Dr. Jesse Morse
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Regenerative medicine

What Is a PRP Injection? Uses, Recovery, Results, Cost

A PRP injection is a shot of platelet-rich plasma made from your own blood. A small blood sample is spun in a centrifuge to concentrate the platelets, which carry growth factors involved in healing, and the concentrate is injected into an injured tendon, ligament, muscle or joint, often under ultrasound guidance.

By Dr. Jesse Morse · November 8, 2026

What is PRP?

Blood is made of red cells, white cells, platelets and plasma, the liquid they float in. Platelets are best known for clotting, but they also carry growth factors, proteins that signal cells to repair injured tissue.

Platelet-rich plasma is plasma with far more platelets than normal blood. How concentrated it is depends on the preparation system: Hospital for Special Surgery describes 2 to 8 times the normal number, while Cleveland Clinic and the American Academy of Orthopaedic Surgeons (AAOS) describe 5 to 10 times. The idea is to deliver a dense dose of those repair signals directly to tissue that heals slowly on its own, such as a tendon or the inside of a joint.

The AAOS is candid that it is not exactly clear how PRP works. Lab studies suggest the extra growth factors may speed healing, and clinical results show it helps some people with some conditions more than others.

What happens during a PRP injection?

A PRP injection for a joint or injury takes about an hour from start to finish, according to Cleveland Clinic, and you go home the same day.

  1. Blood draw. One to a few tubes of blood are taken from your arm.
  2. Centrifuge. The blood is spun to separate the red cells from the plasma and concentrate the platelets.
  3. Numbing. The skin and target area are usually numbed with local anesthetic.
  4. Injection. The PRP is injected into the injured tendon, ligament, muscle or joint. Ultrasound lets the physician see the needle reach the exact spot.
  5. Aftercare plan. You leave with instructions on activity, pain relief and rehab for the following weeks.

Why one PRP is different from another

There is no single standard recipe for PRP. Systems differ in platelet concentration and in how many white blood cells they keep. The AAOS describes leukocyte-rich PRP as having a white cell count above that of whole blood and leukocyte-poor PRP as having less, and notes that which type works better is not yet settled. Platelet counts also differ from one patient to the next. Cleveland Clinic points to this lack of standardization as one reason study results vary.

What are PRP injections used for?

In orthopedics and sports medicine, PRP is used mainly for problems in soft tissue and joints:

  • Knee osteoarthritis, especially mild to moderate cases
  • Chronic tendon problems such as tennis elbow, golfer's elbow, Achilles tendinopathy and patellar tendinopathy (jumper's knee)
  • Rotator cuff tendinopathy and partial-thickness tears
  • Ligament sprains and muscle strains, including hamstring and calf injuries

PRP is also used in dermatology for hair loss and skin, in dentistry and in wound care. This article focuses on joints, tendons and sports injuries.

Do PRP injections work? What the research shows

The honest answer is that it depends on the condition. The evidence is strongest for knee osteoarthritis and chronic tennis elbow, more mixed for other tendon problems, and weak for several other uses.

Knee osteoarthritis

The AAOS reports a growing body of evidence that PRP helps low to moderate grade knee osteoarthritis, with some results lasting up to two years. A 2021 meta-analysis of eight studies and 648 patients found PRP reduced pain and stiffness and improved function more than cortisone injections at 3, 6 and 9 months. A 2020 meta-analysis of 20 randomized trials found PRP relieved pain better than hyaluronic acid at 6 and 12 months.

The picture is not uniformly positive. The RESTORE trial, published in JAMA in 2021, gave 288 adults with knee osteoarthritis three weekly injections of either leukocyte-poor PRP or saline. At 12 months, pain and cartilage volume were similar in both groups, and the authors concluded their findings did not support PRP for knee osteoarthritis. Differences in PRP preparation, patient selection and the comparison used help explain why trials disagree.

