Osteoarthritis (OA) is a common disease involving joint damage, an inadequate healing response and progressive deterioration of the joint architecture. Autologous blood-derived products such as plateletrich plasma (PRP) are key sources of molecules involved in tissue repair and regeneration. In pathological conditions such as OA, these products can deliver a collection of bioactive molecules that have important roles in fundamental processes, including inflammation, angiogenesis, cell migration and metabolism. PRP has anti-inflammatory properties through its effects on the canonical nuclear factor κB signalling pathway in multiple cell types including synoviocytes, macrophages and chondrocytes. PRP contains thousands of different molecules; cells within the joint add to this milieu by secreting additional biologically active molecules in response to PRP.