Fact-checking troubling R3 Stem Cell clinic chain

I’ve had concerns about an American unproven clinic firm called R3 Stem Cell for many years. They sell unproven stem cell-related “treatments” via dozens of affiliated locations. I put quotes around treatments because in my view there is no good evidence here for claims of treating numerous serious illnesses.

The goal of today’s post is to shine some light on R3 Stem Cells, how they may have evolved, and to fact-check their offerings.

What I found in researching this post is troubling.

What’s in this article

R3 Stem Cell review | Clinic Offerings | R3 CostCalling R3 StemLetter from the FDA | Claims about FDA regsR3 Stem Cell Tijuana | Take-home messageReferences

Article summary and claim review: R3 Stem Cell is a clinic chain selling expensive and unproven offerings via dozens of affiliates. They claim that their birth-related “therapies” can treat many diverse conditions, but I don’t see solid data to back that up. Claims of treating some serious or life-threatening conditions like Alzheimer’s disease are a red flag.  They received a letter from the FDA in 2019 that raised other issues. Now R3 Stem appears to be selling exosomes and other products in the U.S. Overall, in my view what R3 sells is not clearly safe and effective. Talk to your physician before making a decision about going to a stem cell clinic.

Map of R3 stem cell clinic locations
Map of R3 Stem Cell clinic locations from their website. Is what they are selling in the U.S. safe, effective, and FDA compliant?

A brief review of R3 Stem Cell

David Greene, leader of R3 Stem Cell in promotional material.

I’ve been a professor at UC Davis School of Medicine for almost 16 years studying stem cells and cancer. For more than a dozen of those years I’ve been doing this blog, The Niche.

During the years of writing here, I’ve come across specific unproven clinic firms that in my opinion raise significant issues. R3 Stem Cell fits in that category.

Why am I so concerned with R3?

There are several reasons.

For instance, last summer I wrote about how R3 was one of several clinic firms apparently doing intranasal stem cell procedures on patients. That strikes me as very risky. Some material could inadvertently end up in the brain.

Also, a recent article by Caroline Chen in the New Yorker summarized other key issues.

I was struck in Chen’s article by the description of R3 leader David Greene’s past track record when he was active as a physician including this passage:

“Four more of Greene’s patients died in that two-year period. Others suffered from infections, meningitis, excessive bleeding, and permanent injuries, such as a dropped foot. Alarmed by the “sheer volume of cases” and Greene’s “continued insistence that he made no mistakes in the care of his patients,” the Arizona Medical Board revoked his license in 2009.”

Now his firm R3 Stem Cell sells unproven stem cell-related “therapies” and other offerings through a large network of affiliate clinics.

The FDA sent R3 an untitled letter in 2019 that pointed out potential issues. More on that in a minute.

At one time, according to Chen, R3 Stem Cell was getting materials from Utah Cord Bank, a firm that itself got an FDA letter last year, a more serious one. Last year’s FDA warning letter described Utah Cord Bank’s products as appearing to be unapproved drugs.

Maybe R3 Stem has a different supplier of materials now for U.S. offerings?

R3 Stem Cell clinic offerings

Overall, R3 Stem Cell markets unproven amniotic and umbilical cord materials for many health conditions.

They also have Clinicaltrials.gov listings, but these don’t seem to be traditional clinical studies. For example, to be involved it appears you have to pay thousands of dollars. Also, the studies aren’t designed to produce solid data in my view.

One of their Clinicaltrials.gov listings includes 17 diverse medical conditions and mentions 5,000 participants. How does that make sense? Is this is more about customer recruitment? A website I trust called Science-Based Medicine has written about R3 Stem and is very skeptical. For instance, about that trial including the long list of medical conditions, they wrote:

“This is basically a useless trial, with so many conditions and outcomes that its purpose can only be to allow these clinics to use stem cell treatments for whatever the heck they want to.”

Then there’s the question of biomedical rationale here.

Why would birth-related materials supposedly be able to treat so many diverse medical conditions? To me as a stem cell biologist that just doesn’t make sense. Sure, there are interesting cells in amniotic and umbilical cord tissue. However, you have to do clinical research to prove such cells do something both specific and useful in a consistent way. And that they are safe.

R3 Stem Cell cost: $1,000-$8,000

From what I could gather, R3’s supposed treatments cost a few thousand dollars a pop. A new PR from the firm on May 31, mentioned an exosome therapy for $3,950 available outside the U.S.

It seems that stem cells in Mexico cost about $2,950 at R3.

A general page on cost on the R3 website itself quotes a range of $1,000-$8,000 for treatments.

What do they sell exactly? It was hard for me to be entirely sure.

Calling R3 Stem Cell

Could R3 now be offering something related to stem cells but not actual cells in the U.S.?

I called a few of their location phone numbers to try to find out. I got through to a person at the phone number listed on their stem cells Los Angeles location website. The representative told me that they have 35 locations in the U.S. In my mind a big network means amplified risks to customers.

The phone rep also mentioned a 90% success rate and “no risk”, which are big, testable claims. Where are the data? I’m not aware of any stem cell-related treatment in the world having a 90% success rate or having no risk. Sounds too good to be sure to me. More red flags.

As I talked more with the R3 phone rep, I got a clearer sense of things. At present, he said that they are offering umbilical cord cells outside the U.S. such as at the R3 Tijuana location. The rep continued that they sell various products like exosomes,  PRP, and Wharton’s jelly at the clinics in the U.S.

