By Alvin Philipose, DC (Ret.), Clinic Director · Part of our guide to Stem Cells & Exosomes in Oklahoma
When a clinic says “stem cells,” ask which ones. The term covers cells with very different abilities, sources, research records and legal status. Here is how they break down.
Hematopoietic (blood-forming) stem cells
Found in bone marrow, mobilized peripheral blood and umbilical cord blood, these cells rebuild the blood and immune system. They are the basis of bone marrow and cord blood transplantation, the most established stem cell therapy in medicine. Several cord blood products are FDA-licensed for transplantation in disorders of the blood-forming system. See the approved list.
Mesenchymal stromal cells (MSCs)
Often called mesenchymal “stem” cells, MSCs are found in bone marrow, fat, umbilical cord tissue (Wharton’s jelly) and other tissues. Much of their effect in studies seems to come from the signals they release, including exosomes, rather than from becoming new tissue. One MSC product, Ryoncil (remestemcel-L), was FDA-approved in December 2024 for steroid-refractory acute graft-versus-host disease in children. Every other MSC use is investigational.
- Bone marrow MSCs: the most studied source.
- Adipose-derived cells: harvested by liposuction; “stromal vascular fraction” (SVF) made by enzymatic digestion has been held by a federal appeals court to be a drug requiring FDA approval (United States v. US Stem Cell Clinic, 11th Cir. 2021).
- Umbilical cord / Wharton’s jelly: donor birth tissue. The FDA has repeatedly stated that these products, when marketed for orthopedic or systemic conditions, are drugs and biologics.
Induced pluripotent stem cells (iPSCs)
Adult cells reprogrammed in the lab to behave like embryonic cells. They can become almost any cell type and are being developed into specific therapies, such as dopamine neurons and retinal cells, through formal clinical trials.
Embryonic stem cells
Pluripotent cells from early-stage embryos. Use is limited to research and regulated clinical trials.
Tissue-specific progenitor cells
Cells committed to one tissue, such as cartilage cells. MACI, an FDA-approved product, uses a patient’s own cultured cartilage cells to repair knee cartilage defects.
Autologous vs. allogeneic
| Autologous (your own) | Allogeneic (donor) | |
|---|---|---|
| Immune rejection | Not a concern | Possible; depends on cell type |
| Disease transmission | Not a donor concern | Requires donor screening and testing |
| Same-procedure exception | May apply if removed and returned in one procedure without more than minimal processing | Does not apply |
| Typical legal lane | Depends on manipulation and use | Usually a drug/biologic unless all “361” criteria are met |
What about “VSELs” and other claims?
Very small embryonic-like stem cells (VSELs) are a research hypothesis that remains debated in the scientific literature. Treat any claim that a commercial product contains “millions of live stem cells” with skepticism and ask for independent lab verification.
Where to go from here
If you’re weighing a stem cell option, start with the regulatory status and the pathway. Read Legal Pathways to Investigational Treatment and How to Choose a Stem Cell Clinic, or call (405) 848-7246 for a free 15-minute discovery call.
Educational information only, not medical advice. Unless identified as FDA-approved for a specific use, stem cell products are investigational.