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Home > Understanding Breast Cancer > Safety and Complementary Therapy


Safety and Complementary Therapy


Safety is a main concern for both standard medical treatments and complementary therapies. However, unlike conventional medicine, many complementary therapies are not regulated as tightly by the federal government and may not have the same quality controls.

Data on safety

One reason for concern is the lack of good scientific evidence on the safety of many complementary therapies. This can make it hard to know which therapies (and at what doses and frequencies of use) are likely safe to use and which may be harmful.

Any complementary therapy should be approached with caution. While a few therapies have a good record of safety (like acupuncture and massage), some are known to be unsafe (like kava), and others are simply unknown. 

Even those therapies generally considered safe may not be safe for everyone. For example, some therapies can be harmful for people undergoing certain cancer treatments or those who have underlying medical conditions, like malnutrition or blood clotting problems (see below).  

Potential for misuse and harmful interactions

Before using any complementary therapy, talk to your health care provider. Your provider can help you avoid using a therapy (or a dose of a therapy) that may be harmful to you.

Some complementary therapies, including certain herbs and supplements, may interfere with chemotherapy, hormone therapy, radiation therapy or other medicines or radiation therapy you might take during treatment [20-22]. For example, echinacea (and other supplements) may interfere with certain chemotherapy drugs. Herbs, such as garlic and ginkgo, can cause excessive bleeding and other complications during surgery [20,23]. And, some therapies that may be safe at lower doses are harmful in higher amounts. So, it is very important to talk with your provider about any complementary therapy you are thinking of using to avoid harmful interactions.

Finding safety information

Along with talking to your health care provider, you can do your own research. This section of Understanding Breast Cancer has detailed information describing many complementary therapies. The National Center for Complementary and Alternative Medicine also has information on many therapies.

A good resource to search for scientific articles on complementary therapies is the National Library of Medicine’s PubMed website.

“Natural” vs. “safe”

Although the idea of "natural" products is appealing, "natural" does not mean "safe" (think about poison ivy, poisonous mushrooms and rattlesnakes). The Food and Drug Administration (FDA) has some oversight on dietary supplements, but it regulates them much less strictly than medical drugs. The FDA requires strong evidence on the safety and effectiveness of medicines before they can be prescribed and sold in the United States. However, the FDA doesn't require this level of evidence for the safety or effectiveness of supplements and other over-the-counter health products.

If the FDA has evidence that a “natural” product is harmful, it can pull the food or supplement from the market or issue a warning. To see if any safety alerts have been issued on a product, visit the FDA or Federal Trade Commission (FTC) websites. Before using any complementary therapy, do your research and check with your health care provider.

Wild claims

The Internet, supermarket aisles and late night infomercials are filled with products that claim to do just about everything. More often than not, this is a sign a product is not effective and, more importantly, could be unsafe. No complementary therapy has been proven to cure cancer. If a complementary therapy is said to cure cancer, do your research. This type of claim is a sign that a product or therapy is a scam. There is no one treatment for all types of cancer or even all types of breast cancer.

If you see a wild claim, you can check what the scientific evidence shows by searching for articles on the National Library of Medicine’s PubMed website. Your health care provider is also a good source for this information.

If you suspect a product or therapy is making a false claim that it prevents or cures cancer, check the FTC's Cancer Treatment Scams website for any consumer warnings.

For more information on spotting or reporting false claims, visit the FTC website.

Unknown contents

The manufacture, distribution and sale of herbs and other dietary supplements are much less regulated than medical drugs. So, there’s little guarantee what is listed on the label of a bottle of supplements is what’s actually inside the bottle.

When choosing supplements, go with a known, reputable manufacturer to increase the likelihood that the:

  • Supplement listed on the label is inside the bottle
  • Dose and potency are listed correctly
  • Supplement is free of harmful contents, like pesticides and heavy metals (such as lead, arsenic or mercury)
  • Supplement is safely manufactured

One way to check that a manufacturer follows good practices in preparing supplements is the “USP verified” stamp on the label. This stamp means the manufacturer of the supplement paid to have its product carefully tested for integrity, purity and safe manufacturing by the U.S. Pharmacopeia (USP). Visit the USP website to see if a supplement has been USP verified.

Find a list of resources on safety information for complementary therapies.

Updated 02/03/14

Is it Effective? Is it Safe? The Importance of Scientific Evidence  
 Finding a Complementary Therapy Provider  next