Herbal remedies, also known as botanical medicine, have been used in many traditional medicine systems. They are produced from all parts of a plant including the roots, leaves, berries and flowers. These may contain active ingredients that can cause chemical changes in the body. Herbal remedies can be taken by mouth or applied to the skin to treat disease and promote health. Sometimes herbs and plants are categorised as biological treatments.
Many scientific studies have examined the effects of various herbs on people with cancer. While some remedies have been shown to reduce side effects of cancer treatment, many remedies aren't supported by research.
Some herbs may interact with conventional cancer treatment or medicines, and change how the treatment works or the dose is absorbed. Herbs taken in large quantities can be toxic. For more information on the effects of specific herbs and botanicals, visit the Memorial Sloan Kettering Cancer Center website at mskcc.org and search for "herbs". You can also download their About Herbs app from iTunes.
Do herbs cure cancer?
There is no reliable scientific evidence that herbal remedies alone can cure or treat cancer. However, some plant extracts have been found to have anti-cancer effects and have been turned into chemotherapy drugs. These include vincristine from the periwinkle plant, and taxanes from the bark of the Pacific yew tree.
Medical use of cannabis
Some people are interested in using cannabis for medical purposes. Cannabis is a plant that contains many types of chemicals called cannabinoids. These chemicals act on certain receptors found on cells in our body. Cannabinoids can also be made in a laboratory.
Medicinal cannabis contains standard measures of cannabinoids. Two cannabinoids commonly used in medicinal cannabis are delta‑9-tetrahydrocannabinol (THC) and cannabidiol (CBD).
There is no evidence that medicinal cannabis can treat or cure cancer itself.5 Research studies have looked at the potential benefits of using medicinal cannabis to relieve cancer symptoms and treatment side effects. There is some evidence that cannabinoids can help people who have found conventional treatment unsuccessful for some symptoms and side effects (e.g., Chemotherapy-induced nausea and vomiting).
To date, published studies have shown medicinal cannabis to have little effect on appetite, weight, pain or sleep problems. Research is continuing in this area.
It is illegal to grow, possess or use cannabis in Australia. However, the Australian Government allows seriously ill people to access medicinal cannabis for medical reasons through registered medical practitioners. Most medicinal cannabis products in Australia are unapproved products. This means that before prescribing medicinal cannabis, your doctor needs to get approval from the government. The laws about access to medicinal cannabis vary in each state and territory. These laws may affect whether it can be prescribed for you.
The TGA now allows low dose cannabis products containing up to 150 mg of CBD to be included on the ARTG and sold over the counter by pharmacists. As at 2023, no product has been approved by the TGA.
Medicinal cannabis may interact with some other drugs and also affect your driving ability. Talk with your doctor about any precautions you should take.
For more information, visit tga.gov.au and search for “medicinal cannabis”.
Western herbal medicine
What it is
Western herbal medicines are usually made from herbs traditionally grown in Europe and North America, but some come from Asia.
Why use it
Herbal medicines are often used to help with the side effects of conventional cancer treatments, such as lowering fatigue and improving wellbeing. Evidence shows they should be used in addition to conventional therapies, rather than as an alternative.
What to expect
After taking a case history, the practitioner puts together a holistic picture of your health. They will look for underlying reasons for your ill health or symptoms, and dispense a remedy addressing the causes and symptoms of your illness. They may give you a pre-made herbal formula or make up a blend of herbs specifically for your needs. Herbal medicines can be prepared as liquid extracts taken with water or as a tea (infusion), or as creams or tablets.
There is a wide body of research into the effectiveness and safety of many herbs, and some studies show promising results. Speak to your doctor and herbal medicine practitioner about the potential side effects of any herbal preparations.
Many pharmacies and health food stores sell herbal preparations. Ask your complementary therapist or pharmacist if these are of high quality and meet Australian standards.
Tips for using herbal products safely
Buy herbal products from a qualified therapist or reputable supplier.
If your therapist is making up a preparation for you, ask for it to be clearly labelled in English with your name, date, quantity, ingredients, dosage, directions, safety information (if applicable) and your therapist’s contact details.
Avoid buying over-the-counter products online. Products from other countries that are available over the internet are not covered by the same quality and safety regulations as those sold in Australia and may not include the ingredients listed on the label.
