Regenerative & pain
PRP vs. stem cell therapy: how the options actually differ
They are often sold side by side, as if one were simply the premium version of the other. They are not. Here is how platelet-rich plasma and cell-based injections differ in source, regulation, evidence, recovery and cost.
Short answer
PRP is a concentrate of your own platelets, prepared in minutes with an FDA-cleared device; its use for joints and tendons is off-label, and it has the larger body of trial evidence, with mixed results. Stem cell (cell-based) products come from your bone marrow, fat or donated birth tissue; none is FDA-approved for orthopedic or pain use, they cost more, and the best trials have not shown them to outperform standard injections for knee arthritis.
Side by side
| PRP | Cell-based (“stem cell”) products | |
|---|---|---|
| Source | Your own blood, drawn at the visit | Your bone marrow or fat (second procedure site), or donated umbilical-cord / Wharton’s-jelly / amniotic tissue |
| What is injected | Platelets and the growth factors they release | Cells and/or tissue matrix; some processed birth-tissue products contain few living cells |
| Regulatory status for pain | Off-label | Not FDA-approved |
| Evidence base | Many randomized trials; results vary by condition and preparation | Fewer, smaller trials; largest knee trial showed no advantage over steroid |
| Typical recovery | Soreness for a few days; activity modification; rehabilitation | Similar, plus harvest-site soreness for autologous products |
| Relative cost | Lower | Higher |
What PRP is — and what it is not
Platelet-rich plasma is made by drawing a small amount of your blood and spinning it in a centrifuge so that platelets are concentrated in a small volume of plasma. Platelets release signaling proteins involved in the body’s response to injury, which is the rationale for injecting them into a painful tendon or joint.
PRP is not a single standardized product. Preparation systems differ in platelet concentration, whether white blood cells are included, and whether the PRP is activated before injection. That variability is one reason trial results disagree: two “PRP” studies may not be testing the same thing.
What “stem cell therapy” means in an orthopedic clinic
In U.S. pain and orthopedic clinics, “stem cell therapy” usually means one of three things: bone marrow aspirate concentrate drawn from the back of your pelvis; cells derived from a small fat harvest; or a processed product made from donated umbilical-cord, Wharton’s-jelly or amniotic tissue. These are very different products with different processing, regulation and evidence. Their proposed benefit in joints is thought to come mainly from signaling to surrounding tissue rather than cells turning into new cartilage. Stem cell therapy terms, explained.
At PrimeCell, the cellular options are umbilical-cord-tissue-derived mesenchymal stem cell injections and perinatal (birth-tissue) allograft injections, and exosome products are offered in selected cases. All three are investigational and not FDA-approved for any orthopedic or pain use, and each is considered only after an evaluation and written informed consent. PRP (including a PRP gel preparation) and PRF are also offered, as off-label uses. Everything PrimeCell offers for pain, with FDA status.
What the evidence shows
Knee osteoarthritis. Several trials and meta-analyses report that PRP can reduce knee pain more than hyaluronic acid or saline for some patients, but the largest placebo-controlled trial, RESTORE (288 patients), found no difference between PRP and saline in pain or cartilage volume at 12 months.1 For cell-based products, a 480-patient randomized trial found that bone-marrow, fat-derived and umbilical-cord injections were not better than a corticosteroid injection at one year.2 The American College of Rheumatology recommends against both PRP and stem-cell injections for knee and hip osteoarthritis.3
Tendons. Evidence is condition-specific. A multicenter trial in chronic tennis elbow reported better pain scores with leukocyte-enriched PRP than with a control injection at 24 weeks.4 In chronic Achilles tendinopathy, by contrast, PRP did not outperform placebo in two randomized trials.5,6 Cell-based tendon trials are small.
Overall. PRP has more evidence and more of it is mixed. Cell-based products remain investigational for pain. Neither should be presented as proven to regrow tissue.
How a physician decides between them
- Diagnosis first. A tendon problem, early arthritis and nerve pain are different questions with different evidence.
- Response to conventional care. Strengthening, load management and weight management often come first and continue afterwards. For knees, losing weight meaningfully reduces joint load — see GLP-1 medical weight management.
- Evidence for your specific condition, not for “regenerative medicine” in general.
- Regulatory status and consent. Cell-based products require the Florida disclosure and written informed consent; PRP does not carry that requirement but still requires consent.
- Cost and risk tolerance. Paying more for a less-proven product is a choice that deserves a clear-eyed discussion.
At PrimeCell, many evaluations end with neither option — and that is a legitimate result of an honest assessment.
If you are comparing Orlando clinics
Ask each clinic what exactly is being injected, who makes it, its FDA status for your condition, what the randomized evidence shows, and the total written cost. Be wary of seminars, same-day packages and any claim of FDA approval. How to compare regenerative clinics.
Frequently asked questions
Is PRP a stem cell therapy?
No. PRP contains platelets and plasma from your blood, not stem cells.
Which works better for knee arthritis, PRP or stem cells?
Neither has been shown to be reliably better than standard care in the largest trials. PRP has more supporting studies; cell-based products are investigational and more expensive.
Can PRP and stem cells be combined?
Some clinics combine them. There is little high-quality evidence that combining improves outcomes, and it adds cost.
How many PRP injections are usually needed?
Protocols vary from one to three injections depending on the condition and the preparation. Your plan is individualized after evaluation.
Are either covered by insurance?
Usually not for orthopedic pain. PrimeCell is self-pay and provides a written estimate before any procedure. How pricing works.
References
- Bennell KL, Paterson KL, Metcalf BR, et al. Effect of intra-articular platelet-rich plasma vs placebo injection on pain and medial tibial cartilage volume in patients with knee osteoarthritis: the RESTORE randomized clinical trial. JAMA. 2021;326(20):2021-2030. doi:10.1001/jama.2021.19415
- Mautner K, Gottschalk M, Boden SD, et al. Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial. Nat Med. 2023;29:3120-3126. doi:10.1038/s41591-023-02632-w
- Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 ACR/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Care Res. 2020;72(2):149-162. doi:10.1002/acr.24131
- Mishra AK, Skrepnik NV, Edwards SG, et al. Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients. Am J Sports Med. 2014;42(2):463-471. doi:10.1177/0363546513494359
- de Vos RJ, Weir A, van Schie HTM, et al. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. JAMA. 2010;303(2):144-149. doi:10.1001/jama.2009.1986
- Kearney RS, Ji C, Warwick J, et al. Effect of platelet-rich plasma injection vs sham injection on tendon dysfunction in patients with chronic midportion Achilles tendinopathy: a randomized clinical trial. JAMA. 2021;326(2):137-144. doi:10.1001/jama.2021.6986
General education, not medical advice. PRP and cell-based products are not FDA-approved for orthopedic or pain conditions; candidacy is determined at an individual evaluation, and results vary and are not guaranteed.