Stem Cell 'Wild West' Takes Root Amid Lack of US Regulation

More than 170 clinics across the country are selling experimental stem cell procedures for dozens of diseases and conditions — a mushrooming industry that has flourished despite little evidence of its safety or effectiveness.

The rise of the U.S. stem cell industry illustrates how quickly fringe medicine can outpace government oversight. Over the last five years, academic stem cell researchers have watched in dismay as doctors treat patients with experimental techniques that they say could take years, if not decades, to become sound medicine.

"It's sort of this 21st century cutting-edge technology. But the way it's being implemented at these clinics and how it's regulated is more like the 19th century. It's a Wild West," says Dr. Paul Knoepfler, a stem cell researcher at the University of California at Davis.

Stem cells have long been recognized for their ability to reproduce and regenerate tissue. And while there are high hopes that they will someday be used to treat a range of debilitating diseases, critics say stem cell entrepreneurs have little more than anecdotes to support their offerings.

In 2010 there...