Stem cells explained in one line: they’re real science with a short list of proven treatments, some exciting early results, and plenty of hype to sort through. Our new five-minute video answers the 8 questions people search most, and this article is the text version, with sources for every claim.
Video chapters
- 0:00 Intro
- 0:19 What are stem cells?
- 0:44 What are the types of stem cells?
- 1:27 What can stem cells treat today?
- 2:13 What’s coming next?
- 2:55 Are stem cell clinics legit?
- 3:37 How much do stem cell treatments cost?
- 4:16 Should I bank my baby’s cord blood?
- 4:38 How do I spot a red flag?
- 5:02 Wrap up
Every one of us started as a single cell, and that one cell built everything: your heart, your brain, your blood. The cells that make this possible are stem cells, one of the most searched, most hyped, and most misunderstood topics in medicine. Here are straight answers.
1. What Are Stem Cells? Stem Cells Explained Simply
Most cells in your body have one job. A skin cell stays a skin cell. Stem cells are different in two ways. First, they can copy themselves again and again, which is called self-renewal. Second, they can turn into specialized cells like blood, bone, or nerve, which is called differentiation.
Think of them as the body’s raw material and its repair crew. For a deeper primer, see our guide What Are Stem Cells? A Simple Guide.
2. What Are the Types of Stem Cells?
There are three main types you’ll hear about:
- Embryonic stem cells come from embryos only a few days old, usually donated after IVF. They’re pluripotent, meaning they can become almost any cell type in the body.
- Adult (tissue) stem cells live in places like your bone marrow and are more limited. Blood-forming stem cells, for example, make blood and immune cells.
- Induced pluripotent stem (iPS) cells are ordinary adult cells reprogrammed into an embryonic-like state. In 2006, Shinya Yamanaka’s lab showed this could be done with just four genes, a discovery that won a Nobel Prize in 2012.
If embryonic cells are blank clay, adult stem cells are clay that’s already partly shaped, and iPS cells are finished pottery softened back into clay.
3. What Can Stem Cells Treat Today?
The proven workhorse is the blood stem cell transplant, often called a bone marrow transplant. Doctors have used it for decades to treat leukemia, lymphoma, and other blood and immune disorders.
Newer approvals build on it. In December 2023, the FDA approved Casgevy, which gene-edits a patient’s own blood stem cells to treat sickle cell disease. In December 2024, it approved Ryoncil, the first mesenchymal stromal cell therapy in the US, for children with graft-versus-host disease. Beyond a short list like this, most stem cell uses are still being tested.
4. What’s Coming Next?
Two results published in 2025 turned heads. In type 1 diabetes, a trial of lab-grown islet cells found that 10 of 12 full-dose participants no longer needed insulin at one year. In Parkinson’s disease, two early trials published in Nature in 2025 transplanted dopamine-making cells grown from stem cells. The grafts survived, with no serious safety problems linked to the cells in those small groups.
The fine print matters. These were small, early studies, and patients needed immune-suppressing drugs, which carry their own risks. Bigger trials are underway. (For the latest on this front, read Japan’s first approved iPS cell transplant for Parkinson’s.) It’s real progress, built on real data, but it’s a seedling, not a harvest.
5. Are Stem Cell Clinics Legit?
This is the question many people are really asking. A 2016 study found 351 US businesses marketing unproven stem cell treatments at 570 clinics, advertising them for everything from arthritis to autism. Most of these treatments are not FDA approved, and the FDA has warned consumers about them.
The risks are real. In 2017, doctors reported in the New England Journal of Medicine on three women who lost most or all of their vision after a clinic injected cells from their own fat into their eyes for macular degeneration.
6. How Much Do Stem Cell Treatments Cost?
It depends on what you’re buying. Approved transplants for blood cancers are major hospital procedures, but they’re usually covered by insurance. Unproven clinic treatments usually are not.
A survey of US sports medicine practices found stem cell knee injections averaged about $2,700, ranging from $300 to $12,000. Clinics marketing treatments for other conditions can charge tens of thousands, paid out of pocket. Do they work for knees? The evidence is mixed, and large placebo-controlled trials are still running.
7. Should I Bank My Baby’s Cord Blood?
Cord blood is rich in blood-forming stem cells, and donated cord blood is used in transplants every year. The American Academy of Pediatrics encourages donating to a public bank. It recommends private banking mainly when a family member has a condition a transplant could treat.
8. How Do I Spot a Stem Cell Clinic Red Flag?
Be wary of clinics that:
- claim one treatment fixes many unrelated diseases,
- rely on testimonials instead of published data, or
- charge you to join a “study.”
Ask for an FDA approval or a ClinicalTrials.gov registration number. Legitimate trials are registered, and you can look them up yourself. Our stem cell clinic red flags checklist walks through more warning signs.
The Bottom Line
Stem cells are real science, with real treatments and real breakthroughs on the way. The trick is knowing which is which.
Sources
- Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell, 2006. https://doi.org/10.1016/j.cell.2006.07.024
- FDA approval of Casgevy for sickle cell disease, December 8, 2023.
- FDA approval of Ryoncil (remestemcel-L) for pediatric steroid-refractory acute graft-versus-host disease, December 18, 2024.
- Reichman TW et al. Stem cell-derived, fully differentiated islets for type 1 diabetes. NEJM, 2025. https://doi.org/10.1056/NEJMoa2506549
- Tabar V et al. Phase I trial of hES cell-derived dopaminergic neurons for Parkinson’s disease. Nature, 2025. https://doi.org/10.1038/s41586-025-08845-y
- Sawamoto N et al. Phase I/II trial of iPS-cell-derived dopaminergic cells for Parkinson’s disease. Nature, 2025. https://doi.org/10.1038/s41586-025-08700-0
- Turner L, Knoepfler P. Selling stem cells in the USA: assessing the direct-to-consumer industry. Cell Stem Cell, 2016. https://doi.org/10.1016/j.stem.2016.06.007
- Kuriyan AE et al. Vision loss after intravitreal injection of autologous “stem cells” for AMD. NEJM, 2017. https://doi.org/10.1056/NEJMoa1609583
- Momaya AM et al. The cost variability of orthobiologics. Sports Health, 2019. https://doi.org/10.1177/1941738119880256
- American Academy of Pediatrics. Cord blood banking for potential future transplantation. Pediatrics, 2017.
This article and video are for education only and are not medical advice. Talk to your doctor before trying any treatment.
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