PRP vs. Stem Cell Therapy for the Shoulder: What’s the Difference?

By Dr. Benjamin DuBois, MD — board-certified orthopedic shoulder surgeon
Medically reviewed by Benjamin DuBois, MD | September 2026

Patients ask me about this constantly, usually after seeing an ad or attending a seminar. The pitch is compelling: why settle for platelets when you could have stem cells?

It is a fair question. Answering it well means separating three things that often get blurred together — what is actually in the syringe, what the research supports, and what the words in the advertisement legally mean.

What are you actually buying when a clinic sells “stem cell therapy” for a shoulder?

Almost always, one of two things.

Bone marrow aspirate concentrate (BMAC). Bone marrow is drawn from the pelvis with a large needle, then spun in a centrifuge to concentrate its cellular fraction. That concentrate does contain mesenchymal stromal cells — but they are a very small minority of what is in the sample. The bulk is other cell types, platelets, and plasma.

Adipose-derived preparations. Fat is harvested, usually by mini-liposuction, and processed into what is often called stromal vascular fraction. The Ninth Circuit has held that this preparation constitutes a drug under federal law — a meaningful legal distinction discussed below.

There is a third category worth naming: amniotic, umbilical, or “birth tissue” products, sold in vials from an outside supplier and frequently marketed as containing live stem cells. In commercially processed and frozen form, they generally do not contain meaningful numbers of viable cells. If a product arrived in a box, that is worth asking about.

Are stem cell injections FDA approved for shoulder problems?

No. As of today, no stem cell product has FDA approval for any orthopedic condition — not rotator cuff tears, not shoulder arthritis, not tendinopathy. The FDA’s approvals in this space cover hematopoietic stem cell transplantation for blood cancers and a limbal stem cell therapy for certain corneal injuries. That is the list.

If you are told a shoulder injection is FDA approved, that statement is not accurate.

The regulatory framework explains why this gray area exists. Cell and tissue products fall into two tiers. Section 361 products receive lighter oversight, but only if they meet four criteria, including minimal manipulation and homologous use — meaning the cells perform the same basic function in the new location that they did in the original tissue. Everything else is regulated as a drug under Section 351 and requires full approval based on clinical trial evidence.

The FDA has stated that using mesenchymal stromal cells for orthopedic conditions is not homologous use. Many orthopedic applications therefore do not qualify for the lighter pathway.

Patient Takeaway: “Not FDA approved” is not the same as “illegal,” and it is not the same as “useless.” But it does mean the evidence standard that applies to approved drugs has not been met here, and that is worth understanding before you spend several thousand dollars.

How PRP and BMAC compare

What does the research actually show for the shoulder?

A 2026 narrative review comparing the two biologics across shoulder conditions concluded that PRP rests on a larger — though still heterogeneous — evidence base, while BMAC is biologically promising but clinically under-evidenced in the shoulder. The authors noted that standalone shoulder BMAC trials are essentially absent from the literature.

A 2025 systematic review in Arthroscopy examined BMAC used during rotator cuff repair surgery and found only eight studies, with minimal data demonstrating clinical effectiveness. Of those eight, one was a randomized controlled trial, one a matched cohort, one a case control, and five were case series. Every study found the procedure safe — but safe and effective are different findings.

Note what that means. The strongest evidence for BMAC in the shoulder concerns its use during surgery, as an augment to a repair, performed in an operating room. That is a different procedure from a standalone injection at a storefront clinic.

PRP’s evidence base is larger but genuinely mixed, and I say so on our PRP page as well. Part of the difficulty is that neither “PRP” nor “BMAC” describes a standardized product — preparation methods, cell concentrations, and volumes vary considerably between systems, which makes studies hard to compare.

I am not saying BMAC does not work. I am saying that nobody can currently tell you it does, for a shoulder, on the strength of the published evidence.

Why I have the equipment for BMAC and have not used it yet

I should be direct about where I stand, because it is relevant to how you read everything above.

My practice has the capability to perform both bone marrow aspirate concentrate and fat-derived cell preparations. I have not performed one yet.

