Complementary medicines explained

Millions of Australians take complementary medicines each day. You can buy them in supermarkets, health food stores,  pharmacies, from complementary health providers and on the internet. Find out more about them, and how to use them safely.

Complementary medicines explained

Complementary medicines explained

Millions of Australians take complementary medicines each day. You can buy them in supermarkets, health food stores,  pharmacies, from complementary health providers and on the internet. Find out more about them, and how to use them safely.


What are complementary medicines?

Complementary medicines include:

  • natural and herbal medicines
  • alternative or holistic remedies
  • traditional remedies, including Chinese medicines
  • homeopathic preparations
  • aromatherapy oils
  • vitamins and minerals (although these can be part of medical treatment too)
  • some nutritional supplements, including some weight loss management products
  • bush medicines.

Like all medicines, complementary medicines can have benefits and side effects, cause allergic reactions, or interact with your other medicines. You need to use them with care.

Is it a medicine?

A lot of people don’t realise that complementary products are medicines too.

Medicines are things you take to change the way your body deals with illness or injury. They can also maintain your health.

They can come in many forms and can be applied onto your skin or into your body. These include herbs, tablets, liquids, powders, inhalers, drops, patches, creams, lotions, pessaries, suppositories or injections.

You can get them from a pharmacist, with or without prescription. You may also get them from supermarkets, health food stores, herbalists, naturopaths, complementary health providers and the internet.

Seek advice from a qualified person when choosing a complementary medicine. Ask about:

  • brands or forms that suit you
  • how much to take
  • how often to take it, and
  • what side effects and interactions to look out for.

As with all medicines, tell your health professional about any complementary medicines you are taking. That way, you can avoid the risk of harmful interactions with your other medicines.

You can use a medicines list to keep track of what you take. You can use a paper list or an app on your smartphone.

What dose should I take?

Complementary medicines can come in many strengths or doses. They may have more than one active ingredient. It can be hard to work out what is the best option or to compare with other brands.

Learn as much as you can about the medicine you are using. Find out what you can use it for. Read the label so you know the active ingredients it contains and the amount of each.

You may need to change from one brand of a complementary medicine to another. Be aware that the amount of any active ingredient may not be the same as your normal brand. This may mean the effect on any current medicines you might also take could be different. It may cause an interaction or effect that you didn’t have before.

Can I mix complementary and prescription medicines? 

Complementary medicines may not mix well with prescription medicines. They could make your prescribed medicine weaker or stronger than your doctor intends. That’s why it is vital to speak with your health professional. Tell them about any medicine that you take, complementary or otherwise.

An example: St John’s wort

St John’s wort is a plant (Hypericum perforatum) native to Europe and Asia. People have used it for mental health conditions for hundreds of years. You can get it as a herbal preparation in Australian pharmacies.

Make sure you tell your health professional if you are taking St John’s wort. This will help you avoid interactions with your other medicines.

St John’s wort mostly makes other medicines work less well. This is the case with:

  • birth control pills
  • warfarin and other medicines used to thin the blood
  • medicines for seizures
  • digoxin, a medicine used for heart conditions
  • HIV medicines
  • cancer medicines
  • medicines used to prevent rejection after an organ transplant
  • asthma medicines.

St John’s wort may interact with some antidepressants and migraine medicines. It raises the risk of side effects.

St John’s wort has shown some benefit in trials for mild to moderate depression. It hasn’t shown benefit for more severe depression. Make sure you talk to your health professional if you think you are depressed. They will help you get the best treatment for your needs.

Like all medicines, St John’s wort can also have side effects. The most common side effects of St John’s wort are:

  • dry mouth
  • feeling dizzy
  • loose bowel movement (diarrhoea)
  • feeling the urge to vomit
  • increased sensitivity to sunlight
  • feeling tired.

Taking alcohol with St John’s wort may also increase certain side effects like feeling dizzy.

Learn more about Hypericum on Medicine Finder

How effective are complementary medicines?

High quality trials have tested some complementary medicines to show that they work well, but most have not been tested in this way.

Complementary medicines go through less testing than prescription and over-the-counter medicines do before they can be sold in Australia. This means we know less about how they work, their side effects and interactions.

Makers of complementary medicines sold in Australia still have to comply with quality and safety standards for their products. They need to have some evidence to back up their claims.

You can find out more on the Government rules for complementary medicines sold in Australia.

See the Therapeutic Goods Administration’s webpage on the regulation of complementary medicines in Australia.

An example: fish oil

One complementary medicine that has been tested is fish oil. 

Some fish oils are high in omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Trials show that these fish oils can:

  • lower triglycerides
  • raise high-density lipoprotein (HDL) cholesterol (the good cholesterol).

Your health professional might recommend fish oil if you have high triglyceride levels.

Where can I find good information on complementary medicines?

There are thousands of websites about complementary medicines. Their purpose is often to sell products. The content they provide may not be correct.