Be cautious because there are companies (at least one I've read of) marketing stem cell therapies that have no scientific basis. There's no reason to think that what they are doing will work. This company has been charging something like ten thousand dollars for a treatment and moving from country to country as they have been shut down.
I understand the need for treatments now, but it's sad for a company to take so much money from someone who is very sick by taking advantage of their illness.
What has been offered is a transfusion with hematopoietic stem cells, which means blood stem cells. These are cells that have already "decided" to be blood cells, but still have the potential to become different kinds of blood cells, such as red blood cells, white blood cells.
There are two or three major, major problems with what this company has been offering. One is that they are saying the blood stem cells can cure non-blood related diseases, like diseases that have to do with nerves. The cells they inject have already decided to be blood cells. This is a problem.
The second problem is that, for the hematopoietic stem cells to graft, meaning to take hold and grow in a recipient, the patient would have to go through a bone marrow transplant, meaning severe treatment to kill their own bone marrow. Otherwise the immune system will kill off the donor stem cells.
The third problem is that, even if there were some stem cells in the blood that could become nerve or other tissue, if those are just injected, they run the risk of starting other cancers. This point is a little bit tricky, and that's because there is a lot of active research going on in this area. In the idea of using stem cells for therapy, they need to have some instructions (meaning molecular signals) before being injected, otherwise they form tumors. This is not ready for patients yet.
The other very serious risk is that anyone who signed up for such a treatment is putting their trust in a company that has been put out of business for doing bad science, in the case I'm thinking of. There's no way to know whether they have screened their donors for HIV and other blood borne infectious diseases.
People are working very hard to try to come up with better treatments. I know it's not a good answer for anyone who is sick now. Research budgets are being cut at the federal level, and a lot of good labs are having to slow their work or shut down. If you want more progress faster, write your congress person and tell them you support more NIH funding. We're doing our best with your money.