Research published in the Journal of Forensic Sciences has examined the risks of herbal medicines, finding some can be dangerous and even lethal.

University of Adelaide forensic pathologist Roger Byard found some herbal products were contaminated, others posed serious health risks and many common herbs could cause severe side-effects when used with conventional medicine.

RMIT University complementary medicine expert, Professor Marc Cohen, says while there could be dangers involved with the use of herbal medicines, these should not be overstated.

We need to keep perspective - the risks associated with herbal medicines have to be compared to the severe side-effects suffered each year by people taking pharmaceutical drugs, Professor Cohen said.

While contamination is a serious issue, very few people are affected by contaminated herbal medicines.

Compare this to food contamination, which leads to thousands of people falling ill with food poisoning every year.

Herbal medicines may be natural but they are potent and it is vital for practitioners in the industry to be highly trained, to ensure they are well versed in possible side-effects and the risks of interactions with other drugs.

There are significant risks when mixing herbal medicines with conventional drugs and people taking any kind of natural supplement must be encouraged to disclose this to their doctor.

Professor Cohen is the co-author, with RMIT's Dr Lesley Braun, of Herbs and Natural Supplements: An Evidence-Based Guide (3rd Edition, Elsevier Science, 2010).

He is an Expert Advisor to the Therapeutic Goods Administration's Complementary Medicine Evaluation Committee and a member of the National Institute of Complementary Medicine Consultative Committee and the National Health and Medical Research Council Grant Review Panel.

The Foundation Professor of Complementary Medicine at RMIT, he is available for interview on the potential dangers, risks and side-effects of herbal medicines.

For interviews: RMIT University's Professor Marc Cohen, (03) 9925 7440 or 0439 446 688.

For general media enquiries: RMIT University Communications, Gosia Kaszubska, (03) 9925 3176 or 0417 510 735.