Tendon problems

The AAOS reports that PRP is effective for chronic tennis elbow. A systematic review of five randomized trials found cortisone worked faster for tennis elbow, but symptoms tended to return after about two months, while PRP kept improving for up to two years. Results for Achilles and patellar tendon problems look promising but are harder to separate from standard care, and Hospital for Special Surgery describes results for rotator cuff tendinopathy and partial tears as mixed.

Where PRP has not shown much benefit

According to the AAOS, adding PRP during rotator cuff repair or ACL reconstruction has shown little or no benefit, and studies in fractures have not shown a significant benefit. Evidence for acute muscle and ligament injuries is limited despite PRP's popularity with athletes.

Two things consistently improve the odds. Cedars-Sinai notes that PRP tends to work better when combined with exercise, and a correct diagnosis matters as much as the injection itself.

How long do PRP injections last?

PRP works slowly. Cleveland Clinic says initial pain relief can take a few weeks, and Cedars-Sinai describes pain and inflammation easing over three to six weeks. Fuller tissue healing can take several months, and symptoms often keep improving during that time.

When it helps, Cleveland Clinic reports the effect may last six months to a year or longer. For knee osteoarthritis, the AAOS notes some results lasting up to two years. Some people need more than one injection: in knee osteoarthritis, three injections about a week apart outperformed a single injection over 12 months in a 2021 meta-analysis. Because osteoarthritis is a chronic condition, some patients repeat treatment when symptoms return.

Recovery after a PRP injection

A typical recovery runs in stages, adjusted by the treating physician for the tissue involved:

  • First few days: soreness, swelling and stiffness at the injection site are common. Cleveland Clinic says they often last a day or two, and the AAOS notes pain can increase for the first week or two.
  • First one to two weeks: relative rest for the treated area, with normal daily activity. Strenuous exercise and heavy loading are usually held back.
  • Weeks two to six: a gradual return to activity, often with physical therapy or a home exercise program.
  • Months two to six: continued improvement for those who respond, with a progressive return to sport.

How soon can you walk after a PRP injection in the knee?

For a knee joint injection, most people walk out of the clinic on their own and walk normally that day. A 2024 systematic review of 187 knee osteoarthritis studies found that only about a third restricted activity after PRP, and the most common restriction lasted a single day. Return to activity was usually described as gradual or as tolerated. Injections into a damaged tendon, such as the Achilles or patellar tendon, may call for a more cautious plan, so follow the instructions you are given.

Why avoid anti-inflammatories and alcohol around PRP?

Anti-inflammatory medicines

PRP works by supporting the body's early inflammatory healing response. Hospital for Special Surgery says anti-inflammatory medicines should usually be stopped at the time of treatment, and Cleveland Clinic notes providers may ask you to pause NSAIDs or blood thinners beforehand. Protocols vary a lot: in the 2024 review, about half of knee studies excluded patients who had recently taken NSAIDs, and post-injection NSAID restrictions ranged from 1 day to 1,800 days. Ask your physician which pain reliever to use for soreness instead, and never stop a prescribed blood thinner without speaking to the doctor who prescribed it.

Alcohol

"Why no alcohol after a PRP injection?" is one of the most searched questions about this treatment. The reasoning is precautionary. A review of alcohol's effects on platelets found that drinking reduces platelet aggregation in the short term, and heavy or binge drinking can trigger a rebound in platelet activity afterward. Since PRP depends on platelets, many clinics ask patients to avoid alcohol for a few days before and after the injection. No clinical trial has tested whether alcohol changes PRP outcomes, so treat this as sensible caution and follow your physician's timing.

Side effects and who should not get PRP

Because PRP comes from your own blood, the risk of an allergic or immune reaction is very low. The AAOS describes the risks as minimal, with increased pain at the injection site the most common effect. Infection, tissue damage and nerve injury are rare and, per the AAOS, appear no more likely than with a cortisone injection. The main limitation is that some people do not improve, and no one can predict with certainty who will respond.

