Modern red light therapy is roughly 59 years old. Its modern scientific history began in 1967, when Hungarian physician Endre Mester observed that low-power ruby laser light appeared to improve hair regrowth and wound healing in laboratory animals. Researchers now commonly refer to this treatment as photobiomodulation therapy, or PBM.
Therapeutic light has a longer history. In the early 1900s, Danish physician Niels Finsen used concentrated light to treat skin conditions. He received the 1903 Nobel Prize in Physiology or Medicine for his work. The red and near-infrared light therapy used in clinics and home devices developed later, following the invention of the ruby laser in 1960.
Red Light Therapy History at a Glance
| Period | Development |
|---|---|
| 1903 | Niels Finsen received the Nobel Prize for therapeutic applications of concentrated light. |
| 1960 | The first working ruby laser was developed. |
| 1967 | Endre Mester's experiments helped establish modern low-level light therapy. |
| 1990s | Researchers began developing larger red and near-infrared LED systems. |
| 2000s onward | LED-based photobiomodulation became more practical for medical, clinical and consumer devices. |
What Happened in 1967?
Endre Mester was testing whether laser light could affect tumors. His low-power ruby laser did not destroy the tumors, but the treated animals showed faster hair regrowth and improved wound healing. The result led to further research into low-level laser therapy, the earlier name for photobiomodulation.
Modern photobiomodulation generally uses red or near-infrared light without heating the tissue. Red light is commonly used for more superficial tissues, while near-infrared light can reach deeper into tissue. Researchers have studied the therapy for wound healing, pain, inflammation and tissue repair. Results vary with the wavelength, dose, treatment schedule and condition being treated.
When Did LED Red Light Therapy Become Popular?
LED red light therapy became more important during the 1990s and early 2000s. Early research focused mainly on lasers, but LED panels could cover larger treatment areas and were less expensive and easier to operate than many laser systems.
NASA-funded research also helped advance medical LED applications. NASA and its research partners studied red and near-infrared LEDs for wound healing and other medical uses. The projects built on LED systems first developed for growing plants in space and took place from the 1990s into the early 2000s.
Is Red Light Therapy New?
Red light therapy is not new. Its modern scientific history goes back to 1967, while therapeutic light more broadly has been studied since the early 1900s.
The recent growth of home-use masks, panels and handheld devices reflects improvements in LED manufacturing and wider consumer access. It does not mark the discovery of an entirely new treatment. In scientific research, the treatment is usually called photobiomodulation. Older sources may call it low-level laser therapy or low-level light therapy.