Taking herbal medicine: tips and safety information

Below are some helpful tips for people with cancer who are thinking about taking herbal medicine, and some safety information for taking herbs if you are going through treatment.

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Helpful tips

  • Buy or use herbal products from qualified practitioners or reputable suppliers.
  • Ask for products that are clearly labelled in English with your name, batch number, date, quantity, dosage, directions, safety information (if applicable) and your practitioner’s contact details.
  • Avoid self-prescribing with over-the-counter products from a health food shop, pharmacy or the internet. Be aware that products from other countries that are sold over the internet are not subject to the same quality and safety regulations as those sold in Australia. Some Ayurvedic and Chinese products may contain lead, mercury and arsenic in high enough quantities to be considered toxic.
  • Make sure you know how to prepare and take your herbs. Like conventional medicine, taking the correct dose at the right time is important for the herbal remedies to work safely. Talk to your doctor and complementary health practitioner, or call NPS MedicineWise’s Medicines Line on 1300 633 424 from anywhere in Australia, Monday to Friday, 9am to 5pm AEST. This service is staffed by registered nurses who provide confidential, independent information about prescription, over-thecounter and complementary medicines.
  • Ask the practitioner for ways to mask the taste of the herbs if you find them bitter.
  • If you suspect you have had an adverse reaction to any kind of medicine, speak to your practitioner or call the NPS MedicineWise Adverse Medicine Events Line on 1300 134 237. If the reaction is serious, call 000 or go to your nearest emergency department.

Safety of taking herbs during treatment

Many people believe herbs are safe simply because they are natural. This is not true. Taking the wrong dose, the wrong combination or using the wrong part of the plant may cause serious side effects or toxicity.

Herbs can also cause harmful interactions when used with chemotherapy, radiation therapy and hormone therapy. Ask your treatment team which herbs and supplements are suitable to take during cancer treatment.

St John’s wort – This popular herb for mild to moderate depression has been shown to stop some chemotherapy drugs and other medications from working properly. It may also increase skin reactions to radiation therapy. If you are feeling depressed, ask your doctor about other treatments.

Black cohosh – Herbalists often prescribe this to menopausal women who are experiencing hot flushes. While clinical trials show that black cohosh is relatively safe, it should not be used by people with liver damage. There is not enough scientific evidence to support the use of black cohosh in people with cancer.

Ginkgo biloba and garlic – Studies have shown that these may have a blood-thinning effect, which can cause bleeding. This could be harmful in people with low platelet levels (e.g. from chemotherapy) or who are having surgery.

Green tea – This has been shown to stop the cancer drug bortezomib (Velcade®) from working properly. Keep your complementary therapists and other health professionals informed about any herbal remedies you use before, during or after cancer treatment. Knowing all this information will help them give you the best possible care.

This information was last reviewed in May 2015
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