38 million people in the U.S. that has migraines or study published in a 2016 issue of Brain shows that green LED lighting reduced pain intensity by 20 percent. In the study, “Migraine photophobia originating in cone-driven retinal pathways,” researchers at the Beth Israel Deaconess Medical Center set out to test whether or not colors can affect photophobia and migraine intensity. Photophobia is sensitivity to light and can be associated with pain and migraine exacerbation. Findings in a previous study fueled the motivation for this study. In the earlier study, the researchers found that blind participants experienced increased migraine pain when exposed to blue light.

Sixty-nine participants with migraines were part of the most recent study. Researchers studied the effects that exposure to white, blue, green, amber, and red low-intensity light had on their pain. Blue and red light were the worst—increasing pain by 18-19 percent. White and amber increased pain by 15 percent. Green was the only color that reduced pain.

Another green-light study found that exposure to low-intensity light from green LEDs reduced chronic pain and migraine severity. In this study, eight participants with fibromyalgia or migraines were given a green LED strip light, and five were given a white strip. Participants were asked to use their strips nightly for one to two hours for 10 weeks. Participants with green LEDs reported a 40-50 percent drop in pain.

The study was so successful for some that they asked to keep their green LED strip lights; they continue to use them in addition to or in place of medicine. In a study was published in a 2017 issue of Pain. The University of Arizona study, “Long-lasting antinociceptive (pain blocking) effects of green light in acute and chronic pain in rats,” found that rats experienced an increased tolerance for thermal and tactile testing methods. These tests measured how long it took for the rats to withdraw their paw when exposed to heat or pricked with a filament. Testing was completed under green or white light. The researchers found that after eight hours of green LED light exposure for five days it took much longer for rats to withdraw their paws. Effects of the green LEDs lasted for four days.

Rajesh Khanna, UA associate professor of pharmacology and senior author of the study, reports that, “While the pain-relieving qualities of green LED are clear, exactly how it works remains a puzzle. Early studies show that green light is increasing the levels of circulating endogenous opioids, which may explain the pain-relieving effects.”  In a UA article, “(Exogenous) Opioids, while having many benefits for managing pain, come with serious side effects.” These medications can also be addictive.

Researchers in this study are not advising people to stop their medications without speaking with a professional. However, it is possible, as in Lesneski’s case, that green LED lighting could eliminate the need for them in the future. “We need safer, effective and affordable approaches, used in conjunction with our current tools, to manage chronic pain,” Ibrahim said.