Stem cell therapy is generally considered safe when using adult stem cells collected from the patient, which minimizes the risk of an unwanted reaction. However, like any medical procedure, it carries some risks, such as infection or administration site reactions. The safety of stem cell therapy also depends on the specific type of cells used, whether they are cultured, and if they are mixed with other substances. Patients must seek treatment from reputable clinics that adhere to FDA guidelines and have a track record of safely conducting such procedures.