Johnson & Johnson will lower the maximum daily dosage in order to lessen acetaminophen overdoses, McNeil Consumer Healthcare said Thursday.  Acetaminophen overdoses have been found to be the leading cause of liver damage.

The current dosage of 4,000 mg per day, or eights pills, will be lowered to 3,000 mg per day or six pills.

Acetaminophen, Tylenol's key ingredient, is a common painkiller that is found in many prescription and non-prescription medications.  Doctors said that people have been overdosing because they are not following directions written on labels and mixing medications that contain acetaminophen.

 "Acetaminophen is safe when used as directed," Vice President of Over-the-Counter Medical Affairs Edwin Kuffner, MD said in a statement. "But when too much is taken, it can cause liver damage," he added.

Acetaminophen can cause liver failure and is the leading cause of liver failure in the U.S.  and overdoses kill 400 people a year.

 "People don't think they have to stick to the recommended daily dose," Dr. Michael Wolf, associate division chief of General Internal Medicine at Northwestern University, told ABC News.

Johnson & Johnson faced strong criticism after several of their products were recalled in the past year.

The change will take effect by fall for Extra Strength Tylenol and in 2012 for other Johnson & Johnson products.