Red light therapy has roots stretching back over 125 years. While the consumer devices you see today are relatively new, the medical use of light to heal tissue dates to the 1890s, and the specific science behind red and near-infrared wavelengths has been building since the 1960s. The technology’s path from a Nobel Prize-winning treatment to a mainstream wellness product is a surprisingly long one.
The First Medical Use of Light Therapy
The story begins with Danish physician Niels Ryberg Finsen, who in 1895 used concentrated beams of ultraviolet light to treat patients with lupus vulgaris, a form of tuberculosis that attacks the skin of the face and neck. His results were promising enough that he won the Nobel Prize in Physiology or Medicine in 1903, specifically for “his contribution to the treatment of diseases, especially lupus vulgaris, with concentrated light radiation.” The Nobel committee noted that Finsen had “opened a new avenue for medical science.”
Finsen’s work used ultraviolet light rather than red or near-infrared wavelengths, so it wasn’t red light therapy as we know it. But it established a critical principle: that specific wavelengths of light could produce measurable biological effects in human tissue. That idea laid the groundwork for everything that followed.
Low-Level Laser Therapy in the 1960s
The more direct ancestor of modern red light therapy emerged in the 1960s, shortly after the invention of the laser. Researchers began experimenting with low-power lasers, particularly in the red and near-infrared range, to see if they could stimulate healing. This field became known as low-level laser therapy, or LLLT. Early studies were scattered and inconsistent, but they kept pointing toward something real: cells exposed to red and near-infrared light seemed to behave differently, healing faster and producing less inflammation.
Over the following decades, scientists worked to pin down why this happened. The leading explanation centers on an enzyme deep inside your cells’ mitochondria, the structures responsible for producing energy. This enzyme is the final link in the chain that converts food into cellular fuel. When red or near-infrared light hits it, the enzyme absorbs that light and becomes more active, boosting energy production within the cell. That extra energy appears to kick off a cascade of effects: faster tissue repair, reduced inflammation, and increased blood flow. Research on isolated rat liver cells showed that exposure to red laser light increased energy production, the electrical charge across the mitochondrial membrane, and the chemical gradient that drives the whole process.
NASA’s Role in the 1990s and 2000s
Red light therapy got a major credibility boost from an unlikely source: NASA. In the 1990s, researchers at NASA’s Marshall Space Flight Center began experimenting with LEDs (light-emitting diodes) for growing plants in space. They noticed something unexpected. The red wavelengths that helped plants grow also seemed to accelerate wound healing in human tissue.
This observation launched a formal medical research program led by Harry T. Whelan, M.D. The primary goal was practical and urgent: astronauts on long-duration space missions needed better ways to heal injuries. In the microgravity environment of space, wounds heal more slowly, and a treatable injury could easily become a mission-ending problem. LED-based light therapy offered a compact, low-power solution that could be carried aboard spacecraft.
The results from early trials were striking. An LED array combining three wavelengths (670, 720, and 880 nanometers) was tested on Navy SEAL team members during training. Musculoskeletal injuries improved by more than 40% compared to untreated controls. In another test aboard a U.S. Naval submarine, crew members’ lacerations healed in about 7 days with LED treatment versus roughly 14 days without it, a 50% faster healing rate. These weren’t lab experiments on cell cultures. They were real injuries on active-duty military personnel, and the improvements were hard to ignore.
NASA’s involvement was a turning point for two reasons. First, it validated the shift from expensive, finicky lasers to affordable LED arrays, which could deliver similar wavelengths at a fraction of the cost. Second, it gave the field institutional credibility that decades of smaller studies hadn’t quite achieved.
From Clinical Tool to Consumer Product
Through the 2000s and 2010s, the research base expanded rapidly. Studies explored red and near-infrared light for skin health, joint pain, muscle recovery, hair regrowth, and oral health, among other applications. The FDA cleared certain red light devices for specific uses like pain relief and anti-aging skin treatments, which opened the door for consumer marketing.
In 2014, the field formalized its terminology. The term “photobiomodulation” (PBM) was officially adopted as a unifying label, replacing the patchwork of names that had accumulated over decades, including LLLT and “cold laser therapy.” The name change reflected a broader understanding: this wasn’t just about lasers anymore, and the biological effects were well-documented enough to deserve a precise scientific term.
The consumer market exploded in the late 2010s and early 2020s. LED panels, handheld wands, face masks, and full-body beds became widely available online and in wellness clinics. Prices dropped as LED manufacturing costs fell, making devices accessible to anyone willing to spend a few hundred dollars. The underlying technology in these consumer products is essentially the same as what NASA tested on Navy SEALs, though the power output, wavelength precision, and treatment protocols vary widely between brands.
A Timeline at a Glance
- 1895: Niels Finsen uses concentrated light to treat skin tuberculosis
- 1903: Finsen wins the Nobel Prize for light-based medical treatment
- 1960s: Low-level laser therapy research begins after the invention of the laser
- 1990s: NASA discovers LED wavelengths used for plant growth also affect human tissue
- Early 2000s: NASA-funded trials show 40-50% improvements in wound healing
- 2014: “Photobiomodulation” formally adopted as the scientific term
- Late 2010s onward: Consumer red light devices become widely available
So red light therapy, in the broadest sense, has been around for well over a century. The specific use of red and near-infrared wavelengths dates to the 1960s. And the affordable LED-based version that most people encounter today traces directly to NASA research from the 1990s.