McKINNEY – Two weeks after Tonya Winchester celebrated her high school graduation, an 18-wheeler slammed into her Jeep Cherokee, paralyzing the college-bound teenager from the chest down.

Therapists said she would not improve, and they advised her to work with what she had left.

Instead, she took the advice of fellow patients and searched for a medical miracle half a world away.

In March, she and her family flew to Russia, putting Ms. Winchester's care in the hands of people they had never met at a cost of nearly $30,000. She believes the adult stem cell therapy, which involves injections not approved in the United States, will help heal her spinal cord and improve her mobility. She plans to return in July.

"I was scared, of course, but I'm going to do what I need to do to gain anything," said Ms. Winchester, now 19.

"I had just graduated. I was ready for my independence. I feel like I was robbed completely of everything," she said of the 2005 accident.

Medical tourism is a fast-growing phenomenon in the United States. As health costs skyrocket and 47 million remain uninsured, Americans are finding far cheaper hip replacements in India, bariatric surgery in Singapore and heart surgery in Thailand.

But others, especially spinal cord injury patients like Ms. Winchester, head overseas seeking new or alternative therapies that are often unapproved at home – and unproven – despite the risks.

What they see as a frustrating conservatism that hampers innovation in the United States, many experts view as necessary safeguards.

"I think we always try to err on the side of cautiousness," said Jerry Silver, a researcher at the National Center for Regenerative Medicine in Ohio. Other countries lack oversight as well as proof of efficacy and safety that would be required in the United States, he said.

"They believe you can just use people as guinea pigs," Dr. Silver said. If other countries truly had therapies that were proven to work, experts said, they would be done here. "It's taking advantage of people that are at risk. I think it's just terrible."

But many spinal cord injury patients say alternative medical care abroad has improved their lives.

After he was paralyzed in a Texas Christian University football game more than 30 years ago, Kent Waldrep sought experimental treatment in the Soviet Union. Well-known U.S. medical authorities told him and his supporters before the trip that it was a foolish waste of time.

When he returned, Mr. Waldrep said, doctors who evaluated him said that the results were interesting and "pretty substantial" but that they wouldn't last.

"Of course it not only lasted, but my physical situation is a lot better than it ever was supposed to be," said Mr. Waldrep, 53, who continues to be a proponent of therapy abroad, as long as it is backed by reputable organizations.

"I have more movement. I have feeling all over my body. I had two kids I was never supposed to have," he said. "My quality of life is what other spinal cord [injury patients] should have the opportunity to enjoy. I'm still in a wheelchair, but I've just been able to do so much more than the doctors [said]."

Though research and care today is leagues ahead of what was initially available to Mr. Waldrep, spinal cord injury patients remain frustrated that there are not more clinical trials and treatments available in the United States, he said.

"People search for answers. ... They don't want to hear, 'Nothing is available. Go home and deal with your situation,' " he said.