Stem cell therapy is legal in the US in a limited way: a few products are FDA-approved, but most stem cell injections for joints, pain, and anti-aging are not. Clinics can still offer many of these procedures because of a narrow tissue rule and slow enforcement. That gap between “for sale” and “approved” is the single most important thing to understand before you pay.
This hub gives you the plain-English version of the law. It explains what the U.S. Food and Drug Administration has actually cleared, what clinics sell under an exemption, and what happens when the FDA pushes back.
The law in plain English
You can legally receive some stem cell procedures in the US, but “legal to offer” is not the same as “proven or approved.” Three tiers explain almost every situation you will meet.
Tier 1: FDA-approved products. These have passed clinical trials and carry an approved use. They cover blood and immune disorders, not orthopedic pain.
Tier 2: Products sold under the 361 tissue exemption. These skip pre-market approval if they meet strict rules. The FDA says most joint and systemic uses do not qualify.
Tier 3: Unapproved products. These are sold anyway. The FDA can issue warning letters, seek injunctions, or refer for prosecution, but it does not catch every clinic.
Most clinics selling knee, hip, or anti-aging injections sit in Tier 2 or Tier 3. That is the core of the confusion.
What the FDA has approved
The FDA has approved blood-forming stem cell transplants and a small number of cell products. Hematopoietic stem cell transplants, using cells from bone marrow or cord blood, are the oldest approved use. They treat leukemia, lymphoma, sickle cell disease, and other blood and immune conditions.
The agency has also approved a few named products. Ryoncil (remestemcel-L), cleared in late 2024, treats steroid-refractory graft-versus-host disease in children. In June 2026, the FDA approved Tregzi, a cell therapy used with matched-donor transplants. Cord-blood products for blood reconstitution are approved too.
None of these are for knee arthritis, back pain, or general “anti-aging.” Our FDA status guide lists the full approved set and what each one is for.
The 361 exemption in plain English
The 361 exemption lets a clinic skip FDA approval only if the cells meet four strict tests. The rule comes from Section 361 of the Public Health Service Act and the tissue regulations in 21 CFR Part 1271. To qualify, the product must be all of the following.
- Minimally manipulated. The processing must not change the cells’ basic biological features.
- Homologous use only. The cells must do the same job they did in the body they came from.
- Not combined with another drug or device, with narrow exceptions.
- No systemic effect that depends on the cells being alive, except for certain uses.
Most orthopedic and IV stem cell products fail at least one test. Culturing cells to grow more of them counts as more than minimal manipulation. Injecting fat or cord cells into a joint to fix cartilage is often not homologous use. When a product fails these tests, the FDA treats it as an unapproved drug.
Enforcement: what actually happens
Enforcement exists but is uneven, so an unapproved product can stay on the market for years. The FDA ended its regenerative-medicine grace period in May 2021. Since 2017 it has sent roughly 400 letters to clinics and manufacturers and issued dozens of formal warning and untitled letters.
The agency has also won court action against some larger operators. Still, the FDA cannot inspect every clinic, and a warning letter is not an instant shutdown. Some clinics change wording, some keep selling, and some close only after a patient is harmed.
For you, the takeaway is direct. A clinic operating today does not mean its product is legal or approved. It may mean it has not been reviewed yet.
Legal to sell vs safe to buy
A treatment can be legal to sell and still be a poor choice, so separate the two questions. Legality tells you whether the FDA has cleared or tolerated a product. It says nothing about whether the therapy is proven, or whether one specific clinic is competent.
That is why this hub pairs with our safety work. The most useful thing you can do is check a clinic against known red flags before you pay a deposit. Our guide on how to vet a clinic turns the law above into concrete questions to ask.
Going abroad: still a legal choice
Traveling overseas for an unapproved stem cell therapy is legal for US patients. Nothing in US law stops you from getting a treatment abroad that the FDA has not approved. Many patients go to Mexico or other countries for lower prices and faster access.
The trade is oversight. Foreign regulators such as Mexico’s COFEPRIS set their own rules, and quality varies by clinic, not just by country. Our comparison of the best countries for stem cell therapy weighs regulation, cost, and access, without making any claim about whether the treatments work.
The bottom line on US legality
Is stem cell therapy legal in the US? A few approved products are fully legal, but most joint, pain, and anti-aging injections are unapproved and sold under an exemption the FDA disputes. Legal availability is not proof of approval, safety, or benefit. Learn what the FDA has cleared, understand the 361 exemption, and vet any clinic hard before you spend a dollar. An informed decision starts with the real legal status, not the marketing.
Frequently asked questions
Is stem cell therapy legal in the United States?
Offering some stem cell procedures is legal, but most joint, pain, and anti-aging stem cell products are not FDA-approved. A handful of blood and immune therapies are approved. Everything else is sold either inside a narrow tissue exemption or as an unapproved product the FDA can act against.
Can a US clinic legally inject stem cells into my knee?
It depends on the product. A same-day procedure using your own minimally processed tissue may fall under a tissue rule, but many cultured or donor-cell knee injections are unapproved drugs. The FDA has sent hundreds of letters to clinics marketing these for orthopedic use.
What stem cell treatments has the FDA actually approved?
The FDA has approved blood-forming stem cell transplants and a small set of cell products such as Ryoncil for pediatric graft-versus-host disease and cord-blood products. See our FDA status guide for the full approved list.
Is it legal to go to Mexico for stem cell therapy?
Yes. You can legally travel abroad for stem cell therapy that is not approved in the US. Mexico regulates clinics through COFEPRIS, but oversight and quality vary. See our Mexico guide before you book.
Why do so many clinics operate if the treatments are not approved?
Many clinics rely on a tissue exemption meant for minimally manipulated cells used for the same purpose they came from. The FDA says most joint and systemic uses fall outside that exemption, but enforcement is limited and slow, so clinics keep operating.
Medical disclaimer. Medical Frontier is an independent educational resource. This page is for general information only and is not medical advice, diagnosis, or treatment, and does not create a doctor–patient relationship. Most regenerative therapies discussed here are not FDA-approved for the uses described and may be offered under limited exemptions or in clinical trials only. Always consult a licensed physician before making any treatment decision.