"Stem cells" is a category. Not a product.
Two clinics can both advertise "MSC therapy" with identical-sounding marketing and have wildly different products in the syringe. From the outside, the websites look similar. The cell counts may even be similar. The marketing language is interchangeable. But what's actually being injected is, in many cases, fundamentally different.
This page exists because patients deserve to know that. It's not a comparison of named clinics. It's a description of the categorical differences that exist across the industry, the differences that determine what your therapy actually consists of, and a practical checklist of questions that surface those differences.
If you only read one article in this section, this is the one.
One label. Six places it diverges.
Each row is a real, measurable axis along which clinics offering the same nominal therapy diverge. The left end is what shows up most often in the industry. The right end is what a serious cGMP program looks like.
Where the cells come from changes everything downstream.
A clinic using autologous bone marrow aspirate is offering a different therapy than a clinic using expanded allogeneic cord-derived cells, even if both are described as "stem cell therapy" on the website.
The source determines the cell age (yours vs. a screened newborn donor's), the cell yield (low millions vs. hundreds of millions), the harvest procedure (a needle in your hip vs. nothing on you at all), and the regulatory framework that governs how the cells are made.
This isn't ambiguous on a clinic's part. They know which they're using. Whether they tell you depends on whether you ask.
"MSC" is itself a population, not a single cell.
Even after you fix the source (say, two clinics both using allogeneic cord-derived MSCs), the cells in the bag are not all identical. Within any MSC preparation, functional subpopulations exist: cells with distinct surface-marker profiles that correlate with different biological behaviors. The ISCT identity panel (CD73+ / CD90+ / CD105+) confirms the cells are MSCs. It does not say which subpopulation of MSC is dominant in the batch.
Two subpopulations are well-characterized in the literature, and both matter for the physician team's protocol design:
Neurotrophic & immunomodulatory bias
- Stronger neurotrophic signaling
- Enhanced immunomodulatory activity
- Relevant for neurologic, autoimmune, and chronic post-inflammatory cases
- Enriched preparations preferred where neural support is the goal
Vascular & pericyte bias
- Pericyte-related behavior at the vascular interface
- Pro-angiogenic profile
- Relevant for ischemic, post-injury, and perfusion-limited tissue environments
- Enriched preparations preferred where vascular support is the goal
Surface markers can be used to identify and enrich for cells whose profile is best suited to the target indication, allowing the physician team to build protocols around populations with the strongest relevant mechanism expression for a given case. This is one of the levers the team can pull that a clinic running a single off-the-shelf "MSC product" cannot.
"Do you characterize subpopulations within your MSC preparations, or release on the basic ISCT panel only? Can you select for a specific subpopulation when the indication calls for it?" Both answers can be legitimate. The first answer reveals a program that thinks of the cell type as part of the protocol; the second reveals a program that uses a single product across indications.
The clinic, or somebody else?
This is the divergence patients almost never ask about, and the one that matters most. There are two fundamentally different operating models in the regenerative medicine industry:
Clinic purchases cells from an outside lab
- Cells arrive in vials from a third-party laboratory
- CofA reflects viability at time of freezing, not at time of injection
- Thawed at the bedside, sometimes warmed in a hand, and injected without anyone checking what the cells look like first
- No visibility into how the cells were made or screened
- Lower capital cost, and lower control
Clinic operates its own laboratory
- Donor screening, isolation, expansion, freezing, all in-house
- Quality control run by the same team treating the patient
- Viability assayed the morning of treatment
- Full traceability from donor to dose
- Higher cost, and the only model that knows what's in the syringe
Model A is much more common, especially in the U.S. and at clinics across Mexico, in Tijuana and Cancún alike. It allows a clinic to offer "stem cell therapy" without the capital investment of running its own laboratory. The cells come from a supplier; the clinic markets, sells, and delivers them. Celva runs Model B: our proprietary cells are manufactured in our own cGMP lab at Hospital Angeles, never bought from an outside supplier.
At Celva, we've seen this dynamic firsthand: there are clinics that have no idea what the cells look like, that are purchasing cells from labs. In practice that can mean a frozen vial thawed in someone's hand at the bedside and drawn straight into a syringe, with no one having looked at the cells since the day they were frozen. They're given a CoA that says this is the viability and these are the counts. But that CoA is at time of freezing. Once cells are actually prepped and given to a patient, after thaw and washing, a lot can have changed. Cells that aren't viable can produce a pro-inflammatory response, the opposite of what's intended.
"Where do your cells come from? Do you operate your own lab, or do you purchase from an outside supplier? If outside, who?" The answer reveals which model the clinic operates under. Both models can produce legitimate clinical work, but they're not the same model, and the variance in what you actually receive is much higher under Model A.
