Stem Cell Therapy: Established Uses, Approved Products, Risks and How to Check a Treatment

What stem cell therapy is

Stem cell therapy is a broad term. It covers any treatment that puts stem cells, or cells and products made from them, into a patient to restore tissue or immune function. Stem cells can renew themselves and can develop into more specialized cells. Patient materials from the International Society for Stem Cell Research (ISSCR) describe four main types: embryonic stem cells, induced pluripotent stem (iPS) cells, tissue-specific (adult) stem cells, and mesenchymal stem or stromal cells (MSCs).[4] Each type behaves differently, so evidence for one type does not carry over to another. The same is true for different diseases and different ways of giving the cells.

The ISSCR says proven stem cell treatments cover only a narrow range of conditions. These are mainly blood and immune system disorders treated with blood stem cell transplants, which have been used for more than 50 years. Stem cells are also used for tissue regeneration in some skin and cornea grafts. The ISSCR describes other stem cell treatments as still experimental, meaning they have not yet been shown to be safe or to work.[4]

The established use: hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT), often called a bone marrow or blood stem cell transplant, replaces a patient's blood-forming system. It can use the patient's own cells (autologous) or cells from a donor (allogeneic).[5] The Worldwide Network for Blood and Marrow Transplantation counted 1,298,897 HSCTs worldwide from 1957 to 2016. The yearly number rose from 46,563 in 2006 to 82,718 in 2016, and the data came from 1,662 transplant teams in 86 countries.[3] In 2016, 53.5% of transplants were autologous and 46.5% were allogeneic.[3]

Main indications

In 2016, lymphoproliferative disorders (such as lymphoma and myeloma) accounted for 53.0% of HSCTs, leukemias for 35.7%, non-malignant disorders for 7.3% and solid tumors for 3.6%.[3] The same analysis found that transplants from related donors became more common than those from unrelated donors starting in 2014. This change was mainly driven by the growing use of haploidentical (half-matched) family donors.[3]

Graft-versus-host disease and other transplant risks

Graft-versus-host disease (GVHD) is a potentially life-threatening complication of allogeneic transplantation. It happens when donor cells attack the recipient's tissues. It does not occur when patients receive their own cells.[5] MedlinePlus puts the chance of GVHD at about 35–45% when donor and recipient are related and about 60–80% when they are not.[5] Acute GVHD usually affects the skin, liver and intestines. Chronic GVHD can also affect the eyes, mouth, lungs and joints.[5]

Approved stem cell products

Outside HSCT, regulators have approved only a small number of stem cell products, each for a specific use. The FDA lists its approved cellular and gene therapy products in a public register, which was last updated on 17 September 2026.[2]

Ryoncil's approval was based on a single-arm study in 54 children. At day 28, the overall response rate was 70%, including a complete response rate of 30%.[8] A 2023 review counted 12 MSC therapies approved by regulators worldwide as of April 2023, five of them in South Korea.[6] Approval can also be reversed. Alofisel's EU marketing authorisation was withdrawn in December 2024 at the request of its marketing authorisation holder.[7]

Investigational and unapproved uses

The FDA warns about stem cells, stromal vascular fraction, cord blood, amniotic fluid, Wharton's jelly and exosome products sold outside clinical trials. It states that these products are not approved to treat autism, macular degeneration, COVID-19, neurological disorders (including Alzheimer's disease, Parkinson's disease, ALS and multiple sclerosis), heart or lung diseases, or orthopedic conditions.[1] The FDA also notes that listing a trial in a registry, or registering a firm with the FDA, does not mean the product is legally marketed.[1]

Reported harms

Harms the FDA has reported from unapproved products include blindness, tumor formation, infections (including sepsis), neurological events, unwanted immune responses, cells moving to unintended sites, and contamination with pathogens.[1] One published case series described three patients who received paid injections of their own fat-derived "stem cells" into both eyes at a U.S. clinic. Before treatment, their better-eye vision ranged from 20/30 to 20/50. One year later it ranged from 20/200 to no light perception, after retinal detachments and repeated surgery.[10]

How stem cell therapy is regulated

• United States: The FDA regulates stem cell products, keeps a public list of approved products, and asks consumers to report adverse events through MedWatch.[1][2]
• European Union: Stem cell medicines are authorised centrally through the European Medicines Agency, and authorisations can be withdrawn.[7]
• South Korea: Stem cell products are approved by the Ministry of Food and Drug Safety (MFDS). The Act on the Safety of and Support for Advanced Regenerative Medicine and Advanced Biological Products was enacted in 2019, and an amendment took effect in February 2025. It created a category called "advanced regenerative medicine treatment". Under it, designated institutions may offer investigational cell, gene and tissue-engineered therapies to patients with life-threatening or intractable diseases, including rare diseases. A central 25-member committee must approve each treatment plan. Approvals last five years, and patients pay the full cost.[9] The same analysis notes concerns about reviewer conflicts of interest and long-term safety monitoring.[9]

How to evaluate a stem cell treatment offer

The ISSCR suggests that patients check the following before agreeing to treatment:[4]

1. Published preclinical studies that independent experts have reviewed.
2. Approval from an Institutional Review Board or Ethics Review Board.
3. Authorization from a national or regional regulator (for example the FDA, EMA or, in Korea, the MFDS) for the trial or for medical use.
4. A clear written treatment protocol and an informed consent document.
5. A second opinion from an independent, qualified physician.

The ISSCR lists these warning signs: claims based on patient testimonials, one treatment offered for many unrelated diseases, an unclear cell source or procedure, claims that there is no risk, and high or hidden costs for unproven treatments.[4] The FDA invites consumers to contact it before pursuing a regenerative medicine product.[1]

Cost

No verified source was found for a typical price range, so none is given here. Costs vary widely by indication, product and whether treatment is given as standard care, in a clinical trial, or under a special access scheme. Under Korea's advanced regenerative medicine treatment system, patients pay the full cost.[9] The ISSCR lists high or hidden charges for unproven treatments as a warning sign.[4] Patients can ask for a written itemized quote. They can also ask whether the treatment is covered by public insurance, which usually applies only to approved uses.

Limits of current evidence

Evidence is strongest for HSCT in blood cancers and some non-malignant blood disorders.[3][4] Evidence for other approved products applies only to their approved indication, and it may later be reassessed, as the Alofisel withdrawal shows.[7] For most other conditions, controlled clinical trial data remain limited, which is why regulators and professional societies advise patients to confirm a treatment's approval status before taking part.[1][4]