What is the origin of low level laser therapy? Who really invented laser therapy? In 1965, Hungarian Physician Dr. Endre Mester was testing the effects of lasers on mice. To allow for easier penetration, he shaved the mice’s hair. He soon noticed that hair on mice grew back much quicker than mice unexposed to laser light. Curious, Dr. Mester soon discovered that his assistant had accidentally turned the laser power down to a very low capacity. This emitted a cold or “low-level” laser. Today, Dr. Mester is recognized as the father of Low-Level Light Therapy, otherwise called Laser Phototherapy.