More than 3 million Americans are chronically infected with Hepatitis C: a virus that can lead to cirrhosis, liver failure and liver cancer.

A good percentage of patients do not respond to traditional treatments or have other conditions that prevent their use.

In many of these cases, they turn to alternative medicines.

Milk Thistle extract is a popular botanical product that is often taken.

A new study in the Journal of the American Medical Association looks at the effectiveness of the supplement. Researchers included 154 people with chronic Hepatitis C who were unsuccessfully treated with interferon therapy.

The participants received milk thistle or a placebo 3 times a day for 24 weeks. Blood tests were done to measure liver damage and response to the treatment.

The conclusion, milk thistle extract, even at higher than normal doses, did not improve liver function more than the placebo.

Hepatitis C is one of the most common causes of chronic liver disease. You can find out more about preventing infection by visiting the National Institutes of Health website.

I'm Dr. Cindy Haines of HealthDay TV, with the news that doctors are reading; health news that matters to you.