What Is PRP Injection and How Does It Work?

Platelet‑rich plasma (PRP) injections use a small sample of your own blood. The blood is taken and spun in a machine to separate and concentrate the platelets. The platelet-rich plasma is then injected into the painful or injured area to encourage healing. Because it uses your own blood, PRP is considered a safe, autologous treatment with low risk of rejection.

Curious to find out what PRP injection is, how effective it can be, what it treats best, and whether it might help your recovery or pain relief without surgery? We’ll walk you through the science, the evidence, and what to expect from treatment.

How Do PRP Injections Work?

As introduced above, PRP injections work by taking a small sample of your blood and spinning it in a centrifuge to concentrate the platelets into plasma. These platelets are packed with growth factors, including vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor beta (TGF-β). Each plays a role in tissue repair, blood vessel formation, and reducing inflammation.

Once prepared, the PRP is injected into the target area. In musculoskeletal medicine, injections are often delivered under ultrasound guidance. This imaging allows the us to see exactly where the needle is placed, ensuring that the plasma reaches the injured tendon, ligament, or joint surface. After injection, the growth factors gradually stimulate the body’s repair response, improving blood flow, reducing inflammation, and encouraging new tissue formation.

Keep in mind that this process does not provide instant results. Instead, most patients notice changes gradually over the following weeks, as the repair mechanisms continue to work.

How Effective is a PRP Injection?

The question of how effective a PRP injection is depends on the condition being treated and on individual patient factors. Research suggests PRP is particularly helpful in several areas:

• Osteoarthritis: Especially in the knee, PRP injections have been shown in randomised controlled trials to reduce pain and improve mobility for several months at a time. Some studies indicate PRP may provide longer-lasting relief than hyaluronic acid injections, though results are still mixed and research continues.

• Tendon injuries: PRP has been used successfully in conditions such as tennis elbow, jumper’s knee, and Achilles tendonitis. Patients often report faster recovery and less ongoing pain compared with physiotherapy alone.
• Post-surgical healing: Surgeons sometimes use PRP to support healing after ligament or tendon repair. The growth factors may help reduce swelling and accelerate recovery.

Compared with corticosteroid injections, PRP generally offers slower but longer-lasting results. Cortisone can provide rapid relief, but its effect may wear off quickly, and repeated use can weaken your body’s tissue.  By contrast, PRP aims to strengthen and repair rather than simply mask symptoms.

It is important to note that results are not guaranteed. Some patients experience significant improvements, while others notice only modest change. Multiple sessions are often needed, and your consultant will advise you on the most appropriate treatment plan.

Conditions Commonly Treated with PRP

PRP therapy is widely used in musculoskeletal and orthopaedic medicine. The conditions most often treated include:

• Arthritis and joint pain: Particularly knee, hip, and shoulder osteoarthritis, where PRP may help reduce pain and improve mobility.
• Tendinopathy: Chronic tendon problems such as tennis elbow, rotator cuff injuries, and Achilles tendonitis that are slow to heal.
• Ligament injuries: Including partial tears and persistent sprains such as anterior cruciate ligament (ACL) damage.
• Muscle injuries: Strains in the hamstring, quadriceps, or calf muscles, often seen in active individuals and athletes.
• Post-surgical recovery: To limit inflammation and support the healing process after orthopaedic procedures.

By addressing these conditions, PRP injections provide a non-surgical option that can support natural healing, reduce symptoms, and help patients return to daily activities more comfortably.

What to Expect from Treatment

A typical PRP appointment lasts less than one hour. After a consultation with your specialist, a small blood sample is taken. The blood is processed in a centrifuge on site, which takes around 15 minutes. Once the PRP is prepared, the injection is carried out, often with ultrasound guidance to ensure accuracy.

The injection itself usually causes only mild discomfort, similar to a standard blood test or vaccination. Some patients experience temporary soreness or swelling at the injection site, but this usually resolves within a couple of days.

You should be able to return to normal activities quickly, but we may recommend avoiding strenuous exercise for a short time. It is also common to be advised against taking anti-inflammatory medication such as ibuprofen immediately after treatment, as it can interfere with the repair process.

Many patients begin to notice changes after three to six weeks, with full benefits developing over a longer period. Depending on the condition, more than one injection may be required for optimal results.

Risks and Safety Information

PRP injections are generally very safe when carried out by trained medical professionals. Side effects are minor and usually limited to temporary pain, swelling, or bruising at the injection site. Because PRP is prepared from your own blood, there is no risk of allergic reaction or immune rejection.

Serious complications such as infection or nerve damage are extremely rare, particularly when the injection is performed under sterile conditions. PRP may not be suitable for patients with certain blood disorders, active infections, or a history of cancer. We will review your medical history carefully before recommending treatment.

Research and Evidence

PRP has been studied extensively over the past decade, with hundreds of clinical trials published worldwide. The strongest evidence for PRP is in the treatment of knee osteoarthritis and chronic tendon injuries. Systematic reviews suggest PRP is more effective than placebo and, in some cases, superior to hyaluronic acid injections.

In the United Kingdom, NICE (National Institute for Health and Care Excellence) acknowledges the growing role of PRP but notes that further research is ongoing. Internationally, regulatory agencies such as the FDA and MHRA consider PRP safe but continue to evaluate its long-term effectiveness.

By staying informed of the latest studies, clinics like Regenesis ensure that treatment recommendations are grounded in current evidence and best practices.

Where to Get PRP Injections

Knowing where to get a PRP injection is important, as the procedure should always be performed in a clinical setting by specialists trained in regenerative medicine and orthopaedics. Ultrasound guidance is often used to ensure the injection is delivered accurately, and sterile technique is essential for safety.

At Regenesis, our consultants specialise in regenerative orthopaedic care. We assess each patient individually, tailoring treatment to their condition and goals. PRP is offered as part of a broader programme of non-surgical therapies designed to relieve pain, restore movement, and improve quality of life.

If you would like to know whether PRP is suitable for you, we encourage you to book an appointment or make an enquiry with our team.