PRP may be a poor fit, or need extra caution, if you have:

  • A low platelet count, a platelet function disorder or a clotting disorder
  • Significant anemia
  • An infection at or near the injection site, or a systemic infection
  • Ongoing anticoagulant therapy

How much does a PRP injection cost?

Prices vary widely. A survey of 179 U.S. centers offering PRP for knee osteoarthritis found an average price of $714 for a single same-day knee injection. Cost depends on the preparation system, the body area treated, whether ultrasound guidance is used, how many injections are planned and local market rates.

Insurance rarely helps. The AAOS notes that few plans, including workers' compensation, provide even partial reimbursement, so most patients pay out of pocket. Because PRP is made from your own blood, it is not regulated as a drug, and its use for joints and tendons is off-label. Before booking, ask what the quoted price includes, such as the consultation, ultrasound guidance and follow-up visits.

PRP or cortisone?

Cortisone calms inflammation within days, but the relief usually fades within weeks to a few months, and repeated knee injections were linked to more cartilage loss in a two-year trial. PRP works more slowly and, in knee arthritis and tennis elbow studies, has tended to last longer. For a full comparison, including hyaluronic acid, read PRP vs cortisone injections.

PRP injections in Miami

I treat joint, tendon and sports injuries with PRP in Miami. Every plan starts with a diagnosis: a hands-on exam, a review of any imaging and, when it helps, a musculoskeletal ultrasound in the clinic so we can see the tendon or joint we are treating. If PRP is a reasonable option, I guide the injection with ultrasound and pair it with a rehab plan, an approach shaped by my years working with professional baseball medical staffs. If something else is likely to work better, I will tell you.

My clinic quotes the price before any treatment. Learn more about PRP injections in Miami, compare PRP and cortisone, or book a consultation.

Frequently asked questions

How long do PRP injections last?

When PRP helps, Cleveland Clinic reports the effect may last six months to a year or longer, and the American Academy of Orthopaedic Surgeons notes some knee osteoarthritis results lasting up to two years. Relief builds gradually over several weeks, and some people need more than one injection.

How soon can I walk after a PRP injection in the knee?

Most people walk out of the clinic the same day. In published knee osteoarthritis studies, only about a third restricted activity at all, and the most common restriction lasted one day. Your physician may ask you to limit long walks, running and heavy lifting for a short period, so follow the plan you are given.

Why should I avoid alcohol after a PRP injection?

Alcohol can reduce platelet aggregation shortly after drinking, and the treatment depends on platelets doing their job, so many clinics ask patients to skip alcohol for a few days around the injection. No clinical trial has measured whether drinking changes PRP results, so this advice is a precaution. Follow the timing your own physician gives you.

Can I take ibuprofen after a PRP injection?

Many physicians ask patients to avoid ibuprofen, naproxen and other NSAIDs before and after PRP, because they dampen the early inflammatory response that PRP is meant to support. Protocols vary widely in how long they restrict them. Ask which pain reliever is safe to use instead, and never stop a prescribed blood thinner without talking to the doctor who prescribed it.

Are PRP injections painful?

The area is usually numbed, so the injection itself is brief. Soreness and swelling afterward are common and typically settle within a day or two, though the American Academy of Orthopaedic Surgeons notes that injection-site pain can increase for the first week or two.

How many PRP injections will I need?

It depends on the condition. Some people respond to one injection, and others need a series. In knee osteoarthritis, a 2021 meta-analysis found three injections given about a week apart worked better than a single injection over 12 months.

How much does a PRP injection cost, and does insurance cover it?

A survey of 179 U.S. centers found an average price of $714 for a single knee PRP injection, and prices vary by clinic, region, the body area treated and whether ultrasound guidance is used. Few insurance plans reimburse PRP, so most patients pay out of pocket. Ask for a written quote before treatment.

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