January 2017 Health Bulletin

Do herbal products have risks for the Australian community?

Often people assume herbal preparations are safe because they are “natural”, however the risks to the Australian community from these products are largely unknown because of the lack of regulation, quality control, labelling of ingredients and interactions with conventional and other herbal preparations.

South Australian researches have published in The Medical Journal of Australia suggesting manufacturers of complementary and alternative medications be subject to independent testing of samples, policing of inaccurate claims made on labels and websites, and be held legally accountable for compliance with regulations.

Problems with herbal medicines

1. Addition of prescription medications to herbal preparations occurs, presumably to enhance the apparent effect of the herbal preparation. These are generally not mentioned on the label. Issues involve overdosing (particularly if used with prescribed medication), allergies and side effects due to uncontrolled administration of these pharmaceuticals. The types of drugs that have been added to herbal preparations include anti-epileptic drugs, antibiotics, antihistamines, steroids, diabetes medications and others.

2. Substitution of the plant species can result in toxic effects. Replacement with a less expensive more harmful variety occurs, as well as preparations confusing plant types, as herbs can have different names in different regions. Poisoning leading to liver, gut, kidney and neurological damage have been reported relating to substitution.

3. Presence of toxic substances have been found in herbal preparations from heavy metals such as arsenic, lead and mercury to pesticides such as DDT and organochlorine preparations. Toxic materials may be added or be a natural part of a plant or animal product used. Effects such as liver damage, heart arrhythmias, stroke and seizures have been reported.

4. Purification of the herbs are sometimes inadequate and contamination may cause adverse reactions such as heart problems occurring with the Chinese herb preparation containing aconite.

Interactions with prescribed and over the counter medications

Some interactions of herbal preparations with conventional medications are well documented but there are many others that remain unknown. There may be an enhancement or reduction of efficacy of prescribe drugs, and unpredictable effects. Herbal preparations might affect some laboratory assays, altering test results.


In some Australian studies less than 50% of patients tell their doctor about their use of herbal preparations.
One in 20 complementary medicines fail Australian quality control measures relating to essential composition and recent evidence shows adulteration with pharmaceuticals, and products with inaccurate ingredient lists.

The researchers suggest that state and federal governments and regulatory bodies should respond to this matter with some urgency because of the risk of adverse reactions relating to the use of herbal preparations.

What risks do herbal products pose to the Australian community? Roger W Byard, Ian Musgrave, Garth Maker and Michael Bunce Med J Aust 2017; 206 (2): 86-90.

Information provided might not be relevant to a particular person's circumstances and should always be discussed with that person's own healthcare provider.