Dr. Phil Harrington, DC, is widely recognized as the World's Foremost Proponent of Class 4 Laser Therapy. A graduate of Iowa State University with a BS in Physics, and of Palmer College of Chiropractic, he was in private practice for ten years and has been educating clinicians on photobiomodulation for 20+ years. As Medical Director of Summus Medical Laser, Dr. Harrington shapes the clinical direction of one of the leading photobiomodulation companies in the world, specializing in Class 4 therapy lasers and whole-body PBM beds. His mission is to advance individualized, evidence-based laser protocols that empower clinicians and transform patient outcomes. Dr. Harrington has trained healthcare professionals across the United States and in more than 23 countries, lecturing at international conferences and authoring numerous articles on photobiomodulation. His clinical interests span pain management, arthritis, sports and orthopedic injuries, migraines, and emerging applications such as idiopathic pulmonary fibrosis. A passionate educator and writer, Dr. Harrington draws on decades of hands-on clinical experience and global teaching to translate complex laser science into practical, accessible knowledge. His books are designed as trusted resources for clinicians seeking to integrate Class 4 laser therapy into their practice with confidence and skill.