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PRP vs Cell-Based Treatments

Platelet-rich plasma is made from your own blood; cell-based products use stem or stromal cells. This page compares trial evidence for knee osteoarthritis, regulation and risks without naming a winner.

Content last updated . This page has not been medically reviewed.

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Quick answer
Platelet-rich plasma (PRP) and cell-based injections (often called "stem cell" treatments) are marketed for similar problems, especially knee osteoarthritis, but they are different products with different evidence and different rules. This page compares them and declares no winner. It describes research; it is not a recommendation. Evidence labels used: approved medicine, promising but limited, mixed, insufficient evidence, marketing claim.

Definitions

  • PRP is obtained by spinning a sample of the patient's blood at high speed and keeping a platelet-rich fraction. [1] It is a blood product, not a cell therapy. Health Canada states that PRP treatments are not the same as cell therapies. [1]
  • Cell-based injections for joints are often mesenchymal stem or stromal cells (MSCs) given by injection into the joint. [2]

See Platelet-Rich Plasma: What Trials Show by Condition and Mesenchymal Stromal Cell Research.

The difference at a glance (knee osteoarthritis)

PRPMSC / cell-based injections
SourcePatient's own blood [1]Mesenchymal stem or stromal cells, compared in trials with placebo, hyaluronic acid or other treatments [2]
Pooled trial evidenceMixed: a 288-person trial found no benefit at 12 months, [3] a meta-analysis of 18 trials found benefit [4]A meta-analysis of 11 trials found benefit; authors called for larger trials [2]
Regulatory (US)Not verified in the sources read for this pageNone of these products has been approved for orthopedic conditions such as osteoarthritis [5]
Regulatory (Canada)Not reviewed for any therapeutic use; no applications received as of the 2019 statement [1]Not verified in the sources read for this page

What the trials show

PRP. The RESTORE trial (humans, randomized, placebo-controlled, 288 adults aged 50 or older with mild to moderate knee osteoarthritis) found no significant difference in pain or cartilage volume at 12 months, and 29 of 31 secondary outcomes also showed no difference. The authors concluded the findings do not support PRP for knee osteoarthritis. [3] A 2025 meta-analysis of 18 randomized trials (1,995 patients) found PRP better than placebo for pain and function, with high-platelet PRP doing better than low-platelet PRP. [4] These two results disagree, so the evidence label is mixed. The meta-analysis reported that platelet concentration influenced the result, which suggests preparation differences matter; the sources read here do not settle the question. [4]

Cell-based injections. A 2025 meta-analysis of 11 randomized trials (811 patients) found larger improvements in pain and function with MSC injections than with controls, including at 24 months. The authors called the approach promising and said large-scale trials are needed. [2] Evidence label: promising but limited.

Across both. A 2026 systematic review of placebo-controlled trials of PRP, MSCs and similar products found 14 trials; 8 showed pain improvement and 10 showed function improvement, but heterogeneity and risk of bias were frequent. The same review found news coverage was mostly favorable and often left out drawbacks. [6]

Questions to ask a clinician

  • What exactly is being injected, and how is it prepared?
  • Is it approved for my condition, or part of a regulated trial?
  • What do randomized, placebo-controlled trials show for my specific problem?
  • Which established options exist, and what happens if I do nothing new?

Frequently asked questions

Is PRP the same as a stem-cell treatment?

No. PRP comes from a spun sample of your blood and is not a cell therapy, according to Health Canada. [1]

Does PRP work for knee osteoarthritis?

Results are mixed. A 288-person placebo-controlled trial found no benefit at 12 months, [3] while a 2025 meta-analysis found benefit over placebo. [4]

Are stem-cell injections approved for knee pain in the US?

The FDA says none of these regenerative products has been approved for orthopedic conditions such as osteoarthritis. [5]

Why do news stories sound more positive than the trials?

One review found media coverage was mostly favorable and seldom mentioned drawbacks, while the trials were inconsistent. [6]

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

Safety and regulation
The FDA says it has received reports of blindness, tumor formation and infections with unapproved regenerative products, and that a clinic's listing on clinicaltrials.gov does not mean a product is legally marketed. [7] Health Canada notes PRP preparation falls under the practice of medicine when a practitioner takes blood from a patient and gives it back in a single procedure. [1] Rules differ by country and change over time; this is not legal advice. See Regulatory Status of Regenerative Products by Product and Indication.
References
  1. Health Canada, clarifies position on Platelet Rich Plasma treatments (2019). Read 2026-10-22.
  2. Meta-analysis of mesenchymal stem cell therapy for osteoarthritis, Front Cell Dev Biol 2025 (PubMed 41567976). Read 2026-10-22.
  3. RESTORE trial of PRP for knee osteoarthritis, JAMA 2021 (PubMed 34812863). Read 2026-10-22.
  4. Meta-analysis of PRP injections for knee osteoarthritis, Am J Sports Med 2025 (PubMed 39751394). Read 2026-10-22.
  5. FDA, Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. Read 2026-10-22.
  6. Systematic review of injectable orthobiologics and news media, Orthop J Sports Med 2026 (PubMed 42221207). Read 2026-10-22.
  7. FDA, Important Patient and Consumer Information About Regenerative Medicine Therapies. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.