Experts have issued a warning that herbal medicines if consumed in large quantities, injected, or combined with prescription drugs, can be extremely dangerous.
Professor Roger Byard, University of Adelaide, highlighted the highly toxic nature of many herbal substances that often mistakenly considered safe.
The forensic pathologist said: "There's a false perception that herbal remedies are safer than manufactured medicines, when in fact many contain potentially lethal concentrations of arsenic, mercury and lead.
"These substances may cause serious illnesses, exacerbate pre-existing health problems or result in death, particularly if taken in excess or injected rather than ingested."
The expert also warned against the risks arising from the interaction between herbal medicines and prescription drugs that could lead serious health damage, including liver, renal and cardiac failure, strokes, movement disorders, muscle weakness and seizures.
Professor Byard said: "Herbal medicines are frequently mixed with standard drugs, presumably to make them more effective. This can also have devastating results."
The study was published in the US-based Journal of Forensic Sciences.