What PRP Is
PRP is made by drawing a small sample of blood and spinning it in a centrifuge so the platelet-rich portion can be separated and concentrated. The result is a treatment that may provide a higher concentration of growth factors than normal blood. Because PRP comes from your own blood, it is different from donor tissue products and different from stem cell therapies.
How PRP May Work
PRP is intended to improve the biologic environment of injured or irritated tissue. The concentrated platelets may provide growth factors and repair signals that support healing, improve local tissue signaling, and help calm inflammation in a painful area. Research also suggests PRP may help reduce some of the inflammatory signals and matrix-degrading enzymes that contribute to cartilage breakdown, which is one reason it continues to attract attention in knee osteoarthritis and other degenerative conditions.
Is PRP a Stem Cell Treatment?
PRP is not a stem cell injection. Its main effect comes from platelets, growth factors, and biologic signaling rather than from adding stem cells to the joint or tendon. It still belongs to the broader regenerative medicine conversation because it may help create a more favorable healing environment and support recovery in selected orthopedic conditions.
What PRP May Help
PRP has shown the most encouraging use in chronic tendon disorders and in mild to moderate knee osteoarthritis. It is also used in selected sports medicine and surgical settings, although the evidence is stronger in some areas than in others. For many patients, the main appeal is the chance to improve pain and function while staying within a nonsurgical treatment plan.
What Treatment Is Like
A PRP procedure is usually performed in the office. Blood is drawn from the arm, processed to concentrate the platelets, and then injected into the target area, often with image guidance to improve precision. Most patients like that the process is straightforward and does not require donor tissue, a marrow harvest, or surgery.
Recovery and Expectations
PRP usually works gradually rather than instantly. Some patients feel increased soreness for a short period after treatment, especially when a tendon is injected, and meaningful improvement may take weeks rather than days. PRP often works best when it is part of a larger treatment plan that also addresses strength, mobility, biomechanics, loading, and the reason the tissue became irritated in the first place.
Safety and Regulatory Information
PRP is one of the most widely used orthobiologics in clinical practice and carries a favorable safety profile because the injection comes entirely from your own blood. The centrifuge systems used to prepare PRP are FDA-cleared medical devices, and the procedure itself is a well-established form of off-label use, which is a normal and accepted part of medical practice across many specialties. While the FDA has not approved PRP specifically for orthopedic indications such as osteoarthritis or tendonitis, off-label use of FDA-cleared technology is how many of the most effective treatments in medicine are delivered. Florida's stem cell statute specifically excludes blood components and blood derivative products from its scope, which means PRP is among the least restricted orthobiologic options available and does not require the additional consent framework that applies to stem cell therapies.
Bottom Line
PRP is a positive and practical nonsurgical option for patients who want to use their own blood-derived healing signals to support recovery. It does not contain stem cells, but it may provide concentrated growth factors and may help reduce some of the inflammatory and enzyme-driven processes that contribute to ongoing tissue irritation and cartilage wear. For the right patient, PRP can be a very reasonable way to improve pain, support function, and stay active while trying to delay or avoid more invasive treatment when appropriate.
Sources
- American Academy of Orthopaedic Surgeons. Platelet-Rich Plasma (PRP). OrthoInfo.
- American Academy of Orthopaedic Surgeons. Orthobiologics (Regenerative Medicine) FAQ. OrthoInfo.
- U.S. Food and Drug Administration. Important Patient and Consumer Information About Regenerative Medicine Therapies.
- Florida Legislature. Section 458.3245, Stem cell therapy.
- van Buul GM, et al. Platelet-rich plasma releasate counteracts effects of an inflammatory environment on genes regulating matrix degradation and formation in human chondrocytes. American Journal of Sports Medicine. 2011.
- Gato-Calvo L, et al. Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates. Biology. 2019.
- Filardo G, Mandelbaum BR, Muschler GF, Rodeo SA, Nakamura N, eds. Orthobiologics: Injectable Therapies for the Musculoskeletal System. Springer; 2022.