Prof. Ernst and colleagues reviewed the evidence and they aren’t sanguine.

First, the details.

  • 26 systematic reviews were included.

And, the results.

  • Most common herbal medicine product contaminants:
    • Dust
    • Pollens
    • Insects
    • Rodents
    • Parasites
    • Microbes
    • Fungi
    • Mold
    • Toxins
    • Pesticides
    • Toxic heavy metals
    • Prescription drugs
  • The most severe adverse effects caused by these adulterations:
    • Agranulocytosis: severely lowered white blood cell count
    • Meningitis
    • Multi-organ failure
    • Perinatal stroke
    • Arsenic, lead, or mercury poisoning
    • Malignancies or carcinomas (cancer)
    • Hepatic (liver) encephalopathy
    • Hepato-renal syndrome: progressive kidney failure in a person with cirrhosis of the liver
    • Kidney toxicity
    • Rhabdomyolysis: breakdown of muscle leading to kidney failure
    • Metabolic acidosis: body produces too much acid for the kidney’s to remove
    • Kidney or liver failure
    • Cerebral edema
    • Coma
    • Intracerebral hemorrhage (stroke)
    • Death
  • Adulteration and contamination of herbal medicine products were most commonly noted for traditional Indian and Chinese remedies, respectively.

The bottom line?

The authors concluded, “Collectively these data suggest that there are reasons for concerns with regards to the quality of herbal medicine products.”

Adulteration and contamination can cause serious adverse effects. More stringent quality control and enforcement are needed to minimize these health risks.

How common is it? The American Association of Poison Control Centers provides some perspective here.

8/1/12 10:32 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.