How many PRP injections are needed for this blood-based shot depends on the first result

How many PRP injections are needed has no fixed answer

Some clinics plan one treatment. Some research tested a course of three, often a week apart. That doesn't make either schedule right for every joint. If the first shot brings a useful change, a doctor may stop rather than add another. If it doesn't help, the doctor should explain why another shot could be worthwhile. Care for a tendon, the cord joining muscle and bone, may differ from care for a knee.

More shots don't always mean more relief.

Chairs, stairs, sleep and walking show whether it helped

A pain score is the number you give the soreness. That number helps, but ordinary tasks tell more. Note how easily you rise from a chair and how far you walk before aching. Sleep and stair use matter too. Compare the same tasks before each visit. One good afternoon isn't enough to judge the treatment. A sore day soon after the shot isn't enough either. PRP may take longer to judge than a steroid shot.

The clearest answer comes from what you can do each day.

Repeated visits must fit the calendar and the cost

A course brings more trips and more days when the joint may be sore. Plan around work, travel and the ride home. Winter residents may need the last check before leaving Scottsdale. Ask when the clinic will decide whether to continue. Joint PRP is rarely covered, so get the total cost in writing before treatment. The clinic should state what each visit includes and whether a later check costs more. If the schedule changes, ask whether the total changes.

The number of visits must make sense for the joint, time and budget.

Sources

1. A meta-analysis of seven high-quality randomized trials (575 patients) comparing single-dose with multiple-dose PRP for knee osteoarthritis found triple-dose PRP produced significantly better VAS scores than a single dose at 12 months (P<.0001), while double-dose did not differ significantly from single-dose at 12 months. Adverse events did not differ significantly between the double-dose or triple-dose arms and single dose.

   Tao X, Aw AAL, Leeu JJ, et al. — Three Doses of Platelet-Rich Plasma Therapy Are More Effective Than One Dose of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis. Arthroscopy, 2023. DOI: 10.1016/j.arthro.2023.05.018.

2. An earlier meta-analysis of five randomized trials (301 patients) found that at six months, single and multiple PRP injections produced similar pain improvement with no significant difference, while knee function favoured multiple injections. The two meta-analyses together support a modest functional advantage for a course of injections rather than one, without settling the number.

   Vilchez-Cavazos F, Millan-Alanis JM, Blazquez-Saldana J, et al. — Comparison of the Clinical Effectiveness of Single Versus Multiple Injections of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis. Orthopaedic Journal of Sports Medicine, 2019. DOI: 10.1177/2325967119887116.

3. In the RESTORE trial - the largest placebo-controlled PRP trial in knee osteoarthritis - 288 adults aged 50+ with symptomatic Kellgren-Lawrence grade 2-3 medial knee OA received three weekly intra-articular injections of leukocyte-poor PRP from a commercial system or saline placebo. At 12 months the mean change in knee pain was -2.1 points with PRP versus -1.8 with saline (difference -0.4; 95% CI -0.9 to 0.2; P=.17) against a minimum clinically important difference of 1.8, and the change in medial tibial cartilage volume was -1.4% versus -1.2% (difference -0.2%; 95% CI -1.9% to 1.5%; P=.81). Twenty-nine of 31 prespecified secondary outcomes showed no significant between-group difference. The authors concluded the findings do not support use of PRP for knee OA.

   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. DOI: 10.1001/jama.2021.19415.

4. The American Academy of Physical Medicine and Rehabilitation convened a technical expert panel that ran a structured literature review (2023, updated through June 2025) and a modified Delphi process, and issued five evidence-based clinical recommendations plus 11 consensus-based best practices for PRP in knee osteoarthritis. The statement is explicit that orthobiologic therapies 'remain an evolving area of practice' and that robust, dose-dependent randomized controlled trials are still needed to establish PRP's clinical effects.

   Borg-Stein J, Jayaram P, Colorado BS, et al. — AAPM&R guidance statement on platelet rich plasma for knee osteoarthritis. PM&R, 2026. DOI: 10.1002/pmrj.70144.