Both approved and unapproved stem cell therapies have side effects. The Cancer.org website goes into detail about the potential negative effects of blood stem cell transplants. Patients thinking about receiving an unapproved stem cell therapy should be aware that there are significant risks associated with such procedures, and that these risks may not be adequately managed by a trained care team. It has been proven to cause severe illness and, in some cases, blindness when even a person's own tissue is injected into a different body part.

There is a financial risk associated with the treatments provided by stem cell clinics. People seeking therapy must pay significant out-of-pocket costs because these operations are typically not covered by insurance, and there is no assurance that their health will improve as a result.