 3% dilution: 9 drops of EO per tablespoon of carrier oil
• 5% dilution: 15 drops of EO per tablespoon of carrier

Download our free essential oil dilution guide to reference as needed. 

To make an Immunity / Cellular Rejuvenation Blend, start off by mixing equal parts of 2-3 of the oils below unless otherwise noted. There is no “magic formula.” You’ll need to find something that works for you.

• Basil*
• Black Pepper
• Cardamom
• Cinnamon*
• Clary Sage
• Clove*
• Fennel*
• Frankincense
• Helichrysum
• Lemongrass*
• Melissa*
• Myrrh
• Orange
• Oregano*
• Peppermint
• Rosemary
• Sandalwood
• Tea Tree
• Thyme*

*Use caution with these essential oils to avoid the maximum dermal limits in your dilutions. You’ll want to mix them at a much lower percentage. The dilution figures above are general conversion references, not recommended concentrations for every oil or for skin affected by cancer treatment. Begin conservatively and consult with Tisserand & Young’s Essential Oil Safety textbook.

To make a Joyful Blend, start off by mixing equal parts of 2-3 of the oils below.

• Citrus Oils (bergamot, clementine, grapefruit, lemon, lime, neroli, sweet orange, tangerine, yuzu, etc.)
• Frankincense
• Lemon Myrtle
• Melissa
• Sandalwood
• Vanilla
• Ylang ylang

To make a Digestion Blend, start off by mixing equal parts of 2-3 of the oils below.

• Anise
• Carraway
• Fennel
• Ginger
• Lemon
• Peppermint
• Rosemary
• Tarragon

To make a Respiratory Support Blend, start off by mixing equal parts of 2-3 of the oils below.

• Cardamom
• Eucalyptus
• Lemon
• Peppermint
• Rosemary
• Tea Tree

To make a Muscle Soothing Blend, start off by mixing equal parts of 2-3 of the oils below.

• Balsam/White Fir
• Birch
• Chamomile
• Clary Sage
• Copaiba
• Cypress
• Frankincense
• Helichrysum
• Juniper
• Lemongrass
• Marjoram
• Osmanthus
• Peppermint
• Rosemary
• Yarrow
• Wintergreen

Parting Words About Cancer Treatment

Let’s remember that peer-reviewed articles about essential oils and cancer describe intriguing effects on cancer cells in laboratory experiments and some animal models. Those results cannot simply be extrapolated to people living with cancer. We can take this research seriously without claiming that an essential oil has been proven to prevent, stop, or reverse cancer in a patient.

As we discuss in The Essential Oils Apothecary, cancer support is about caring for the whole person. Essential oils may have a thoughtful place in comfort-focused integrative care, alongside appropriate oncology treatment, nourishing habits, emotional support, and prayer. Our hope is that ongoing research brings greater clarity while families make informed, compassionate decisions today.

Additional Essential Oils for Cancer References

• Composite Essential Oils and Cancer Studies
• Cinnamon Oil and Cancer Studies
• Clove Oil and Cancer Studies
• Frankincense Oil and Cancer Studies
• Lemongrass Oil and Cancer Studies
• Melissa Oil and Cancer Studies
• Sandalwood Oil and Cancer Studies
• Thyme Oil and Cancer Studies

Essential Oils for Breast Cancer-Specific Research

• Black Pepper, Cinnamon, Clove, Oregano and Breast Cancer
• Cardamom and Breast Cancer
• Fennel and Breast Cancer
• Clary Sage and Breast Cancer
• Frankincense and Breast Cancer
• Melaleuca and Breast Cancer
• Helichrysum and Breast Cancer
• Oregano and Breast Cancer (Study 1)
• Oregano and Breast Cancer (Study 2)
• Peppermint and Breast Cancer
• Rosemary and Breast Cancer
• Thyme and Breast Cancer

References: