Traditional Chinese medicines (TCMs), part of the growing global trend to increased use of herbal and complementary medicines, may lose some of its glow after new Australian research found the products contained traces of pharmaceuticals, heavy metals, stimulants and even the DNA of endangered animals.

According to a study by Australian university researchers from Curtin University, Murdoch University and the University of Adelaide, published in Scientific Reports journal online December 10, 2015, 90 percent of 26 widely available traditional Chinese medicines tested from retail stores available nationally in Australia were not fit for human consumption.

Half contained illegal substances, including toxic metals, prescription medications, stimulants and animal DNA, none of which were listed on the product’s label.

TCMs are a multi-billion-dollar industry, and it is estimated 50 per cent of Australians have used alternative therapies at some point.

Researchers employed a new method involving highly sensitive DNA sequencing, toxicology, and heavy metal testing to assess the composition of the TCMs.

“If we don’t know what’s in them, it’s very difficult to predict the interactions, and it’s obviously of great concern if they are given to children or pregnant women, the potential outcomes there are very serious, said Murdoch University biochemist Dr. Garth Maker, one of the study researchers.

Curtin University lead researcher Professor Michael Bunce was shocked by the results. “Half of them have illegal ingredients in them, we’ve determined from DNA, half of them have pharmaceuticals added to them that are clearly synthetic in nature and have not come from natural compounds,” he said.

“Another proportion of them have heavy metals beyond the safe ingestion recommendations … 90% of them are not fit for human consumption.”

Dr. Maker said contamination by undisclosed pharmaceuticals was a health concern. Over-the-counter drugs like paracetamol and ibuprofen were found, and also steroids, blood thinner warfarin, and sildenafil, the active ingredient in Viagra.

One product contained over ten times the recommended daily limit for arsenic exposure while another contained strychnine, which is used as a rat poison and at lower levels as a performance-enhancing drug.

Professor Bunce said each herbal medicine sold in Australia needs to be listed with the Therapeutic Goods Administration (TGA), but only 12 of the products tested were registered with the agency and were deemed “low-risk.”

The remaining 14 were not registered by the TGA and, therefore, should not be available to Australian consumers in a commercial quantity, he said.

To make a true declaration of the ingredients, the TGA relies on the importer an honesty system that researchers believe is being exploited.

A TGA spokeswoman said that the medicines are complementary because they may only contain pre-approved low-risk ingredients and must not make claims or imply that they have benefited from the treatment or prevention of a serious illness.