That is a deliberate choice, not a limitation. I have been following this literature closely for years — I co-direct a course where regenerative medicine technique is part of the curriculum — and my read is that the shoulder-specific evidence has not yet reached the point where I can look a patient in the eye and recommend BMAC over PRP for most conditions. The collection is more involved, the cost is higher, and the data supporting the difference is not there yet.

I expect that will change. The biology is plausible and the research is active, and when the evidence supports it for a given condition, I will offer it and say so here. Until then, I would rather tell you I am waiting than sell you something because I can.

Why “stem cell” is usually the wrong word

The term does a great deal of marketing work and relatively little descriptive work.

When a shoulder injection is advertised as stem cell therapy, the product is typically BMAC, in which stromal cells are a small minority of the cellular content. The word carries an implication — that something will grow, replace, or regenerate damaged tissue — that the actual product has not been shown to deliver in the shoulder. Patients hear “stem cell” and picture a torn tendon being rebuilt. That is not what the evidence currently supports.

What regulators have done about stem cell marketing

This is public record and worth knowing about.

In January 2025, federal court orders permanently banned the co-founders of the Stem Cell Institute of America and several related companies from marketing any regenerative medicine treatment, and ordered more than $5.1 million in refunds and civil penalties. The FTC and the Georgia Attorney General had alleged the company marketed stem cell therapy to seniors using unsupported claims about arthritis and joint pain, recruited patients through free “educational seminars” aimed at retirement communities, charged roughly $5,000 per injection, and trained clinics nationwide to use the same approach.

An earlier FTC action against a California clinic marketing “amniotic stem cell therapy” resulted in nearly $515,000 returned to consumers.

Most practices offering these treatments are not doing anything like this. But if you have been invited to a free seminar about stem cell therapy for joint pain, it is reasonable to ask more questions than you otherwise would.

Questions worth asking before you pay for either one

These apply to PRP as much as to BMAC, and to my practice as much as anyone else’s:

• What specifically is being injected, and what is in it?
• Is this FDA approved for my condition?
• Who is performing the injection, and will it be image-guided?
• Has anyone reviewed my MRI images before recommending this?
• What is the total cost, and is a series being recommended?
• What happens if this is not appropriate for my injury — can this practice offer the alternative?

That last question matters most. A practice that only offers injections can only recommend injections. It has no way to tell you that your tear needs surgical repair, and no ability to perform it if it does.

So which is right for my shoulder?

That depends on what is wrong with your shoulder, and it cannot be answered from an advertisement — or from an article, including this one.

Here is how I approach it. I examine the shoulder, review the imaging myself, and identify the actual problem first. Some shoulders are good candidates for a biologic injection. Some need physical therapy. Some need a repair, and delaying that with an expensive injection costs the patient time as well as money.

If a biologic is reasonable for your injury, I perform every injection under live ultrasound guidance so the material reaches the structure identified on your MRI rather than the tissue near it. You can read more about why guidance matters for PRP specifically.

And if it is not reasonable for your injury, I will tell you that.

Schedule an evaluation

You do not need an MRI, a diagnosis, or a referral to be seen. If your shoulder hurts and you want to know why, that is enough.

Call (619) 462-3131 or request an evaluation. Our office is in La Mesa, and we see patients from across San Diego County.

You may also want to read our full guide to PRP injections for shoulder pain or our breakdown of what insurance does and does not cover.

Sources

• Biologic Injection Therapy for Shoulder Disorders: A Narrative Review Comparing Platelet-Rich Plasma and Bone Marrow Aspirate Concentrate. Medicina, 2026.
• Carola N, et al. Bone Marrow Aspirate Concentrate May Improve Healing and Function in Rotator Cuff Repair: A Systematic Review. Arthroscopy, 2025.
• American Academy of Orthopaedic Surgeons. Management of Rotator Cuff Injuries: Evidence-Based Clinical Practice Guideline, 2025.
• Federal Trade Commission. Stem Cell Institute Co-Founders and Companies Banned from Marketing Stem Cell Treatments, January 2025.
• U.S. Food and Drug Administration. Regulatory Considerations for Human Cells, Tissues, and Cellular and Tissue-Based Products.

This article is intended for general educational and informational purposes only and should not be considered medical advice. Reading this content does not create a physician-patient relationship. Always consult a qualified healthcare professional regarding your specific medical concerns, diagnosis, or treatment options.