PRP vs. Donor-Derived "Stem Cell" Products for Joint Pain

Umbilical cord, Wharton’s jelly, amniotic, and exosome injections are widely marketed as "stem cell therapy" for joint pain. The FDA does not approve these products for joints — and in 2024 sent letters to companies selling them. Here is what that means for you.

If you have joint or tendon pain that will not go away, you have probably seen injections advertised as "stem cell therapy" — usually described as coming from umbilical cord, amniotic fluid, Wharton’s jelly, or exosomes, and often sold at a premium price. Here is the bottom line: none of these products is FDA-approved to treat an orthopedic condition, the science does not back up the marketing, and there is often no reliable proof they even contain the functional stem cells you are promised.

That is not one clinic’s opinion. It is the FDA’s stated position, and in 2024 the agency acted on it. The rest of this article explains what these products actually are, what the FDA has said and done, and how PRP differs in the ways that matter.

What the FDA has actually said

The FDA allows certain human tissue products to be sold without full drug approval — but only under strict conditions: the tissue must be minimally processed and used for roughly the same purpose it served in the original donor. Injectable umbilical-cord, Wharton’s jelly, and amniotic-fluid products marketed for joints fail both tests. The FDA has determined they are heavily processed and used for a purpose the original tissue never served, which means they require drug or biologic approval that the companies selling them do not have. Exosomes are their own category — they are signaling particles released by cells, not stem cells — but the same logic applies: products marketed as therapeutic exosome injections also require FDA approval they do not have.

In 2024 the FDA put this position into action, sending warning letters to specific companies — including Neobiosis, LLC (June 2024) and Evolutionary Biologics, Inc. (December 2024) — telling them their products could not legally be sold without FDA approval. It is also worth being clear about off-label use: a physician can sometimes use an approved product outside its approved indication, but that does not apply here. Off-label use requires a product that is approved for something. These are not.

"FDA registered" does not mean "FDA approved"

This is the single most common way patients get misled, so it is worth pausing on.

Companies that handle human tissue are often required to register their facilities with the FDA. That registration is paperwork — it tells the government the company exists. It says nothing about whether the product is safe, effective, or even legal to sell. FDA approval is completely different: it means the FDA reviewed clinical data and determined a product is safe and effective for a specific use. The two are not remotely the same thing.

So a clinic can truthfully say a product is "FDA registered" while it has no FDA approval at all for treating your joint. If someone leans on the word "registered," that is your cue to ask exactly what it means.

What these products really contain

The products are sold as being full of living stem cells that travel to your injury and grow new tissue. When independent researchers tested selected commercial products marketed for joint pain, they did find some viable cells — but not the colony-forming connective-tissue progenitor cells that would be needed to support the regenerative claims in the advertising. The specific functional stem cells patients are led to expect were not demonstrated in the products tested. It is also worth noting that products vary between manufacturers, so no single study proves every product on the market is identical — but the reasonable takeaway is that patients should ask for independent, product-specific testing rather than accepting marketing claims at face value.

So where does PRP fit in?

PRP (platelet-rich plasma) is different in the way that matters most: it is made from your own blood. Platelets release growth factors and signaling proteins involved in clotting, inflammation, and tissue repair. PRP concentrates them from your own blood sample and places them directly at the injured tendon or arthritic joint, with the goal of improving pain and function. Because it is autologous — drawn from and returned to you — there is no donor to screen and nothing for your body to reject. It is not a stem-cell treatment and should not be marketed as one.

PRP is not FDA-approved for knee osteoarthritis, tendinopathy, or any specific orthopedic diagnosis. But it is in a fundamentally different regulatory position. A physician using PRP is making a treatment decision with your own blood — there is no manufactured commercial product, no donor, no company selling a drug. That is a different situation in the FDA’s eyes from a company distributing an allogeneic product the FDA considers an unapproved drug.

Some PRP preparation devices do carry FDA clearance, though typically for specific narrow uses such as combining PRP with bone graft material. That device clearance is not approval of PRP injections for joints or tendons, and not all PRP systems have it. The honest summary is that PRP’s regulatory situation is genuinely different from the donor products — not because it has an approval they lack, but because it is your own blood used in a medical context, not a commercially manufactured drug.

Beyond the regulatory distinction, PRP avoids the donor-transmission, donor-screening, and tissue-compatibility concerns introduced by allogeneic products, and it has a substantially larger orthopedic evidence base. For knee osteoarthritis and some tendinopathies in particular, randomized trials and meta-analyses have found longer-term outcomes comparable or superior to corticosteroid injections, though results vary by condition and PRP protocol. The donor products have almost no solid research for orthopedic use, and independent reviewers keep reaching the same conclusion: the marketing has run far ahead of the science.

Safety and cost

Because PRP is your own blood, there is nothing to catch from a donor and nothing to reject. It is not completely risk-free — any injection can cause temporary soreness and, rarely, infection — but the risks are small and well understood.

Donor products carry an extra layer of risk because the material comes from another person. This is not theoretical: the CDC has documented patients who developed serious bloodstream and joint infections and required hospitalization after receiving contaminated non-FDA-approved umbilical-cord-blood-derived products. These products are also often far more expensive than PRP — sometimes thousands of dollars for a single injection — despite the weaker evidence and the FDA’s position.

How Dr. Borys approaches this

Dr. Borys uses PRP, prepared from your own blood and placed with ultrasound guidance, as the main regenerative injection in his practice. For the joint and tendon conditions he treats, it has a substantially larger and more developed orthopedic evidence base than commercially marketed donor birth-tissue or exosome injections.

He does not offer donor products sold as amniotic fluid, umbilical cord, Wharton’s jelly, or exosomes. The FDA classifies these as unapproved drugs for orthopedic use — a position it backed with enforcement letters to manufacturers in 2024 — independent testing has not confirmed they contain the cells patients are promised, and the clinical evidence does not support the price. That position is not fixed — if well-designed trials change the picture, it will be worth revisiting. But the bar is good evidence, not confident marketing.