Stem Cell Therapy: What Science Currently Supports and What It Doesn't

One Treatment Is FDA-Approved; Most Clinics Offering Stem Cell Therapies Are Not

Hematopoietic stem cell transplantation (HSCT) — commonly called a bone marrow transplant — has been performed since 1968 and remains the only well-established stem cell therapy with decades of safety and efficacy data. As of 2023, the FDA had approved a small but growing number of additional cell and gene therapies for specific conditions. What has also grown exponentially is an industry of clinics offering unproven stem cell injections for arthritis, autism, ALS, spinal cord injury, and dozens of other conditions — at prices ranging from $5,000 to over $50,000 per treatment — with little or no clinical trial evidence supporting them.

Stem cells are cells capable of self-renewal and differentiation into specialized cell types. Different classes of stem cells have different biological properties, clinical histories, and ethical considerations. Understanding these distinctions matters when evaluating specific claims about treatments.

Types of Stem Cells and Their Clinical Status

The FDA's approval of Casgevy (exagamglogene autotemcel) in December 2023 — the first CRISPR-based gene editing therapy, used with stem cell transplant for sickle cell disease — marked a significant milestone. It is approved for patients 12 and older with sickle cell disease causing recurrent vaso-occlusive crises.

Where Evidence Is Strong

Bone marrow transplantation is the clearest success story. The evidence is clear and long-standing.

• Leukemia and lymphoma: Allogeneic (donor) HSCT can produce durable remissions and cure in subsets of patients with acute myeloid leukemia, acute lymphoblastic leukemia, and certain lymphomas — particularly when other treatments have failed
• Sickle cell disease: Allogeneic HSCT from matched sibling donors has achieved functional cure in 85–95% of pediatric patients in published series. The gene therapy approach (Casgevy) avoids the need for a matched donor
• Beta-thalassemia: Similar curative potential via HSCT or gene therapy (Zynteglo, approved 2022)
• CAR-T therapies: FDA-approved CAR-T products including Kymriah (tisagenlecleucel), Yescarta, and Carvykti have achieved complete response rates of 30–85% in heavily pre-treated patients with certain blood cancers, with some long-term remissions

Where Evidence Is Weak or Absent

The conditions most often targeted by unregulated stem cell clinics have limited or no supporting clinical trial evidence. This is not to say the research is uninteresting — active trials exist for many of these conditions — but trials are different from proven treatments.

• Osteoarthritis: Small studies using mesenchymal stem cell injections show modest pain relief in some trials, but results are inconsistent and long-term safety data is lacking. No MSC product is FDA-approved for arthritis as of 2024
• ALS and Parkinson's disease: Multiple trials are underway, but no stem cell therapy has demonstrated significant disease modification in phase 3 trials for either condition
• Autism spectrum disorder: Cord blood infusion trials at Duke University showed no significant improvement over placebo in randomized controlled trials published in 2020
• Spinal cord injury: Early-phase trials show some safety signals but no established efficacy for neurological recovery

The Problem of Unregulated Clinics

The FDA, in cooperation with the Federal Trade Commission, has taken action against numerous stem cell clinics operating outside the regulatory framework. A 2019 JAMA Internal Medicine study identified 716 clinics across the U.S. marketing unapproved stem cell interventions. Three patients were blinded after receiving contaminated stem cell injections marketed for macular degeneration at a Florida clinic — a case documented in the New England Journal of Medicine in 2017.

• The FDA considers most stem cell products to be biological drugs requiring approved clinical trials or an Investigational New Drug (IND) application before use in patients outside of established treatments
• Patients seeking stem cell treatments at unlicensed clinics bear all financial and health risks; no insurance covers unapproved procedures, and adverse events may not be compensable
• ClinicalTrials.gov lists all registered U.S. trials; legitimate experimental treatments are conducted under IRB oversight and typically at no cost to participants

This article is for informational purposes only. Consult a qualified healthcare professional before making medical decisions.