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Cancer and Complementary Health Approaches: What You Need To Know

A woman preparing and drinking some fresh hot tea in a travel mug. She is sitting on a small jetty on the lake in autumn.
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What’s the Bottom Line?

Complementary health approaches may play a role in cancer care, but using them inappropriately can be harmful. For your safety:

  • Don’t use unproven products or practices to replace or delay medical treatment for cancer.
  • If you have cancer, consult your health care provider before adding any complementary health products or practices to your treatment program.

What do we know about the usefulness of complementary approaches for cancer?

  • No complementary health approach has been shown to prevent or cure cancer.
  • Some complementary health approaches, such as acupuncture, mindfulness-based stress reduction, and yoga, may help manage cancer symptoms and side effects of treatment.

What do we know about the safety of complementary approaches for cancer?

  • Psychological and physical practices such as hypnosis, massage therapy, and yoga are usually safe when used appropriately. However, special precautions may need to be taken to make some of these practices safe for people with cancer.
  • Some complementary health approaches can interfere with medical treatment for cancer. For example, some herbs may make chemotherapy drugs less effective.
  • Some of the fraudulent cancer “cures” marketed via the internet are dangerous in themselves, and others can be harmful if people use them instead of seeking effective medical treatment.

About Cancer

Cancer is a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body. Although cancer is the second leading cause of death in the United States, people with cancer are living longer because of improvements in early detection and treatment. About two out of every three people in the United States diagnosed with cancer will live at least 5 years after diagnosis.

For more information about cancer, visit the National Cancer Institute (NCI) website.

About Complementary Health Approaches

Complementary health approaches are a group of diverse medical and health care systems, practices, and products whose origins come from outside of mainstream medicine. They include such products and practices as herbal supplements, other dietary supplements, meditation, spinal manipulation, and acupuncture.

Complementary approaches can be classified by their primary therapeutic input (how the therapy is taken in or delivered), which may be:

  • Nutritional (e.g., special diets, dietary supplements, herbs, probiotics, and microbial-based therapies)
  • Psychological (e.g., meditation, hypnosis, music therapies, relaxation therapies)
  • Physical (e.g., acupuncture, massage, spinal manipulation)
  • Combinations such as psychological and physical (e.g., yoga, tai chi, dance therapies, some forms of art therapy) or psychological and nutritional (e.g., mindful eating)

Nutritional approaches include what NCCIH previously categorized as natural products, whereas psychological and/or physical approaches include what was referred to as mind and body practices.

This publication looks at complementary health approaches that have been studied for cancer prevention, treatment of the disease, or symptom management, including what the science says about their effectiveness and any concerns that have been raised about their safety.

Incorporating Complementary Health Approaches Into Cancer Care

The Society for Integrative Oncology has issued evidence-based clinical practice guidelines for health care providers to consider when incorporating complementary health approaches in the care of people with cancer.

The guidelines state that, when used in addition to conventional therapies, some of these approaches help to control symptoms and enhance patients’ well-being. The guidelines warn, however, that unproven methods shouldn’t be used in place of conventional treatment because delayed treatment of cancer reduces the likelihood of a remission or cure.

Complementary Health Approaches for Cancer Symptoms and Treatment Side Effects

Some complementary health approaches may help people manage cancer symptoms or the side effects of treatment. However, some approaches may interfere with conventional cancer treatment or have other risks. People who have been diagnosed with cancer should consult their health care providers before using any complementary health approach.

Psychological and Physical Approaches


  • Several evaluations of the evidence have concluded that acupuncture can help manage treatment-related nausea and vomiting in people with cancer.
  • A 2020 combined analysis of 14 studies (920 participants) found that acupuncture was associated with significant reductions in cancer pain, both in studies where acupuncture was compared with sham (simulated) acupuncture and in studies where acupuncture was compared with no treatment. In two studies, the use of acupuncture or acupressure in addition to pain medicine helped people with cancer reduce their dose of pain medicine.
  • A 2018 review of 10 studies (1,327 participants) showed that acupuncture may be more helpful than sham acupuncture or usual care in relieving cancer-related fatigue.
  • Research on the effects of acupuncture on cancer-related hot flashes is limited.
  • Complications from acupuncture are rare, as long as the acupuncturist uses sterile needles and proper procedures. Chemotherapy and radiation therapy weaken the immune system, so it’s especially important for acupuncturists to follow strict clean-needle procedures to reduce the risk of infection when treating people with cancer.

