PRP (Platelet-Rich Plasma)

This page is for general educational purposes and does not provide medical advice, diagnosis, or a treatment recommendation.

Platelet-Rich Plasma (PRP): What It Is, Where Evidence Is Strongest, and What to Ask

Platelet-rich plasma (PRP) is an established, physician-performed injection treatment made from a patient’s own blood. It is used in mainstream medical practice, particularly in orthopedics, sports medicine, physical medicine and rehabilitation, dermatology, and some surgical settings. It is used most often for certain joint and tendon problems and is also offered for hair loss and cosmetic concerns.

PRP’s acceptance in medical practice does not mean the evidence is equally strong for every use. Research is most developed for knee osteoarthritis and several tendon conditions, but study results vary and preparation methods are not standardized. PRP may reduce pain or improve function for some patients, particularly when it is used for an appropriately diagnosed condition as part of a broader care plan. It has not been shown to reliably regrow severely damaged cartilage or replace surgery when surgery is otherwise indicated.

PRP does not work for everyone, and improvement—when it occurs—is usually gradual rather than immediate. A qualified clinician should explain why PRP is being considered, what alternatives exist, and how likely it is to help the specific condition being treated.

What Is PRP?

PRP is prepared by drawing a small amount of blood and processing it in a centrifuge. This separates the blood into components and produces plasma containing a higher concentration of platelets than the original sample. The clinician then injects the preparation into the target area, sometimes with ultrasound guidance.

Platelets are best known for helping blood clot, but they also release proteins involved in inflammation, cell signaling, and tissue repair. PRP is intended to concentrate those signals at an injured or symptomatic site. That biological rationale is plausible, but it should not be confused with proof that PRP rebuilds tissue or cures a particular condition.

“PRP” is not one uniform product. Preparations can differ in platelet concentration, white-blood-cell content, red-blood-cell content, activation method, injection volume, and number of treatments. Those differences make studies difficult to compare and may help explain why outcomes vary between clinics and research trials.

What Is PRP Used For?

Physicians use PRP in established clinical specialties for knee osteoarthritis, tennis elbow, rotator-cuff tendinopathy, patellar and Achilles tendon problems, plantar-fascia pain, muscle or ligament injuries, and other musculoskeletal conditions. It is also used in some surgical settings and is offered by physicians for androgenetic alopecia, commonly called male- or female-pattern hair loss.

A listing of a condition does not mean PRP is proven or appropriate for every patient with that diagnosis. The location and severity of an injury, the accuracy of the diagnosis, prior treatment, overall health, and the PRP preparation used can all affect the decision.

What Does the Evidence Show?

Knee osteoarthritis: This is one of the most studied uses. The American Academy of Orthopaedic Surgeons states that PRP may reduce pain and improve function in symptomatic knee osteoarthritis, but its recommendation is limited because studies use different products and protocols. PRP should be discussed as one option for symptom management—not as a proven way to restore normal cartilage or stop arthritis from progressing.

Tendon conditions: Results depend on the tendon and the comparison treatment. Research on lateral epicondylitis, or tennis elbow, is mixed. Some analyses find better longer-term results than corticosteroid injections, while placebo-controlled research has not consistently shown a meaningful advantage. Reviews of rotator-cuff tendinopathy suggest possible longer-term pain improvement, but functional benefits and optimal protocols remain uncertain. Evidence for Achilles tendinopathy has also been inconsistent.

Hair loss: Studies of PRP for androgenetic alopecia report possible improvement in hair density. However, reviews also identify substantial differences in treatment protocols, study quality, and outcome measurement. PRP is therefore better described as a developing option than a guaranteed method of hair restoration.

Evidence for many other advertised uses is limited or preliminary. Be cautious when a clinic applies results from one body part or diagnosis to a different condition, promises cartilage or tissue regrowth, or presents PRP as universally effective.

What to Expect

A clinician should first confirm the diagnosis and review medications, medical conditions, previous treatments, and reasonable alternatives. During the procedure, blood is drawn, processed, and injected into the treatment area. Ultrasound guidance may be used when precise placement matters.

Patients commonly experience temporary soreness, swelling, bruising, or stiffness after an injection. The clinician may recommend short-term activity modification followed by a rehabilitation program. Protocols range from a single injection to a series, but more injections are not automatically better. Benefits, when they occur, may take several weeks or months to become noticeable.

Risks and Limitations

Because PRP is made from the patient’s own blood, allergic reactions to the PRP itself are uncommon. It is still an injection procedure, so risks include pain, bleeding, infection, injury to nearby tissue, and failure to improve. Symptoms can temporarily worsen after treatment. Risks may differ when PRP is combined with an anesthetic, another injected product, or surgery.

PRP may not be suitable for everyone. A provider should review active infection, certain blood or platelet disorders, anemia, cancer-related considerations, pregnancy when relevant, and medications or supplements that affect bleeding or platelet function. Patients should not stop prescribed medication unless the prescribing clinician advises them to do so.

Insurance coverage varies and many uses are paid for out of pocket. Ask for the full expected cost, including imaging, facility fees, follow-up visits, rehabilitation, and additional injections.

Questions to Ask a PRP Provider

• What is my exact diagnosis, and how was it confirmed?
• What evidence supports PRP for this specific condition and stage of disease?
• What are the alternatives, including rehabilitation, medication, other injections, or surgery?
• How is your PRP prepared, and why do you use that preparation?
• Will you use image guidance to place the injection?
• How many treatments do you recommend, and what evidence supports that schedule?
• What outcome is realistic, and how will we decide whether the treatment worked?
• What are the risks in light of my health conditions and medications?
• What should I do before and after the procedure?
• What is the total cost, and what happens if I do not improve?

Sources and Further Reading

1. American Academy of Orthopaedic Surgeons. Management of Osteoarthritis of the Knee (Non-Arthroplasty): Evidence-Based Clinical Practice Guideline.
2. Dubin J, et al. American Academy of Orthopaedic Surgeons Technology Overview Summary: Platelet-Rich Plasma for Knee Osteoarthritis. J Am Acad Orthop Surg. 2024. PMID: 38295392.
3. Simental-Mendía M, et al. Clinical efficacy of platelet-rich plasma in the treatment of lateral epicondylitis: a systematic review and meta-analysis of randomized placebo-controlled clinical trials. Clin Rheumatol. 2020. PMID: 32103373.
4. Chen XT, et al. The efficacy of platelet-rich plasma for improving pain and function in lateral epicondylitis: a systematic review and meta-analysis with risk-of-bias assessment. Arthroscopy. 2021. PMID: 33964386.
5. Lin MT, et al. Effectiveness of platelet-rich plasma injection in rotator cuff tendinopathy: a systematic review and meta-analysis of randomized controlled trials. Diagnostics. 2020. PMID: 32231127.
6. Kieling L, et al. Is autologous platelet-rich plasma capable of increasing hair density in patients with androgenic alopecia? An Bras Dermatol. 2024. PMID: 39013743.