The CofA from the freezer, or the assay from this morning?
Cell viability changes between the moment a vial leaves the manufacturing lab and the moment those cells enter a patient. The freezing process can damage cells. Storage and transport can damage cells. The thaw protocol can kill cells. The wash step can kill cells. Time held in suspension before injection can kill cells.
What the CofA doesn't measure
Each dot is a discrete event between manufacturing and infusion. Viability decays at each step. The CofA captures only the first point. The morning-of assay captures the last.
The CofA viability number, generated at time of freezing, captures none of this. A vial that left the lab at 98% viable can arrive at a patient at 70% viable if anything in the chain went wrong, and the patient and the treating clinic may have no way of knowing.
A lab that tests viability the morning of treatment knows what it's actually administering. A clinic that doesn't test on the day of treatment is administering an unknown.
This is one of the cleanest signals available about which kind of program you're working with. It's not a hidden detail. A clinic either tests viability on the day of treatment or it doesn't, and the answer is binary.
Who's actually evaluating you?
"Physician-led" is on most stem cell clinic websites. The reality varies considerably. At the highest-quality programs, every patient is evaluated by at least one physician, often two, before any treatment decision is made. The physician reviews medical history, current condition, imaging, comorbidities, and goals, and signs off on (or declines) the protocol.
At the lowest-quality programs, the patient is evaluated by a sales coordinator. A nurse may administer the IV. The "physician" on the website signs the standing-order paperwork without ever meeting the patient.
The middle ground, which is most common, is a brief physician check-in at the start of the visit, a sales coordinator handling everything else, and a treatment that's been determined by the protocol the patient initially called about. The physician review is real but limited.
Every Celva patient meets at least one physician, often two, with a physician greeting them in the lobby. That's not just relationship-building, it's the medical evaluation that gates whether treatment proceeds at all. The Celva physician roster: Dr. Cesar Amescua, Dr. Rocio Ambrosio Nuño, and Dr. Alejandro Castillo.
The infrastructure behind the IV line, matters.
Most stem cell treatments have no acute complications. But "most" is not "all," and the difference between a clinic that can handle a complication and one that can't is significant.
- No on-site oxygen or crash cart
- No surgical or ICU backup
- No on-site physicians beyond IV nurse
- No hospital affiliation
- Emergency response: call 911 + wait
- Full surgical capability on premises
- ICU on the floor above
- Emergency department in the same building
- Full clinical staff on site at all hours
- Response time: same building, same minute
A patient who has an unexpected reaction during an IV in a strip-mall clinic is in trouble. Emergency response means waiting for an ambulance. A patient who has an unexpected reaction in a hospital setting is already in the place where complications are managed.
This isn't an academic distinction. It's one of the structural reasons Celva operates inside Hospital Angeles rather than in a standalone clinic, and one of the reasons we've never had something go wrong during treatment, even after thousands of treatments. The infrastructure isn't there because we expect to use it. It's there as a safety floor.
The patient's checklist for any clinic.
If you're evaluating a stem cell program, these are the questions that surface most of the categorical differences described above. None are unreasonable. None should be hard for a credible clinic to answer.
Twelve questions that surface everything.
Each maps to one of the six divergences. If a clinic can answer all twelve directly and consistently, they're operating a real program. If they deflect, generalize, or pivot to testimonials, that's also a signal.
- What is the cell source?Autologous bone marrow, autologous fat, allogeneic cord, or something else?
- If allogeneic, what's the donor age and screening process?A screened newborn donor is the standard for serious international programs.
- Who manufactures the cells?Your own lab, or an outside supplier? If outside, who?
- What's the cleanroom classification of the manufacturing lab?ISO 7 is the standard for serious cGMP cell manufacturing.
- What's the full testing panel run on every batch?A serious lab can list it: identity, sterility, mycoplasma, endotoxin, viability, count, morphology.
- Is viability tested on the day of treatment?A binary question with a binary answer.
- What viability minimum do you accept for clinical release?Look for a specific number measured post-thaw, on the lot you receive, not a higher pre-freeze figure.
- Will you provide the certificate of analysis for my dose?A serious clinic provides it on request.
- How many physicians will I see during my evaluation and treatment?The answer should be at least one, ideally two.
- What's the medical infrastructure around the treatment site?Hospital, surgical center, urgent care backup, or strip-mall clinic?
- What's your protocol if a serious adverse event occurs during or after treatment?A real answer involves named procedures and named partners, not a generic reassurance.
- How long has the medical team been doing this work?Years of experience and months of experience produce different programs.