More information on acupuncture


  • Hypnosis may be helpful for pain caused by cancer itself or by procedures used in cancer care, for nausea and vomiting in people with breast cancer, and for anxiety and distress around surgical and medical procedures in both adults and children. It may also be helpful for hot flashes in women with breast cancer.
  • Hypnosis is a safe technique when practiced by a trained, experienced, licensed health care provider.

More information on hypnosis

Massage Therapy

  • Massage therapy, with or without aromatherapy (the use of essential oils), has been used to attempt to relieve pain, anxiety, and other symptoms in people with cancer. However, there is only limited evidence on whether it is beneficial.
    • A 2021 review of 13 studies (1,100 participants) of various manual therapies, including but not limited to massage therapy, provided evidence for benefits on pain, physical function, and global well-being but not fatigue, nausea, anxiety, or depression. These results should be interpreted cautiously because a variety of different manual therapies and measurement techniques were included and because some studies included small numbers of participants or were of low quality.
    • A 2016 evaluation of 19 studies (more than 1,200 participants) of massage for people with cancer found some evidence that massage might help with pain and anxiety, but the quality of the evidence was very low, and findings were not consistent.
  • Massage therapists may need to modify their usual techniques when working with people with cancer; for example, they may have to use less pressure than usual in areas that are sensitive because of cancer or cancer treatments.

More information on massage therapy

Mindfulness-Based Stress Reduction

  • A 2020 review of 26 studies (3,476 participants) of people with various types of cancer showed that those who participated in mindfulness-based interventions had less anxiety, depression, fatigue, and stress, and a better quality of life than those who did not participate in mindfulness-based interventions.
  • Mindfulness and other forms of meditation are generally considered to be safe for healthy people. However, they may need to be modified to make them safe and comfortable for people with some health conditions. For example, if you can’t sit still comfortably for long periods of time, your meditation instructor can adapt the meditation practice so that you don’t need to do this.

More information on meditation and mindfulness

Tai Chi and Qigong

  • A 2020 review looked at 16 studies (1,268 participants) of tai chi in women with breast cancer. Some of the studies evaluated tai chi as an alternative to conventional supportive care interventions such as aerobic exercise and cognitive behavioral therapy, and others evaluated it as an addition to conventional care. Tai chi improved fatigue when used as an addition to conventional care (two studies) but not when used as an alternative to conventional care (two studies). Tai chi improved overall quality of life when used either as an addition to conventional care (four studies) or as an alternative to conventional care (two studies).
  • A 2019 review of 12 recent studies (915 participants) of qigong or tai chi for patients with various types of cancer found favorable effects on symptoms of fatigue and sleep quality that were large enough to be meaningful to patients.
  • Tai chi and qigong are generally considered to be safe practices.

More information on tai chi and qigong


  • A 2020 evaluation of 24 studies of yoga for women with breast cancer, involving a total of more than 1,600 participants, concluded that yoga provides small-to-moderate improvements in cancer-related fatigue and quality of life compared to interventions not involving physical activity. Therefore, it could be a supportive intervention for women with breast cancer, as an addition to standard treatment.
  • A 2021 review of 26 studies of yoga-based interventions for depressive symptoms (1,486 participants) and 16 studies of yoga-based interventions for anxiety symptoms (977 participants) in people with various types of cancer found evidence that the interventions were helpful for both types of symptoms. The majority of the studies involved women with breast cancer.
  • Yoga is generally considered a safe form of physical activity for healthy people when performed properly under the guidance of a qualified instructor. However, as with other forms of physical activity, injuries can occur. The most common injuries are sprains and strains. Serious injuries are rare. In studies of yoga in people with cancer, adverse events have mostly been minor. However, having an ongoing health problem such as cancer may increase the risks of doing yoga. If you have cancer, talk with your health care providers to find out whether any aspects of yoga might be unsafe for you.

More information on yoga

Nutritional Approaches


  • Ginger is an herb that is sold as a dietary supplement. A 2019 evaluation of 18 studies with more than 1,600 participants concluded that the evidence on whether ginger is helpful for nausea associated with cancer chemotherapy is mixed. Some studies suggested that ginger helped to control nausea, but in other studies, ginger didn’t seem to have any effect.
  • People diagnosed with cancer should consult their health care providers before taking ginger or any other dietary supplement.

