Complementary and alternative therapies for cancer treatment

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Many people will consider the use of complementary and alternative therapies when undergoing cancer treatment, but not all of these are safe to use. Find out what you need to consider before using complementary or alternative therapies for cancer treatment.

Key points

  • Conventional therapies are ones recommended by your health-care team based on scientific evidence.
  • Complementary therapies are used with conventional therapy, while alternative therapies are used instead of conventional therapy.
  • Types of complementary and alternative therapies include homeopathic and naturopathic medicine, ayurveda and mind-body medicine.
  • Supplements and herbal products are not always safe to use as they may interact with your cancer treatment or your other medications.
  • Do your research and always speak to your health-care team before trying any complementary or alternative therapies.

Many people think about or use complementary and alternative therapies to help treat or prevent illness. Maybe you or your family have too. This section contains information to help you understand and potentially benefit from complementary and alternative therapies. It also contains tips to help you stay safe if you choose to use them.

What are complementary and alternative therapies?

Complementary and alternative therapies are health-care systems, practices and products that are separate from conventional therapy. Conventional therapies are the ones recommended by doctors, nurses, physiotherapists and the rest of your health-care team and are based on scientific evidence. Examples of conventional cancer therapies are chemotherapy and radiation.

Sometimes complementary or alternative therapies are tested scientifically and are proven safe and effective. They may then be considered for use as a part of conventional therapy.

What’s the difference between complementary therapy and alternative therapy?

  • Complementary therapy is used with conventional therapy. It does not try to treat cancer but can help you cope with the conventional treatment or side effects. An example might be using aromatherapy to manage treatment side effects.
  • Alternative therapy is used instead of conventional therapy. An example would be replacing all of your prescribed chemotherapy medications with a special diet and vitamins.

Types of complementary and alternative therapies

  • Homeopathic medicine is the treatment of illnesses using very small doses of substances such as plant, mineral or animal extracts. These doses are thought to help the body heal itself.
  • Naturopathic medicine is the use of natural (vitamins, herbals, probiotics and so on) and other non-medical remedies to treat illnesses.
  • Traditional Chinese medicine includes a range of practices that started in China over several thousand years ago. These practices include herbal medicine, acupuncture, massage and Qigong (a type of exercise).
  • Ayurveda is an ancient healing practice that started in India. It promotes balance between the mind, body and soul.
  • Mind-body medicine includes meditation, hypnosis, yoga and prayer.
  • Manipulative include chiropractic, osteopathy, reflexology and massage. Chiropractic treatments focus on adjusting the spine and manipulating the other joints and soft-tissues. Osteopathy involves certain manual and physical treatments to treat back and neck pain. Reflexology uses pressure points in the body to promote healing.
  • Energy medicine includes energy field and bio-electromagnetic-based treatments such as magnets. Energy therapies focus on the energy fields thought to exist in and around the body.

Dietary supplements and herbal products

A dietary supplement contains ingredients that add to your diet. These ingredients may be vitamins, minerals, herbs or other plant materials, amino acids, probiotics or enzymes. Supplements may come in pill, capsule, powder or liquid form. They may be sold in a grocery, health food or drug store. You can also buy them online, through TV sales channels or directly from the company. They might be used as part of naturopathic, homeopathic or Chinese medicine.

Some dietary supplements have been proven effective for certain conditions. However, many supplements claim to treat or even cure cancer. Unfortunately, there is usually no scientific evidence to support these claims.

'Natural' doesn't always mean 'safe'

There are many safe and effective supplements that come from natural sources such as plants. Many conventional medicines also come from natural sources. However, 'natural' does not always mean 'safe'. Natural products can have side effects too. Some supplements can even harm your body. For example, the herbs kava and comfrey have caused severe liver damage.

Dietary supplements can be regulated by the government as 'foods'. This means they do not need to meet the same safety and effectiveness standards as medications do. Some supplements can even be toxic or dangerous. Studies have found that many bottles of commonly available supplements:

  • did not contain the ingredients listed on the label
  • had very little of the active ingredient
  • contained dangerous substances such as heavy metals, prescription drugs, or pesticides (chemicals to kill bugs)

How can I tell if a complementary or alternative therapy is safe?

Not all complementary and alternative therapies are dangerous and many people find them helpful. But to be safe, it’s important that you talk to your doctor, nurse or pharmacist before starting any of these therapies while you are in treatment.

Some of these therapies may actually interfere with your standard medical treatment by:

  • preventing your conventional therapy from working very well
  • interacting with your other treatments and causing toxic side effects
  • potentially causing side effects that may worsen signs and symptoms of standard treatment
  • affecting test results that are used to monitor your cancer

For these reasons, it’s very important to keep your health care team informed!

You might think that the people on your health-care team don’t want you to try complementary or alternative therapies. Because of this, you might feel uncomfortable talking to them about it. Remember that the people on your health-care team want what is best for you. Share with them the reasons you want to try complementary and alternative therapies; usually you can find a way to work together.

It is your body and it is your right to choose what you do. At the same time, if your health-care team knows each of the therapies you are doing, they will be better able to help you. They can make sure that a complementary or alternative therapy isn’t interfering with your conventional therapies.

Do some research!

When you’re considering something as important as your health it’s important to know the facts. You and/or your parent/caregiver should do a bit of research first. Don’t try a therapy because you saw an ad or someone told you that it worked for them. Find out whether scientific studies published in peer-reviewed journals support the claims made for that therapy.

Learn about the treatment's risks, potential benefits and scientific evidence. This is critical to your health and safety. Scientific research on many therapies is relatively new. This kind of information may not be available for every therapy. However, many studies on treatments are under way. Our knowledge and understanding of complementary and alternative therapies is increasing all the time. To find out more about current therapies, check out the National Centre for Complementary and Integrative Health website:

Here are some tips to help you determine if the website is of good quality. Remember SCREEN!

S = SourceWho wrote the information or hosts the website? Check out their credentials. One way to do this, though it’s not 100% accurate, is by looking at the domain. Is the site from the government (.gov), educational (.edu), or from a non-profit organization (.org)? Is the site up to date? What is the last date it was updated?
C = Conflict of interest or biasIs the site selling or promoting a product or service? If it is, the person or group behind the site might have bias or only show one side of the story.
R = editorial Review processDid someone such as an editor or a group of experts read this information and then publish or comment on it? Is there an editorial process or seal of approval? Having a review adds credibility.
E = Evidence-basedAre claims based on scientific research and is there documentation? In other words, can the person or group prove them? If they make a claim, they should show you evidence to back it up.
E = Extreme claimsDoes the site claim 'miracles', 'amazing results' or 'earthshaking breakthroughs'? Any claim that a treatment works for dozens of different problems or leads to 99% improvement is likely to be misleading and driven by a desire to make money.
N = Not relatedIs the information unrelated to or different from what you were told by your health-care provider? If so, you should do more research.

Before you try a therapy

  • Talk to your health-care team. Show them the results of your research and get their opinion. Ask them any questions you might still have. They have special training in understanding research studies.
  • Find out about the person giving the therapy. What kind of training do they have? How many times has this person given the therapy? Ask whether they belong to an organized group of some kind. A trustworthy therapist will be more than happy to answer these questions for you.
  • Find out how much the treatment will cost. Also see if your insurance will cover it!


Beware of alternative medicine practitioners who say they can cure diseases that do not respond to standard medical practice. Sadly, research shows that this is usually not true.

Last updated: September 3rd 2019