Platelet-rich plasma (PRP) therapy is a regenerative medicine technique that uses a concentration of a person’s own platelets to accelerate healing in injured tendons, ligaments, muscles, and joints. The procedure involves drawing a small amount of blood, processing it to isolate and concentrate the platelets, and then injecting the resulting solution back into the site of injury. Because the substance being injected is autologous—meaning it comes from the patient’s own body—the risk of allergic reaction or disease transmission is extremely low. However, like any medical injection, the procedure carries certain risks, and patient selection and technique play a significant role in determining whether a treatment is successful or could potentially lead to a worsening of symptoms.
Expected Temporary Discomfort
The most common reactions following a PRP injection are generally temporary and reflect the body’s intended healing response rather than an injury getting worse. Patients frequently experience localized pain, swelling, and tenderness at the injection site, often described as a deep ache or soreness. This temporary discomfort is largely due to the inflammatory cascade initiated by the concentrated platelets and the physical trauma of the needle itself.
This initial inflammatory phase is an anticipated part of the healing process, as the platelets release growth factors that signal the body to begin tissue repair. The symptoms, which may also include minor bruising and redness, typically peak within the first 48 to 72 hours following the injection. Over-the-counter pain relievers, such as acetaminophen, may be used for comfort, but non-steroidal anti-inflammatory drugs (NSAIDs) are usually avoided because they can interfere with the very inflammatory process the PRP is meant to trigger.
Potential Serious Complications
While the inherent risks of the PRP solution itself are minimal, certain rare but serious complications can occur, primarily linked to the injection procedure, which could genuinely make an injury feel worse. The most concerning risk for any injection is infection at the site, which can occur if sterile techniques are not rigorously followed during the blood draw, processing, or injection. An infection, though uncommon, can lead to increased pain, warmth, and swelling that persists beyond the initial few days, potentially progressing to a severe issue like cellulitis or an abscess.
Another serious risk is iatrogenic nerve or tissue damage, which happens when the needle accidentally strikes a nerve or injects the solution into an unintended structure. This procedural error can cause temporary or, in rare cases, prolonged symptoms like numbness, tingling, or localized weakness in the affected limb. Practitioners often use image guidance, like ultrasound, to ensure precise needle placement and avoid nearby anatomical structures. Extremely rare adverse inflammatory responses, such as the formation of granulomas or excessive scar tissue, have also been reported, where the body overreacts to the injected material.
Conditions That Rule Out PRP
In certain medical scenarios, the use of PRP is contraindicated because it either increases the risk of a complication or prevents the treatment from working effectively. Patients with active systemic infections or local infections at the injection site should not receive PRP until the infection is completely cleared, as introducing the needle could spread bacteria. Certain blood disorders that affect platelet count or function, such as severe thrombocytopenia (low platelet count), also make the treatment ineffective because the concentrated solution would not contain the necessary growth factors.
The use of specific medications can also rule out treatment, as they directly interfere with the platelets’ ability to function. Patients taking chronic anticoagulant medications, or blood thinners, may be at a higher risk for excessive bleeding or bruising at the injection site. Since PRP relies on the body’s natural inflammatory cascade, taking corticosteroids or NSAIDs shortly before or after the procedure may compromise the regenerative effect. Patients with a history of certain cancers, particularly those affecting the blood or bone marrow, are typically advised against PRP due to theoretical concerns that growth factors could stimulate cancer cell growth.
Ensuring Safe Treatment
Minimizing the potential for adverse outcomes largely depends on procedural precision and appropriate patient selection before the injection takes place. Patients should select a provider who is experienced in regenerative medicine and follows strict aseptic techniques to eliminate the risk of infection. An experienced practitioner will also conduct a thorough pre-procedure screening to identify any contraindications, such as blood disorders or the use of interfering medications.
The use of image guidance, particularly ultrasound, is an important practice that significantly enhances safety by allowing the provider to visualize the needle’s trajectory in real-time. This visualization helps ensure the PRP is delivered precisely to the damaged tissue, avoiding unintended structures like nerves or blood vessels. Following post-procedure instructions, which often include a brief period of rest and avoiding strenuous activity, is also an actionable step patients can take to support the healing process and allow the concentrated growth factors to begin their work.