More information on ginger

Complementary Health Approaches for Cancer Treatment

No complementary approach has been shown to cure cancer or cause it to go into remission. Some products or practices that have been advocated for cancer treatment may interfere with conventional cancer treatments or have other risks. If you’ve been diagnosed with cancer, you should consult your health care providers before using any complementary health approach.

The following sections discuss a few products that have been promoted as cancer treatments. You can find information on additional products at the NCI website.

Herbal Supplements

  • Studies on whether herbal supplements or substances derived from them might be of value in cancer treatment are in their early stages, and scientific evidence is limited. Herbal supplements may have side effects, and some may interact in harmful ways with drugs, including those used in cancer treatment.

Vitamin, Mineral, and Antioxidant Dietary Supplements

  • The effects of taking vitamin and mineral dietary supplements, including antioxidant supplements, during cancer treatment are uncertain. Because these supplements might interfere with the effectiveness of chemotherapy or other cancer therapies, if you are being treated for cancer, you should discuss their use with your health care providers.

Black Salves

  • Products called black salves have been marketed for self-treatment of a variety of skin conditions, including skin cancer. Black salves are neither safe nor effective. When used to treat a skin cancer, black salve products may not remove all of it, which may allow the cancer to spread and become more serious. Also, black salves can destroy both cancerous and healthy skin. They can cause scarring and tissue damage, which is sometimes severe and disfiguring. Most black salve research involves case studies; well-controlled clinical trials have not been conducted.


  • Laetrile is another name for the natural substance amygdalin, a chemical constituent found in the pits of many fruits. A 2019 review of research on laetrile found no clinical evidence it is effective as a cancer treatment. Laetrile can have toxic effects.

Intravenous Vitamin C

  • Studies on the benefit of high-dose, intravenous vitamin C use for cancer have yielded varying results. Research in people is limited; most of the evidence is based on animal and laboratory research. The evidence is mixed for intravenous vitamin C’s impact on tumor growth or overall survival. Some studies have found an increase in quality of life and a decrease in cancer treatment–related toxicities, but the findings are not conclusive.
  • Treatment with intravenous vitamin C generally seems to be well-tolerated and safe, but patients with certain conditions (e.g., iron overload, kidney disease) are at increased risk for serious toxicity.


  • Curcumin, a substance found in turmeric, has been studied for its possible effects on cancer development and progression. Because a variety of different products and dosages were tested, and because the studies were brief and included only small numbers of people, there isn’t enough evidence to recommend products that contain curcumin for the treatment of people with cancer.
  • Researchers are studying curcumin’s usefulness for alleviating side effects caused by cancer treatment, such as oral mucositis and radiation-induced dermatitis (a skin rash caused by radiation treatment), as well as quality of life.

Beware of Cancer Treatment Frauds

The U.S. Food and Drug Administration (FDA) has warned the public to beware of fraudulent cancer treatments promoted on websites or social media platforms.

Some fraudulent cancer treatments are harmful by themselves, and others can be indirectly harmful because people may delay seeking medical care while they try them, or because the fraudulent product interferes with the effectiveness of proven cancer treatments.

The people who sell fraudulent cancer treatments often market them with claims such as “treats all forms of cancer,” “cures cancer,” “selectively kills cancer cells,” or “more effective than chemotherapy.”                                     

If you’re considering using any anticancer product that you’ve seen in an advertisement, talk with your health care provider first.

Complementary Health Approaches for Cancer Prevention

You can reduce your risk of cancer in several ways—including making healthy choices (such as avoiding tobacco and maintaining a healthy weight), getting recommended vaccines against hepatitis B and human papillomavirus (HPV), and getting appropriate cancer screening tests. Research has also been done to see whether various nutritional approaches might help to prevent cancer.

Vitamin and Mineral Supplements

The U.S. Preventive Services Task Force—an expert group that makes recommendations about the types of health care people should receive to prevent diseases—evaluated the evidence on vitamin and mineral supplements and cancer prevention in 2014. (A 2021 update to the report is underway and is anticipated to give the same advice.) The recommendations state that:

  • You shouldn’t take vitamin E supplements to try to prevent cancer. Studies have shown that they don’t work.
  • You shouldn’t take beta-carotene supplements to try to prevent cancer. Studies have shown that they don’t work, and they can harm some people, such as those who smoke tobacco.
  • For all other vitamin and mineral supplements—including single vitamins or minerals, combinations such as calcium plus vitamin D, and multivitamins—there isn’t enough evidence to say whether they can help prevent cancer. The Task Force didn’t make a recommendation for or against the use of these supplements.


