By Dr. Jeffrey Peng, MD · Published March 6, 2026 · 8 min read Watch the Full Video Platelet-rich plasma ( PRP ) injections have become a widely studied treatment option for tendon conditions such as tennis elbow, fascial problems such as plantar fasciitis, and joint conditions such as osteoarthritis. PRP is increasingly used as a first-line therapy because it is both safe and effective. However, one often-overlooked factor that can significantly influence your outcomes is t