Herb and plant extracts

Aromatherapy is the use of concentrated natural oils extracted from plants. They are called essential oils. People believe that using these oils can help you feel better and improve your well-being.

Aromatherapy may be used with other complementary therapies such as massage. The oils may also be used:

• in baths
• as creams
• through diffusers
• in nasal inhalers (aroma sticks).

An aromatherapist will choose the oils they think will benefit you the most. For example, if you are having difficulty sleeping, they may choose an oil that is thought to help with relaxation and sleep.

Studies into the use of aromatherapy have shown varying results. Some studies have suggested that people using aromatherapy were less anxious, or had improved sleep and well-being.

You can buy essential oils in shops and online. But it is important to ask a qualified aromatherapist for advice before using essential oils at home. Some essential oils may interact with other medicines. It is important to talk to your cancer doctor if you wish to try aromatherapy. You also need to tell an aromatherapist about any treatment you are having or have recently had.

Aromatherapy oils need to be used with care as they are very concentrated and may cause harm if used incorrectly. They should only be used externally and be well diluted.

The International Federation of Aromatherapists has more information on its website, and a register of qualified aromatherapists. You can search this to find one in your area. The Complementary and Natural Healthcare Council (CNHC) also has a register of qualified aromatherapists.

Herbal medicines use plants or plant extracts to treat illnesses and promote health. Herbs may be used as part of traditional Chinese medicine. There are many different herbs that are used as herbal medicines.

Herbs can be:

• boiled in water and drunk as a tea
• mixed in an alcohol solution
• made into tablets, creams or ointments.

Examples of commonly used herbs:

• Ginger, which can be used to relieve feelings of sickness (nausea).
• St John’s wort, which can be used to treat a low mood and mild to moderate depression. It can interact with many prescription medicines. Always check with your cancer doctor or pharmacist before using it.

Some herbal therapies can interact with cancer treatments. For example, some can make cancer treatments less effective or increase their side effects. Examples include the following:

• St John’s wort affects many prescribed medicines. It can reduce the effectiveness of the chemotherapy drugs irinotecan and docetaxel.
• Green tea supplements may make the targeted therapy drug bortezomib (Velcade®) less effective. They can also increase the side effects of the chemotherapy drug irinotecan and the hormonal therapy tamoxifen.
• Garlic supplements and evening primrose oil may affect blood clotting. You should not use them before having surgery, as they may increase the risk of bleeding.

A herbal medicine may contain many substances. You may not know what all the active ingredients are. This means it is not possible to know all the possible effects the herbal medicine could have on other medicines or treatments.

Many doctors advise that you should avoid herbal medicines for a few weeks before, during and after cancer treatment.

If you take herbal medicines or are interested in taking them, it is important to talk to your cancer doctor or pharmacist. They need to know all the medicines you are taking and whether they are prescribed.

People may feel that taking herbal medicine will be safe as herbs are natural products. But this does not mean they are always safe. Natural substances can have strong side effects. Many medicines, including some chemotherapy drugs, are made from plants.

Something that might be safe in lower doses can be harmful in higher doses. For example, drinking green tea is generally safe but green tea supplements can contain much higher doses of certain substances. As well as interacting with some cancer drugs, green tea supplements can sometimes cause serious liver problems.

It is important to be aware of any side effects that herbal medicines may cause. And remember that some herbal medicines could interact with any medicines you take.

If you choose to take herbal medicines, it is best to buy only products that have the traditional herbal registration (THR) certification mark. This is a quality mark that shows the products have been tested for quality and safety. Herbal products that you buy in health food shops and pharmacies must meet quality standards.

Herbal products that are sold online or made for personal use do not have the THR mark. There are no checks on how these products are made or guarantees of what they contain and in what dose.

If you are visiting a herbalist, check that they are registered with an accredited body.

If you want to learn more about herbs, the Memorial Sloan Kettering Cancer Centre provides information about individual herbs, their uses and possible side effects.