Green Tea

  • Studies of green tea and cancer in people have had inconsistent results. Based on current evidence, it isn’t possible to say whether green tea helps to prevent cancer.
  • Green tea is believed to be safe when consumed as a beverage in moderate amounts. Liver problems have been reported in a small number of people who took concentrated green tea extracts. Experts suggest that green tea extracts should be taken with food, people with liver problems should not take green tea extracts, and users should discontinue use and consult a health care provider if they develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes).

Other Nutritional Approaches

Several other dietary supplements, including garlic, Ginkgo biloba, noni, and grape seed extract, have been investigated for possible cancer-preventive effects, but the evidence on these substances is too limited for any conclusions to be reached.

In two large observational studies in which researchers kept track of people over a period of years, people who took glucosamine and chondroitin were less likely to develop colorectal cancer. Because these were observational studies, rather than trials in which people were randomly assigned to take a supplement or a placebo, the results can only provide clues for further research; they can’t prove a cause-and-effect relationship because other factors could be involved.

National Institutes of Health Research on Complementary Health Approaches for Cancer

Some ongoing studies related to complementary approaches and cancer funded by the National Center for Complementary and Integrative Health (NCCIH) or NCI are looking at:

  • Whether panaxynol, a substance from American ginseng, can suppress colitis and thereby lower the risk of colon cancer
  • The potential value of a multimodal mind and body intervention for reducing fear of cancer recurrence
  • Self-administered hypnosis to manage hot flashes (which may be caused by breast cancer treatment)
  • The potential value of yoga as a treatment for peripheral neuropathy, a painful side effect of some types of cancer chemotherapy

More To Consider

  • Gather information about the complementary health product or practice that interests you, and then discuss it with your health care providers. If you’ve been diagnosed with cancer, it’s especially important to talk with your health care providers before you start using any new complementary health approach. If you’re already using a complementary approach, tell your health care providers about it, even if your reason for using it has nothing to do with cancer. Here are examples of questions to ask:
    • What is known about the benefits and risks of this product or practice? Do the benefits outweigh the risks?
    • What are the potential side effects?
    • Will this approach interfere with my cancer treatment?
    • Can you refer me to a practitioner?
  • Don’t use any health product or practice that has not been proven safe and effective to replace conventional cancer care or as a reason to postpone seeing your health care provider about any health problem.
  • Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

Toll-free in the U.S.: 1-888-644-6226

Telecommunications relay service (TRS): 7-1-1


Email: (link sends email)

National Cancer Institute (NCI)

The National Cancer Institute is the Federal Government's lead agency for cancer research. The National Cancer Institute's Office of Cancer Complementary and Alternative Medicine coordinates and enhances the National Cancer Institute's activities in research on complementary health approaches.

Toll-free in the U.S.: 1-800-4-CANCER (1-800-422-6237)


Email: (link sends email)

NCI’s Office of Cancer Complementary and Alternative Medicine

NCI’s Office of Cancer Complementary and Alternative Medicine coordinates and enhances NCI’s activities in research on complementary health approaches.

Information on complementary health approaches in cancer treatment:


Know the Science

NCCIH and the National Institutes of Health (NIH) provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Know the Science features a variety of materials, including interactive modules, quizzes, and videos, as well as links to informative content from Federal resources designed to help consumers make sense of health information.

Explaining How Research Works (NIH)

Know the Science: How To Make Sense of a Scientific Journal Article

Understanding Clinical Studies (NIH)


A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.


NIH Clinical Research Trials and You

The National Institutes of Health (NIH) has created a website, NIH Clinical Research Trials and You, to help people learn about clinical trials, why they matter, and how to participate. The site includes questions and answers about clinical trials, guidance on how to find clinical trials through and other resources, and stories about the personal experiences of clinical trial participants. Clinical trials are necessary to find better ways to prevent, diagnose, and treat diseases.


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NCCIH thanks Jeffrey White, M.D., Oluwadamilola Olaku, M.D., M.P.H., Sophie King, M.S., and Megan Sansevere, M.S., of NCI’s Office of Cancer Complementary and Alternative Medicine, and David Shurtleff, Ph.D., of NCCIH for their review of the 2021 update of this publication.

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: October 2021