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 safe use of herbal remedies.
Check the label for any warnings about side effects and drug interactions. Talk to your doctor and complementary therapist about possible side effects and what you should do if you experience them.
Report any suspected adverse reactions to any kind of medicine to your therapist or doctor. If the reaction is serious, call Triple Zero (000) or go to your nearest emergency department.
Chinese herbal medicine
What it is
Chinese herbs are a key part of TCM. Different parts of plants, such as the leaves, roots, stems, flowers and seeds, are used. Herbs may be taken as tablets or given as tea.
Why use it
Herbs are given to unblock meridians, bring harmony between Yin and Yang, and restore organ function.
What to expect
The practitioner will take a case history and may do a tongue and pulse analysis to help them assess how your body is out of balance. They will choose a combination of herbs and foods to help bring your body back into balance. Chinese herbalists make a formula tailored specifically to your condition, or they can dispense prepackaged herbal medicines.
As with Western herbal medicine, many Chinese herbs have been scientifically evaluated for how well they work for people with cancer. Studies have found benefits for some herbs, such as American ginseng for cancer-related fatigue. Research is continuing to examine the benefits of different herbs and different herbal combinations.
Chinese herbal medicine is a complex area and it's best to see an experienced practitioner rather than trying to treat yourself. Some herbs may interact with some cancer treatments and medicines, and cause side effects. See below for tips on using herbs safely.
Taking care with herbs during treatment
Although herbs are natural, they are not always safe. Taking the wrong dose or wrong combination or using the wrong part of the plant may cause side effects or be poisonous (toxic). Also, herbs used with chemotherapy, radiation therapy and hormone therapy can cause harmful interactions. All herbs should be prescribed by a qualified practitioner.
Some Ayurvedic and Chinese products have been shown to contain lead, mercury and arsenic in high enough quantities to be considered toxic. Other herbal preparations have been found to contain pesticides and prescription medicines.
St John's wort
This popular herb for mild to moderate depression has been shown to stop some chemotherapy drugs and other medicines from working properly. It may also increase skin reactions to radiation therapy. If you are feeling depressed, ask your doctor about other treatments.
Herbalists often prescribe this herb 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 bloodthinning effect, which can cause bleeding. This could be harmful in people with low platelet levels (e.g. from chemotherapy) or who are having surgery.
This has been shown to stop the cancer drug bortezomib (brand name 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. This information will help them give you the best possible care.
What they are
Also known as flower essences, these are highly diluted extracts from the flowers of wild plants. There are many types of flower remedies from around the world. The most well known in Australia are the Original Bach Flower Remedies, developed in the 1930s in England, and Australian Bush Flower Essences, developed in Australia in the 1980s.
Why use them
Flower remedies are used to balance the mind, body and spirit, and help you cope with emotional problems, which can sometimes contribute to poor health.
What to expect
Much like a counselling session, the therapist will ask questions and listen to you talk about yourself, the problems you are experiencing and how you feel about or approach certain situations. This enables the therapist to prepare a remedy – usually a blend of essences – tailored specifically for you, which is taken in water several times a day.
Scientific evidence does not support the use of flower remedies for treating diseases. However, anecdotal evidence suggests they may be helpful for reducing fear, anxiety or depression.
"After surgery, I was so fearful that the cancer would return. My naturopath gave me Bach Flower Remedies for fear, shock and exhaustion. These helped me relax and I became more realistic about my situation." - Louise (bowel cancer)
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Expert content reviewers:
Suzanne Grant, Senior Acupuncturist, Chris O'Brien Lifehouse, NSW; A/Prof Craig Hassed, Senior Lecturer, Department of General Practice, Monash University, VIC; Mara Lidums, Consumer; Tanya McMillan, Consumer; Simone Noelker, Physiotherapist and Wellness Centre Manager, Ballarat Regional Integrated Cancer Centre, VIC; A/Prof Byeongsang Oh, Acupuncturist, University of Sydney and Northern Sydney Cancer Centre, NSW; Sue Suchy, Consumer; Marie Veale, 13 11 20 Consultant, Cancer Council Queensland, QLD; Prof Anne Williams, Nursing Research Consultant, Centre for Nursing Research, Sir Charles Gairdner Hospital, and Chair, Health Research, School of Health Professions, Murdoch University, WA.