Yet the FDA has defined exosomes as drugs generally requiring the agency’s pre-approval before being sold to patients. I’ve never seen any indication that R3 has FDA approval to market exosomes. If I’m wrong, hopefully the clinic firm will let me know. I believe Wharton’s jelly is often going to be a drug as well.

I asked the California location R3 rep if they sold cell therapy for Alzheimer’s disease and he said they do. That’s another red flag to me. There is no good evidence that cell therapy including exosomes can help people with Alzheimer’s disease. No one should be selling that today.

Letter from FDA and possible safety concerns

I mentioned that R3 Stem Cell itself received that cautionary 2019 untitled letter from the FDA about their offerings (along with a heads up to its U.S. affiliates). An important part of the FDA letter was a statement that the offerings seem to be unapproved drugs. From the untitled FDA letter (emphasis mine):

“Based on a review of your website, it appears that R3 Stem Cell, LLC does not qualify for any exception in 21 CFR 1271.15 and the stem cell therapies offered by R3 Stem Cell, LLC are intended for nonhomologous uses and would be regulated as drugs as defined in section 201(g) of the FD&C Act [21 U.S.C. 321(g)] and biological products as defined in section 351(i) of the PHS Act [42 U.S.C. 262(i)].”

Also, the FDA letter raised possible safety concerns of the R3 offerings:

“We note that your products are intended to treat a variety of serious or life-threatening diseases or conditions. Such unapproved uses raise potential significant safety concerns. Additionally, because the products are administered by various higher risk routes of administration, including IV, their use, if contaminated could cause a range of adverse events”

I’m guessing this letter led to some changes as to how R3 functions in the U.S.

Inaccurate claims about FDA rules?

When I recently visited various R3 Stem Cell websites it was interesting to read their take on FDA regulations on birth-related materials. Their interpretation conflicts in some important ways with my understanding of the regs. See the screenshot from the R3 website below.

R3 Stem Cell FDA
R3 Stem Cell’s take on FDA regs such as how their products would be classified and regulated doesn’t seem entirely accurate in my view.

It seems to me that they are claiming that their offerings from amniotic material and umbilical cords are not regulated as drugs but rather biologics. Actually, any given product could in theory be both a biologic and a drug. In fact, the FDA said in that past letter to R3 Stem Cell that some of their product seems to be both a biologic and a drug. At least that’s my reading of the letter. It’s in the first passage I quoted from the 2019 letter above.

Also, from the FDA page on exosomes (emphasis mine):

“As a general matter, exosomes used to treat diseases and conditions in humans are regulated as drugs and biological products under the Public Health Service Act and the Federal Food Drug and Cosmetic Act and are subject to premarket review and approval requirements.”

Further, in contrast to the statement on the R3 website, in many cases biologics are going to need approval, and applications can be denied. For instance, an application (like a BLA) for introducing a biologic drug can potentially be rejected by the agency.

R3 Stem Cell California
What exactly is R3 Stem Cell selling in California? Note that I’m not aware of good evidence, as claimed on their website, that amniotic cells can become all those diverse cell types. Screenshot from an R3 website. 


Review of R3 Stem Cell Tijuana and Pakistan claims

An R3 California website (see screenshot above) has a button to “Request an appointment for treatment with stem cell therapy or PRP!” Does the “therapy” in this case mean exosomes and not actual cells? Something else?

What’s going on at their international locations?

R3 has opened several international clinic locations including Tijuana and in Pakistan. Countries such as Mexico and Pakistan have different and usually weaker regulations on the uses of stem cells and similar materials.

The R3 Stem Cell Tijuana clinic has a long list of conditions they can supposedly treat. These include both kinds of diabetes, COPD, heart and kidney disease, Parkinson’s, Alzheimer’s, and much more.

In my view, there is no good evidence for any of that.

I also saw some indication of possible locations in India and the Philippines.

The R3 Stem Cell Pakistan clinic has been making some bold and in my opinion unsupported claims on Twitter about what they can do. See the tweet above, for instance. It has an inaccurate claim about the idea of stem cell therapy for autism. They say it’s already proven, which it isn’t.


Note that I’m not a physician and cannot give medical advice. However, as a stem cell biologist who has been doing research on clinics for more than a decade I see R3 Stem Cell as unlikely to live up to its marketing and claims. The data just aren’t there.

As I’ve discussed in this post, there are numerous red flags too and I have potential safety concerns about R3.

Overall, I just don’t see good evidence to justify the risks and financial costs of what R3 Stem Cell is marketing.


5 thoughts on “Fact-checking troubling R3 Stem Cell clinic chain”

    1. @Neil,
      Thanks for the link. However, we can’t more broad assumptions about clinical uses of MSCs or even a sub-class like cord MSCs.

      Every manufacturer uses different methods. There are also different donors, facilities, reagents such as enzymes, etc.

      Some places amplify the cells in the lab first, which is a big variable.

      Just focusing on infection prevention, some manufacturers do a fantastic job at maintaining cell quality and preventing contamination of products by things like E. coli. Other places, not so much. Some of the GMP violations in FDA warning letters over the years regarding MSC preparations are really concerning.

  1. Rafael M. Valdez, PhD

    Great work! God bless you. Please include me in your next commentaries regarding R3 Stem Cell Therapy. Its now being offered in the Philippines.

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