Embryonic stem cell research has been grabbing headlines since President Obama decided to allow federally funded research last week.
Some doctors overseas claim they have already made amazing steps forward, but doctors in the United States warn patients to beware of possibly life-threatening side effects.
One controversial treatment does not use embryonic stem cells, but instead "adult" stem cells from umbilical cord blood or tissues that were donated after a miscarriage.
It's a treatment that is not done in the United States, but one that Jennifer Blankenship said changed her life when she had the procedure done in Costa Rica.
Blankenship has multiple sclerosis, and for the last two years she's had trouble speaking and was partially paralyzed. But she said an injection of stem cells into her spine changed everything.
"As soon as I had an injection, I was speaking normally," Blankenship said. "I started wiggling my toes, lifting my hands over my head, which I hadn't done in years."
When Terry White of Bridge Health International, a medical tourism company that helps patients find treatments abroad, explains it, it sounds simple.
"Those stem cells get around those nerves and start to rebuild the coating around those nerves," White said.
But doctors in the United States, where cord blood stem cells have only been used to treat blood-related diseases such as leukemia, are skeptical of the results.
"People have heard about stem cells. They believe they can just inject stem cells and wave them around and get miraculous cures," said Dr. Jack Kessler, a stem cell specialist at Northwestern University. "But it's going to be years before we have any kinds of cures for MS, Parkinson's or diabetes."
Last month fetal stem cell injections into the brain of an Israeli boy caused a tumor in his brain.
"Patients, please beware," Dr. John Gearhart, a stem cell scientist at the University of Pennsylvania who wasn't involved in the boy's care, told The Associated Press.
"Cells are not drugs. They can misbehave in so many different ways. It just is going to take a good deal of time" to prove how best to pursue the potential therapy, Gearhart said.
More Americans Seeking Overseas Treatment
That skepticism has not stopped many medical travelers from seeking overseas procedures.
According to the Bridge Health International Web site, the company connects patients and "high-quality medical care that offers immediate service and access to procedures that may not be available locally" including several different stem cell therapies.
Researchers told "Good Morning America" there has been an "uptick" in foreign clinics offering so-called stem cell miracle cures and they are not cheap. Many charge between $20,000 and $60,000 for procedures like the one Blankenship had.
"There are clinics now being set up all over the world," Dr. George Daley, an associate professor at Harvard Medical School, said last year. "There is a clinic in Bermuda, there is a clinic in Barbados, there are clinics in Eastern Europe."
According to Daley, these clinics are created in the wave of hype around the promise of stem cells.
"The fact is that there are many desperate patients out there who don't want to wait for the slow process of medical research and medical advancement," he said. "To say that cord blood stem cells are ready for prime time, ready for interventions in neurodiseases or heart diseases, or anything outside the blood, is really the height of speculation."